While CDFW has developed protocol guidelines on how to displace burrowing owls from nests prior to destroying their burrows (Staff Report on Burrowing Owl Mitigation 2012), it has not enforced those in any meaningful way either. These guidelines are not regulations and cannot authorize take. Any benefit these guidelines have provided has been insufficient to avoid the continued loss of habitat and drastic decline of the species, which further reinforces the need for CESA protections.
The guidelines focus on preventing direct take; they do not address the destruction of unoccupied burrows or previously occupied burrows outside of the nesting season, which often serve as future owl nesting habitat. Burrowing owls, because of their subterranean habitats, also often go undetected. The guidelines’ narrow focus has resulted in the inadvertent killing of burrowing owls and the destruction of their nests and habitat by ground-disturbing activities, such as permitted bulldozing and unregulated activities such as plowing, disking, or grading.
Similarly, the guidelines also encourage active and passive relocation, which subject burrowing owls to “serial evictions” (Hennessy et al. 2022). Such actions force the subject owls to relocate with no assurances that alternative burrows or suitable habitat exist nearby (Hennessy et al. 2022). Consequently, relocation, though state-sanctioned, often results in the disguised or delayed take of owls. CDFW’s implementation of the guidelines thus fails to address the clear 153
“take” of owls and their nests and eggs, which the Fish and Game Code prohibits but regularly occurs.
State Policy on Burrowing Owl Mitigation
In the absence of endangered species laws or state agency guidelines to protect an obviously declining species, and in an attempt to develop a consistent, logical means for avoiding direct owl mortality, defining impacts, and suggesting reasonable mitigation, the biological community formed the California Burrowing Owl Consortium (CBOC) in 1989. The CBOC prepared a document entitled “Burrowing Owl Survey Protocol and Mitigation Guidelines” in 1993, intended to standardize determinations of owl presence and impact assessment (CBOC 1997). After submission of this document, CDFG subsequently prepared a “Draft Staff Report on Burrowing Owl Mitigation,” which borrowed extensively from the CBOC’s document (CDFG 1995). The CDFG (1995) report was intended to assist CDFG staff in reviewing CEQA for projects which may impact owls and their habitat.
The CBOC guidelines were intended to assist individuals (in the private or agency sectors) faced with mitigating direct impacts to burrowing owls; this document was not intended to address region-wide, long-term conservation planning for the species. The guidelines were widely used by agency and private biologists from 1994 to the early 2000s, and were badly misused and misinterpreted. In trying to determine a number that represented an impact threshold, CBOC took into account the fact that owls move, sometimes long distances (e.g., Haug and Oliphant 1990), and also nest in areas that might appear to have only a small proportion of suitable habitat. The threshold question hinged on how close development could come to a burrow without a significant impact and whether projects with a modest footprint (e.g., pipelines and transmission lines) could be declared to have significant impacts to an owl home range encompassing scores, if not hundreds of acres. Using a combination of intuited disturbance distances (a few dozen meters) and territorial considerations, biologists with the CBOC selected a 300-foot radius around an occupied burrow (6.5 acres) as the amount of habitat estimated to be a threshold where significant impacts should be considered. This area was not purported to be the amount of habitat needed to support a pair of burrowing owls, nor was it meant to be used as a way to manage for a sustainable population of owls.
CDFG subsequently used the 6.5 acre figure as acceptable mitigation for impacts to breeding owl pairs. The replacement acreage did not have to be in the vicinity of the project and it did not have to be in place for 2 years. Unofficial “owl banks” and then later approved conservation banks in eastern Contra Costa County were used for mitigation for South Bay development projects, re-enforcing the perception that CDFG had abandoned efforts to protect owls in the urban Bay Area. CDFG applied this mitigation requirement of conservation and long-term management of 6.5 acres of existing burrowing owl habitat to at least 84 owl pairs directly impacted by development activities from 2000-2003, within the southern and eastern portions of the Bay Area (Contra Costa, Alameda, and Santa Clara Counties) (CDFG 2002a, 2003). Use of these conservation banks as acceptable mitigation preserved only a very small amount of burrowing owl habitat in exchange for the likely eventual extirpation of owl populations from the eastern and southern Bay Area. And use of the 1995 guidelines facilitated local extirpations without requiring any evidence of survivorship or successful breeding of relocated owls. CDFG (2003) felt that the staff report helped conserve burrowing owls and their habitat and that offsite mitigation may be more biologically viable for burrowing owls by permanently securing larger blocks of contiguous, less fragmented habitat. CDFG (2003) acknowledged the limitations of the 1995 staff report and concurred that offsite mitigation may lead to local onsite burrowing owl extirpation, but maintained that offsite mitigation was a valuable alternative tool which could 154
provide an incentive to lead agencies that determine that onsite conservation efforts are too costly. Which underscores the need for CESA listing of Burrowing owl populations, so that the profit margins of development projects are not driving burrowing owl conservation approaches.
In 2012, CDFG updated and replaced the 1995 staff report to better protect burrowing owls.
CDFG (2012) recommended revised avoidance, minimization and mitigation approaches for burrowing owls. One of the main changes in the guidelines from 1995 to 2012, was that the amount of mitigation acreage for impacts to breeding owl pairs was changed from a fixed 6.5 acres to a flexible, un-predetermined amount, with guidance from CDFG based on local observation and site-specific conditions. There is no longer any 6.5 acre requirement for impacts to owl foraging habitat, but the mitigation acreage is based on local natural history.
CDFG eliminated the 2:1 requirement for burrow replacement with artificial burrows, with the updated mitigation based on site-specific conditions. The new guidance requires more rigorous burrowing owl survey methods, improved impacts assessments, developing clear and effective avoidance and minimization measures, and developing mitigation measures to ensure impacts to burrowing owls are effectively addressed at the project, local, and/or regional level.
The 2012 report gives examples of activities that have the potential to take burrowing owls, their nests or eggs, or destroy or degrade burrowing owl habitat. It outlines steps for project impact evaluations: habitat assessment; surveys, and impact assessment. CDFG is available to assist in the development of site-specific avoidance and mitigation measures. Methods for avoidance of impacts include take avoidance, pre-construction surveys, site surveillance, minimizing impacts, buffers, and burrow exclusion and closure.
Project proponents are supposed to provide CDFW with more detailed information to assist in development of mitigation measures, such as information about: foraging (link between field irrigation methods and owl foraging); buffer strips; how much land is required to sustain the necessary amount of food (invertebrates and mammals) for owls; prey surveys on cropland (crop type and irrigation); diet analysis; and determining foraging distances on a project site.
The 2012 guidelines still allow owl eviction and burrow closure, with replacement by artificial burrows. The 2012 guidelines acknowledge (italics added):
The long-term demographic consequences of active and passive ev iction techniques have not been thoroughly evaluated, and the fate of evicted or excluded burrowing owls has not been systematically studied. Because burrowing owls are dependent on burrows at all times of the year for surv ival and/or reproduction, evicting them from nesting, roosting, and satellite burrows may lead to indirect impacts or take. Temporary or permanent closure of burrows may result in significant loss of burrows and habitat for reproduction and other life history requirements. Depending on the proximity and availability of alternate habitat, loss of access to burrows will likely result in varying levels of in creased stress on burrowing owls and could depress reproduction, increase predati on, increase energetic costs, and introduce risks posed by having to find an d compete for available burrows. Therefore, exclusion and burrow closure are not recommended where they can be avoided. The current scientific literature indicates consideration of all possible avoidance and minimization measures before temp orary or permanent exclusion and closure of burrows is implemented, in order to avoid take.
Passive relocation requires monitoring to determine the fate of evicted owls and site fidelity after relocation; and artificial burrows require better success evaluation (with banded individuals) and 155
information about configuration. The 2012 guidelines state that CDFG can not authorize translocation (active relocation offsite >100 meters) at that time due to little published information regarding the efficacy of translocating burrowing owls. Currently, active relocation or translocation is not approved by CDFW unless part of permitted scientific research or in an approved NCCP conservation strategy.
The 2012 guidelines detail methods for mitigating permanent impacts to burrowing owls, including permanent conservation of similar vegetation communities with fossorial mammals, and permanently protecting (ideally adjacent or proximate) mitigation land through a conservation easement. A mitigation land management plan is required to be developed and implemented, with long-term funding mechanism. Mitigation may include artificial burrows, with semi-annual to annual cleaning and maintenance and/or replacement (though this is not always being done or enforced). Mitigation for temporary impacts is restoring temporary disturbed areas to the pre-project condition.
Monitoring and reporting on mitigation measures is supposed to be done through the CEQA process. See the discussion above regarding the inadequacies and failures of monitoring and reporting under CEQA. Mitigation projects are supposed to provide CDFG with breeding and non-breeding season surveys and reports. The 2012 guidelines have example components for burrowing owl artificial burrow and exclusion plans, Mitigation Management Plans and Vegetation Management Goals, and Mitigation Site Success Criteria.
A 2014 CDFW report on implementation of the 2012 guidelines (Riesz and Rodriguez 2014) stated that CDFW is developing further information about resident vs. migrant owls, disturbance studies, appropriate buffers, and minimization measures. Studies as part of HCP/NCCPs are evaluating farming/drain maintenance impacts, active relocation, and appropriate distances between project site and mitigation lands. CDFW was working with applicants for energy projects to establish conservation easements for burrowing owls, to ensure the land will be retained in agricultural use compatible with burrowing owl forage and to prevent use that will impair or interfere with those values. Energy projects applicants are providing artificial burrows to compensate for directly impacted burrows.
The 2012 guidelines anticipated meaningful protection for burrowing owls will mostly be accomplished by incorporating burrowing owl conservation strategies into landscape-based planning efforts through NCCPs and HCPs. See the discussion above on the limited success of HCPs and NCCPs in protecting significant burrowing owl populations.
The 2012 guidelines have lofty and laudable conservation goals: maintaining the size and distribution of extant burrowing owl populations; increasing the geographic distribution of burrowing owls into formerly occupied historical range; increasing the size of existing populations where possible and appropriate; protecting and restoring self-sustaining ecosystems or natural communities which can support burrowing owls at a landscape scale, and which will require minimal long-term management; minimizing or preventing unnatural causes of burrowing owl population declines; and augmenting/restoring natural dynamics of burrowing owl populations including movement and genetic exchange among populations.
Unfortunately, none of these goals have been accomplished since 2012.
The new guidelines are not resulting in widespread protection of California’s burrowing owls.
Nothing in the guidelines is binding on lead agencies that make the decisions about project impacts and mitigations. It is used as guidance by CDFW during reviewing and commenting on environmental documents and making recommendations to avoid, minimize, and mitigate 156
potential negative impacts, but success depends entirely on CEQA lead agencies to adopt and enforce the guidelines, unless a permit is required that CDFW can influence. Since CDFW does not enforce take under Fish and Game Codes or the MBTA, and the burrowing owl is not a state listed species, there is little incentive for CEQA lead agencies to adhere to the 2012 guidelines.
State Conservation Strategy
The need for a range-wide conservation strategy for the burrowing owl was recognized in 1995 (CDFG 1995). After the 2003 listing petition, CDFG announced at the 2003 state burrowing owl symposium in Sacramento that it was preparing a statewide conservation strategy. In 2007, CDFG (Burkett and Johnson 2007) stated it would be completed in 2008. CDFW reportedly started developing a Burrowing Owl Comprehensive Conservation Strategy, based on the approach in the 2012 staff report. This strategy was going to be a guidance document, not a regulatory mechanism, relying heavily on voluntary adoption of conservation measures. No strategy has been put in place for the past 28 years, other than what is implied in CDFW (2012).
State Conservation Banks and Preserves
Starting in the 1990s, the California Department of Fish and Game unofficially sanctioned the use of small mitigation banks in eastern Alameda and Contra Costa Counties to “mitigate” for the loss of burrowing owl habitat to urban development in eastern and southern San Francisco Bay Area. These included the Byron Conservation Bank, Brushy Creek Conservation Bank, and the Haera Conservation Bank. Credits are purchased in exchange for permits allowing destruction of known owl breeding habitat, and usually passive eviction of owls from a project site. CDFG viewed conservation banks as a valuable conservation tool when impacts to burrowing owls from projects were “unavoidable” (CDFG 2003). CDFG moved to formally approve conservation banks that consisted of sites with occupied habitat and/or suitable unoccupied habitat, protected in perpetuity by a conservation easement, and with each bank operator providing endowment funding to manage the lands in perpetuity. The idea of these mitigation banks is to consolidate the acquisition of mitigation land, and credits for mitigation, into large and biologically meaningful parcels (CDFG 2002b).
There are a number of problems with the conservation bank approach. Due to territorial spacing, only so many burrowing owls can exist in one conservation bank; and sufficient space is also needed for seasonal shifts in activity areas. Use of these banks implicitly endorses extirpation of owls from areas of high development by not requiring on-site conservation measures, ensuring that owls will eventually be eradicated from urbanizing areas. The small number of mitigation banks with burrowing owl habitat, their small overall size (less than 25,000 acres statewide), and the rising cost of purchasing suitable land for habitat make this approach incapable of protecting significant populations of owls. A few conservation banks are co- managed by non-profit organizations with a mission to protect wildlife, but the vast majority are business ventures. Allowing for-profit ventures to assume responsibility for managing habitat in perpetuity to benefit burrowing owls is a losing proposition. There seems to be little financial incentive for management companies doing more than the primary method of "managing" for burrowing owls by keeping grass short through cattle grazing, without much else done to actively manage for owls (Breon 2015). Many sites initially managed for burrowing owls may no longer support breeding owls if vegetation management is not appropriate, artificial burrows are not maintained, predators and disturbances are not controlled, if funding (or profit margin) is short, or if other focal species take precedence over non-listed burrowing owls. The data gathering at conservation banks is weak and there are no standardized protocols, making it difficult to judge the success of any one conservation bank (Breon 2015). 157
Burrowing owls occur in relatively higher densities and numbers in habitat that is maintained by some sort of disturbance, be it livestock grazing, agricultural irrigation infrastructure operation and maintenance, or mowing (e.g., at airports). Because of their affinity for disclimax grasslands that are maintained by some sort of vegetation disturbance the conservation practice of "setting aside" habitat often fails through time to provide the short, sparse vegetation that these owls use. It is vitally important that any designated owl habitat conservation areas have rigorous management plans that ensure appropriate habitat conditions are maintained through time.
An example of problems with conservation banks is the Haera Wildlife Conservation Bank (HWCB), which was one of the first conservation banks used as supposed mitigation for eviction of breeding owls and destruction of owl habitat in Santa Clara County. Since 2001, the HWCB in eastern Alameda County and an adjacent PG&E San Joaquin Kit Fox Mitigation Site in western San Joaquin County have sold mitigation credits and purportedly been managed to protect habitat for a breeding population of burrowing owls, as well as two federally listed species (California tiger salamander and San Joaquin kit fox). In 2000, before the site was active as a conservation bank, HWCB had 10 owls and 6 active burrows, and the PG&E site had 6 owls and 3 active burrows. The Santa Clara Valley Audubon Society secured CDFG documents and the management plan for the conservation bank, which is managed by Wildlands, Inc., and published a report about the failures of the conservation bank (SCVAS 2010). Between 2001 and 2008, Wildlands, Inc. Haera Wildlife Conservation Bank sold close to 200 of its 299 acre- credits, which were used to justify multiple evictions from multiple developments in multiple counties, and representing at least 9 pairs of evicted burrowing owls (SCVAS 2010). Taking the most liberal accounting approach, both conservation sites maintained fewer than 5 owl breeding pairs as of 2010, while selling credits for at least twice that number. The management plan fails to establish population goals for any of the target species or their prey populations, does not incorporate any metrics for ecological analysis or triggers for adaptive management processes for any target species (SCVAS 2010). The plan implied that maintaining short grass habitat suffices to protect and sustain a breeding population of burrowing owls. After eight years of monitoring, there was no evidence that a viable breeding population of burrowing owls existed in HWCB. During monitoring, Wildlands Inc. often counted individual owls more than once per sampling event or per sampling year, producing data only on presence/absence of owls on the site. There was no information on breeding or fledging of burrowing owls on the site and no evaluation of the success of the conservation bank in conserving burrowing owls. Population estimates and trends could not be discerned from the data provided to CDFG. The conservation bank has sold all of its credits as of 2022 (CDFW 2023b).
Santa Clara Valley Audubon Society (SCVAS 2010) concluded that the use of off-site mitigation for burrowing owls in the manner that it was being implemented, cannot be defended as a viable conservation alternative, and petitioned CDFG to stop offering Haera or any other conservation bank as an option for mitigation for loss of burrowing owls and their habitat in Santa Clara County. Santa Clara Valley Audubon Society noted that "without a rigorous scientific approach at the implementation, monitoring, and adaptive management stages, the use of conservation banks as a conservation tool appears to be a waste of resources."
As of 2023, CDFW has 21 conservation banks in California where credits can be purchased by developers or project proponents as mitigation credits for impacts to burrowing owls (CDFW 2023a,b). There is one conservation bank for burrowing owls in the Northern Central Valley region, the 615-acre Wildlands Mitigation Bank in Placer, where 466 credits are sold out. Most (16) of the state approved conservation banks for burrowing owls are in the Middle Central Valley region, covering 10,873 acres. These include: 252-acre Dolan Ranch Conservation Bank 158
in Colusa County (297 credits of 309 sold); 1,288.5-acre Muzzy Ranch Conservation Bank (796 credits of 1209 sold) and 405-acre Jenny Farms Conservation Bank (406 credits sold out) in Solano County; 120-acre Brushy Creek Conservation Bank (118 credits sold out) in Contra Costa County; 140-acre Byron Conservation Bank (139 credits sold out), 74-acre Springtown Natural Community Reserve (73 credits sold out), 147-acre Mountain House Conservation Bank (145 credits sold out), 299-acre Haera Wildlife Conservation Bank (299 credits sold out), and the Cayetano Creek Mitigation Bank (75 acres of grasslands as of 2023) in Alameda County; 501-acre Dutchman Creek Conservation Bank (490 of 497 credits sold), 281-acre Grassland Mitigation Bank (181 of 232 credits sold), 4,131-acre Piedra Azul Conservation Bank (pending), and 3,234-acre Agua Fria Conservation Bank (3,220 credits sold out) in Merced County. There are two state conservation banks in the Southern Central Valley region, covering about 7,000 acres: the 6,059-acre Coles Levee Ecosystem Preserve (5,580 of 6,059 credits sold for energy development impacts; not for sale to the public), and 946-acre Alkali Sink Conservation Bank in Fresno County (830 of 943 credits sold). San Diego has one conservation bank, the 210-acre Ramona Grasslands Conservation Bank (74 of 199 credits sold). In the southern desert region, the 4,678-acre Mojave Desert Tortoise Conservation Bank in San Bernardino County accepts burrowing owl mitigation credits (3,081 of 4,658 credits sold). A few banks only cover overwintering or foraging habitat: 573-acre Bryte Ranch Conservation Bank in Sacramento County (235 of 264 credits sold); and 964-acre Burke Ranch Conservation Bank (668 of 920 credits sold) and 1,815-acre Elsie Gridley Mitigation Bank in Solano County (1,398 of 1,735 credits sold). Through 2022, these 19 existing banks had collectively sold 19,894 credits (CDFW 2023b).
These conservation banks are a bit of a black box, since there is minimal readily available public information about how many breeding pairs of owls are actually protected on these conservation banks, and what exactly the management plans are doing to ensure owls can persist in perpetuity, despite them being used to “mitigate” for take of known breeding pairs of owls elsewhere. The petitioners submitted a public records request to CDFW asking for information on the status of burrowing owls on all state approved mitigation and conservation banks. CDFW was only able to provide annual reports with any information for 9 of these 21 banks (Alkalai Sink, Bryte Ranch, Burke Ranch, Cayateno, Dolan, Dutchman Creek, Elsie Gridley, Grasslands, and Muzzy Ranch).
The Alkali Sink Conservation Bank in Fresno County has sold 830 credits, but only had two wintering burrowing owls documented in January of 2018; there is no evidence of breeding burrowing owls on the site (CDFW 2018). The Bryte Ranch Conservation Bank in Sacramento has sold 235 credits, and detected small numbers of wintering owls in 2005 (May & Associates 2005); 4 wintering owls observed during 2009-2014 surveys (MHB 2014); no owls and no evidence of owl usage during surveys from 2018-2022 (ECorp 2018-2022); and an unspecified number of owls flushing from five burrows on the bank on February 23, 2023, with evidence of burrowing owl usage (e.g., whitewash, owl pellets, feathers) (ECorp 2023); these were presumably wintering owls and there did not seem to be follow up later in the breeding season.
Burke Ranch Conservation Bank in Solano County has sold 668 credits; and during focused owl surveys from 2008-2022 documented no breeding owls, and only single wintering owls in 2012, 2013, 2020, and 2021 (Westervelt 2009-2023). The first year of operation of the Cayetano Creek Mitigation Bank in Alameda County, 2 burrowing owls were observed within the bank but reporting did not specify what time of year, presumably not during breeding season (Olberding 2023a). Dolan Ranch Conservation Bank in Colusa County has sold 297 credits, but despite installing artificial burrows in 2004 has not had any use at all by burrowing owls for 20 years (RES 2022). Dutchman Creek Conservation Bank in Merced County has sold 490 credits; CDFW had only one informal wildlife report stating that the burrowing owl has also been 159
observed utilizing the property as breeding habitat (Westervelt 2013), but no documentation or annual survey reports. Elsie Gridley Mitigation Bank in Solano County has sold 1,398 credits; artificial burrows have been installed and maintained; focused owl surveys since 2007 have documented no breeding owls on the bank; with 3-6 wintering owls present most years from 2007-2023 (LSA 2009-2011; WRA 2013-2020; RES 2021-2023). Grassland Mitigation Bank in Merced County has sold 181 credits; only a single wintering burrowing owl was documented on the site in November 2013, but no breeding burrowing owl observations during 2010-2014 surveys (Westervelt 2014), with no other annual reports provided. Muzzy Ranch Conservation Bank (in Solano County has sold 796 credits; despite 5+ years of focused owl surveys, there has been no evidence of successful breeding on the bank, with up to 5-6 wintering owls (LSA 2018-2022).
Thus, despite sale of nearly 20,000 credits at these 21 mitigation banks, CDFW has documentation of exactly zero pairs of breeding burrowing owls at all of these conservation banks. From the limited information CDFW seems to keep on the status of burrowing owls at these banks, it is clear that the use of these banks as mitigation results in a massive net loss of breeding owl pairs.
CDFW provided additional monitoring reports for proposed mitigation banks not yet on the list of banks accepting credits for burrowing owls, none with large breeding owl populations. These included: 1,948 acre Black Mountain Conservation Bank in San Bernardino County; 220-acre Eagle Ridge Preserve East Mitigation Site on the Contra Costa/Alameda county line; and the 2,615-acre Gabrych Study Area in San Bernardino County. During focused transect surveys for burrowing owls at Black Mountain in April 2017 no burrowing owls were observed but 6 burrows with whitewash and/or pellets were noted (Corvus 2017). Eagle Ridge Preserve East had two pairs of burrowing owls observed on the bank in 2009 and again in 2011, and one pair and four nestlings observed in summer of 2021 (Olberding 2023b). Focused surveys at Gabrych Study Area in 2015 found no evidence of breeding burrowing owls, and 2 locations with whitewash/pellets (Corvus 2015).
CDFW provided additional monitoring reports for mitigation banks that do not cover the burrowing owl, but may incidentally provide habitat. The 4,526-acre Palo Prieto Conservation Bank in northeast San Luis Obispo County and western Kern County sells credits for San Joaquin kit fox but apparently also supports burrowing owls, which are not a focal species. The Palo Prieto Conservation Bank became operational in March 2007 and had sold 3,814 kit fox credits as of 2018. Unspecified numbers of wintering burrowing owls were observed on two parcels 2009-2010; high abundance of wintering owls were reported 2010-2015; apparently “high abundance” of burrowing owls were also present during breeding season surveys (May, July and August) from 2012-2015, but no numbers, evidence or additional documentation is provided (Althouse & Meade 2009-2015); and the 2018 Palo Prieto report states that no burrowing owls were observed during 2018 (Althouse & Meade 2018). The 3,284-acre Sparling Ranch Conservation Bank in southeastern Santa Clara County and northeastern San Benito County sells credits for California tiger salamander and California red-legged frog, and supports a small number of wintering burrowing owls, which are not a focal species. There is no documentation of breeding burrowing owls; winter surveys in 2013 found signs of burrowing owl presence and one presumed transient burrowing owl was seen September 2017 (H.T. Harvey & Associates 2015-2016; Biosearch 2018-2019).
CDFW provided monitoring reports for some additional conservation areas established to mitigate for energy development project impacts:
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The 52-acre Alpaugh Conservation Easement in Tulare County was established to mitigate for destruction of burrowing owl habitat as a result of the development of the Alpaugh 50, LLC and Alpaugh North, LLC Solar Projects in Tulare County. As of the recording of the conservation easement in 2014, no breeding or wintering protocol-level surveys had been conducted on the conservation easement area, and recent observations did not yield any burrowing owls on the site, despite burrowing owl observations on adjacent sites (Sequoia Riverlands Trust 2014); CDFW provided an undated map showing 8 "active BUOW burrows" on the Alpaugh site, but no additional information.
The 634-acre Alta Oak Creek Mojave Mitigation Conservation Areas in Kern County were established to compensate for impacts to threatened and endangered species resulting from the Alta Oak Creek Mojave Wind Energy Project, the construction and operation of 100 wind turbine generators and ancillary facilities on 606 acres within the West Mojave Desert Planning Area, permitted by Kern County. The preserve surveys and supporting documents did not provide any evidence of breeding burrowing owls on these preserve sites. (Wildlands 2011, 2012). As of 2017, there were no burrowing owls detected during surveys of the Alta Oak Creek conservation areas (Corvus 2018).
California Valley Solar Ranch Project (CVSR) is a 250-megawatt solar photovoltaic energy facility in eastern San Luis Obispo County that went into operation 2012-2013, and has set aside 8,082 acres of conservation lands. Based on focused owl surveys, within the California Valley onsite conservation lands there were 6-12 documented breeding pairs of burrowing owls in 2011; 5 pairs in 2012 (that produced 18 juveniles); 7 pairs in 2013 (that produced 6 juveniles), and biologists declared the breeding population stable; there was only 1 breeding pair in 2014 and 2 breeding pairs in 2015 (that produced 15 juveniles); there were no surveys in 2016 or 2017 (H.T. Harvey and Associates 2013-2018).
A 50.2-acre mitigation parcel for the Manzana Wind Energy Project in Kern County was evaluated for burrowing owl presence in December 2012 surveys, with no burrowing owls sighted, and several kit fox burrows just offsite with signs of use by burrowing owls (Sapphos Environmental 2013).
The 407-acre Vasco Winds Ecological Preserve in eastern Contra Costa County was protected with a conservation easement to mitigate for impacts of the Vasco Winds Repowering Project, which decommissioned approximately 438 obsolete wind turbines and associated infrastructure and replacing them with 34 larger wind turbine generators in 2011. The burrowing owl is a covered species for Vasco Winds; 3 owl pairs nested on the preserve in 2013; 2 pairs nested onsite in 2014; at least 6 owls overwintered 2014-2015; but there was no evidence of nesting in 2015 or 2016, with former nesting sites overtaken by the spread of invasive black mustard (Biosearch Associates 2014-2016).
The Topaz Solar Farm Project is a 3,510 acre photovoltaic installation constructed in eastern San Luis Obispo County between 2011 and 2013. To mitigate primarily for impacts to San Joaquin kit fox, the project provided permanent protection and management of 12,168 acres of mitigation lands at North Carrizo Ecological Reserve (NCER). Based on 2010 survey data, the Topaz Solar Project would displace 2 pairs of nesting burrowing owls. During opportunistic and ineffective burrowing owl surveys from 2011-2018, large numbers of wintering burrowing owls were noted, burrowing owl locations were recorded on the preserve, nesting activity was noted but no successful reproduction was documented from 2011-2017, and no nesting activity was documented in 2018 (Althouse and Meade 2011-2013; CDFW 2015-2020). Survey techniques to better detect burrowing owl nesting and breeding on the NCER are supposed to be 161
developed and evaluated during the coming years. In 2012, Topaz Solar 2012 illegally and inappropriately installed a burrow exclusion device on an occupied nesting burrow during the nesting season, resulting in one dead adult owl and nest failure. CDFW sent a warning letter to Topaz Solar but no enforcement action was taken.
CDFW provided a proposed burrowing owl relocation, mitigation and monitoring plan for the 180-acre Corcoran Solar Generation Facility in Kings County (HEC 2013). The Conditional Use Permit and Mitigation and Monitoring Plan for Corcoran Solar required the project to conduct a pre-construction burrowing owl survey and passively relocate any owls found on the site. CDFW requested that owls be evicted outside of the breeding and nesting season (preferably before they are pairing up or after fledging; the project provide a nearby location with suitable burrows so that there is at least the opportunity for owls to relocate to adjacent habitat; the project protect that nearby location in perpetuity via conservation easement or fee title transfer to a public agency; the amount of protected habitat should be based on the amount of habitat displaced and applicable home range requirements for the number of owls displaced; and the project provide funding for initial habitat enhancement and perpetual management. The project apparently failed to meet many of these requirements. The project relied on flawed preconstruction surveys, conducted in December 2012, outside of breeding season and not according to CDFG (2012) protocols, locating 11 adult owls using 15 burrow complexes; and 9 active owl burrows in January 2013. The project would impact all of these burrows. The project proposed compensatory mitigation acreage of 109 acres; and the burrowing owl plan proposed possibly protecting 43 adjacent acres with 23 suitable burrow complexes, as well as creating berms (similar to what ground squirrels and owls were utilizing on the project site) and artificial burrows at a 2:1 ratio, if needed. The project proposed to lease the lease the 43-acre mitigation property for 60 years. Mitigation lands were supposed to be monitored with breeding season and winter surveys for a period of 5 years to determine if owls are using them, with annual monitoring reports submitted to CDFW. It is unclear if any of the monitoring or mitigation was ever done, as CDFW did not provide any further information or monitoring or mitigation reports.
The Center for Natural Lands Management (CNLM) manages numerous private mitigation preserves in California that offer mitigation credits, 10 of which are specifically managed for burrowing owls as a non-listed species; and 9 of these preserves cover only 3,038 acres (CNLM 2023). In the northern Central Valley, these include Alkali Grasslands in Yolo County, Michael Remy in Solano County, Arroyo Seco and Mehrten Ranch in Sacramento County, and Dublin Ranch in eastern Alameda and Contra Costa counties. CNLM mitigation preserves in Kings, Kern and Tulare counties include Cholame Ranch, Lost Hills, Petit, and Pixley Vernal Pools.
Lost Hills Preserve is 441 acres, with no evidence of burrowing owl breeding; 2 owl burrows were located off-site during 2012 surveys and owl foraging habitat is present on the site (CNLM 2016). In Southern California, CNLM manages the Skunk Hollow Vernal Pool (aka Barry Jones Wetland Mitigation Bank) in Riverside County. As of 2007 no breeding burrowing owls occurred on the Barry Jones/Skunk Hollow preserve, though owls breeding on adjacent lands likely forage and roost there (Stanton and Teresa 2007). The success of these preserves requires an adequate funding endowment, and adequate maintenance and monitoring criteria; and inclusion of burrowing owls in a preserve management plan must be compatible with other preserve objectives, which can focus more on listed species (Stanton and Teresa 2007). The long-term viability of owl populations on these small preserves depends in part on the future status of surrounding lands which may be developed or conserved (Stanton and Teresa 2007). The Cholame Ranch Preserve in Kings and Kern County is the only large CNLM protected area of owl habitat, with about 10,000 acres of low-elevation foothills. Other CNLM preserves where burrowing owls are not a mandated conservation target may support and benefit owls through grazing, mowing or fire programs intended to benefit other grassland species, and through 162
management strategies such as fencing and signage, trapping feral cats and dogs, removal of artificial perching sites for predators, enhancing habitat for ground squirrels, and installation of artificial nesting burrows (Stanton and Teresa 2007). But at preserves where the primary management effort is to increase habitat for listed species that require different habitats, such as shrub enhancement for the California gnatcatcher in Southern California, burrowing owls do not benefit. Preserves are also not necessarily protected in perpetuity - the former CNLM 1,008- acre March Stephen's Kangaroo Rat Preserve for the endangered Stephens' kangaroo rat in western Riverside County supported a small wintering population of burrowing owls, but this preserve was closed down to allow industrial development, in exchange for other preserve land of unknown value for burrowing owls. CNLM is proposing to manage conservation lands being used as mitigation for the Panoche Valley Solar Project, a 247 MW solar photovoltaic energy facility on 1,688 acres in eastern San Benito County; the burrowing owl is not a covered species and the draft Habitat Management Plan for approximately 25,618 acres of conservation lands does not discuss the status of burrowing owls on the conservation lands, nor contain any management efforts to support burrowing owls (McCormick Biological 2016).
Regional and Local Management Efforts
Failed conservation efforts in the San Francisco Bay Area in the 1990s and 2000s are indicative of the limitations and challenges of attempted owl conservation planning at the county and city level for non-listed species. Some jurisdictions have subsequently opted to join regional planning efforts through NCCPs and HCPs that cover the burrowing owl.
Regional Plans
Members of the CBOC met with the California Secretary of the Resources Agency in 1995 and the Director of the Department of Fish and Game in 1998 to discuss ways to enhance burrowing owl conservation in the San Francisco Bay Area other than listing the species (there was a perception that listing might lead to intentional eradication of burrows from private lands through disking). An approach involving regional conservation planning by the Department of Fish and Game and local/municipal habitat conservation was agreed upon, and the California Audubon Society introduced a bill to the California legislature in 1999. This bill would have provided funds for the Department of Fish and Game to prepare a Burrowing Owl Conservation Strategy for the Bay Area, however during legislative review this bill was amended to apply to other species and eventually was not funded. It is worth noting that every city in the southern San Francisco Bay that was approached with the concept of cooperating on a multi-city (i.e., regional) plan opted instead for its own separate plan. The result was a different approach to similar problems of habitat loss in the same locality, and the need to reinvent the process multiple times as a result of these decisions.
County Plans
The General Plans for the 37 California counties that still had breeding burrowing owls (excluding the counties in the desert range of the species) were reviewed in 2003, and none of these plans mentioned or required any mitigation for loss of burrowing owl habitat. The Fresno County General Plan typified the treatment of special status species under county level planning efforts. Protection policies were couched in qualifiers, such as “where possible,” and there is no guaranteed protection of sensitive habitat if it is “not practicable.” For example, the plan commits to “support efforts to avoid the “net” loss of important wildlife habitat where practicable” and “ensure the conservation of large, continuous expanses of native vegetation to provide suitable habitat for maintaining abundant and diverse wildlife populations, as long as this preservation 163
does not threaten the economic well-being of the county” [italics added]. The plan did not specifically mention the burrowing owl, but discussed protecting the San Joaquin kit fox in the context of mandating that the County “shall promote effective methods of pest (e. g. ground squirrel) control on croplands bordering sensitive habitat that do not place special-status species at risk, such as the San Joaquin kit fox.” Of course, effective ground squirrel control puts the long-term survival of burrowing owl populations at risk. Under the Fresno County General Plan, if protecting wildlife habitat is deemed unfeasible, “mitigation” is required.
However, compliance with existing environmental laws, such as CDFG codes, U.S. Fish and Wildlife Service regulations, and the MBTA are considered part of the mitigations. The County acknowledged that development under the plan would destroy specific habitat types that support special-status animals, and that although implementation of its mitigation policies would somewhat reduce impacts for development within the County’s jurisdiction, they would not be reduced to a less-than-significant level. The impacts of future development under the plan are deemed to be significant and unavoidable for development within the County and other city jurisdictions.
City Plans
Repeated conflicts between burrowing owls and development projects, especially in southern San Francisco Bay, have led some municipalities to consider preparing city-wide burrowing owl conservation programs for their respective jurisdictions.
The City of San Jose, in Santa Clara County, attempted the most ambitious such project in 1998 and spent two years developing a Burrowing Owl Habitat Conservation Strategy and Implementation Plan (“Plan”), which was fashioned after the Habitat Conservation Plan model for federally-listed species. The Plan would have provided a consistent way to evaluate impacts to burrowing owls and burrowing owl habitat from development according to their General Plan through 2020. The Plan proposed a development fee for every acre of open space land developed (although the fee was the most obvious way to fund the Plan, the Plan also contained other funding mechanisms) to create an endowment fund to maintain and monitor owl habitat. This funding mechanism would have resulted in the management of several hundred acres of burrowing owl habitat on dual-purpose land in San Jose, without the need to purchase prohibitively costly land (in the range of $1 million/acre). Development was expected to consume over 2,000 acres of owl habitat over 20 years, which would be mitigated by 1,250 managed acres of owl habitat within the City’s urban service area. Unfortunately, the City Council denied the Plan in May 2000 without even bothering to read it, due to objections by the building industry over the proposed development fee, concerns by the City that it would cause undue restraint of commercial development in San Jose, and the perception that they were being held to a higher standard of mitigation than neighboring entities (as in the 6.5 acres/pair mitigation for owl habitat in Byron allowed for development in Santa Clara). Shortly after the rejection of the Plan, the City, in a self-serving interpretation of the CBOC guidelines, offered a “less than significant” free pass to a development project at Lake Cunningham Park, because it impacted less than 6.5 acres of owl habitat.
The City of Morgan Hill, in Santa Clara County, began preparing a city-wide burrowing owl habitat conservation program in 2000. The City committed in 1999 to prepare such a plan as part of the approval of a development project that affected burrowing owl habitat. Unfortunately, breeding burrowing owls may have been extirpated from Morgan Hill during the time the plan was being prepared (J. Barclay, pers. comm., 2002).
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In San Bernardino County, the City of Chino General Plan authorizes low to high-density housing development on much of the agricultural land around the Chino Airport, including the majority of occupied owl locations in the vicinity of Chino (J. Bath, pers. comm., 2001). The City of Ontario General Plan proposed to convert 8,200 acres of existing agricultural grasslands, and develop 31,000 homes in an area that supports a large burrowing owl population in the Inland Empire with only a mere 50 acres of raptor habitat provided as “mitigation” (G. Stewart, D.
Guthrie, pers. comm., 1997). Litigation over this plan resulted in a settlement offering some burrow owl protection measures, which were likely inadequate to protect the owls (J. Bath, pers. comm., 2003).
A local management plan emphasizing on-site relocation and off-site habitat replacement (outside of the Santa Clara Valley) was developed for the Mission College owl population in Santa Clara County, where owl numbers have fallen from 30 pairs to 8 pairs in 5 years (Trulio 2002). This type of offsite habitat replacement is detrimental to local owl populations in the Santa Clara Valley region and the affected owls will lose most of their foraging habitat to development under this plan. The inevitable loss of the Mission College population is a perfect example of the simple relationship between habitat loss and species extirpation. (Delevoryas 1997; Trulio 1998a, 2002).
Because private lands in the City of Davis were frequently being tilled, disked or graded without environmental review under CEQA or even adequate surveys to determine owl presence, and due to the precipitously declining breeding burrowing owl population in Davis, in 2003 Davis enacted a disking ordinance (McNerny and Sears 2007). Prior to 2000, the City had no policies or programs to protect burrowing owls within city limits, and the Davis owl population had declined from more than 40 pairs in 1985 to 16 pairs in 2001 and 14 pairs in 2003 (McNerny and Sears 2007). A temporary disking ordinance enacted in 2000 was replaced with a permanent Disking Ordinance (Davis Municipal Code 8.18.0), which prohibits disking, tilling or grading without City approval and a biological survey, with mitigation and conditions to protect special-status plants and wildlife. As of 2007 the ordinance was successful in preventing direct impacts to burrowing owls on private lands from disking, but was acknowledged as not being an optimal conservation tool, since it does not address direct impacts of loss of foraging habitat, nor does it require off-site mitigation for the loss of owl breeding and foraging habitat (McNerny and Sears 2007). After the implementation of the disking ordinance, the City of Davis had 21 known breeding pairs of owls as of 2007 (YHC 2017), but breeding burrowing owls were completely extirpated from Davis by 2020 (S. Smallwood, pers. comm., 2023), and the ordinance seems to be disregarded.
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Recommended Management and Recovery Actions
This petition has documented significant local and regional extirpations and ongoing dramatic population declines of burrowing owls throughout the majority of their range in California, as well as the failure of current management efforts to reverse this trend. The factors causing burrowing owl declines and the threats to the majority of remaining owl populations can only be addressed by providing elevated legal protection to the species. Without endangered or threatened status, future management policy will continue to emphasize protecting individual owls without fully addressing cumulative habitat loss or other factors reducing survivorship. Ultimately, the protection of the burrowing owl in California hinges on strong habitat protection regulations.
Recommended management and recovery actions for the burrowing owl:
1. List imperiled regional burrowing owl populations or the statewide population under CESA. Listing will allow CDFW to apply effective and meaningful protection measures for breeding owls and for essential owl habitat during the CEQA process.
Listing will also likely result in wider scale coverage of burrowing owls under regional conservation plans such as HCPs and NCCPs.
2. Make CDFW (2012) survey and mitigation guidelines required instead of voluntary.
This will ensure that appropriate breeding-season surveys are completed and strengthen CDFW’s warning that eviction can be interpreted as take.
3. Update CDFW (2012) to require stronger survey methods based on what has been learned from research over the past decade. Require that CDFW’s survey guidelines are implemented rather than other guidelines that appear in HCPs. Update CDFW (2012) to require implementation of mitigation ratios that are incentivized to protect habitat closer to the site of authorized take. Vary mitigation ratios so that they are smaller for habitat protected closer to the site of take, and larger for habitat protected farther from the site of take.
4. Curtail the use of evictions through passive relocation. Passive relocation (eviction) of burrowing owls to allow permanent impacts to burrowing owl breeding pairs or habitat should be considered “take” and not be allowed except in special circumstances; and then only when owls are moved short distances and to permanently protected and managed lands. Appropriate uses of passive relocation would be on public lands such as large military reservations, when used to discourage nesting in proximity to airport runways, or when used to avoid take for temporary disturbances (such as pipelines).
Any relocation of owls should require marking, monitoring, and meeting success criteria.
5. Continue CDFW translocation policy. Translocation, or active relocation of owls should only be allowed for scientific research or under a NCCP conservation strategy.
Any relocation of owls should require marking, monitoring, and meeting success criteria.
Require performance bonds to fund additional measures should translocation not meet success criteria.
6. Accelerated regional conservation planning. CDFW should immediately develop emergency burrowing owl protection and recovery plans for regions where breeding owls are nearing extirpation. This would include the Bay Area, Central Valley, Central Coast, and Southwestern California regions.
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7. Focus on large stable populations on private lands and on gr asslands. Permanent protection of large, stable breeding groups or colonies of owls on unprotected private lands should be the highest priority for acquisition or conservation easements. Most burrowing owls now live at an artificially high population density in a narrow niche on the margins of agricultural lands, and if management practices change slightly, these populations cannot be depended upon to buffer environmental perturbations. Burrowing owls should be reintroduced and their native grassland habitat retained and experimentally restored wherever possible. Restoration using experimental designs is needed to convincingly answer questions about efficacy and which factors contributed most to restoration success.
8. Strengthen mitigation requirements. Robust mitigation should be required for any permanent impacts to breeding owl pairs or habitat. Loss of breeding pairs must be mitigated with equal or greater conservation of breeding pairs or occupied habitat, through permanent acquisition or conservation easement. Mitigation lands must include long-term management, monitoring, and demonstration of breeding colony success. If artificial burrows are used for mitigation, there should be a requirement for maintenance of the burrows and funding for such maintenance in perpetuity.
9. Keep mitigation local or regional. Mitigation requirements and ratios should incentivize offsetting impacts to burrowing owls or habitat by protecting local or regional owl colonies or habitat, to prevent eventual extirpations. The further away from project impacts mitigation lands are located, the higher the mitigation ratio should be.
10. Enforce state fish and game codes. CDFW should bring enforcement actions under Section 681, Title 14 and Fish and Game Code sections 3503 and 3503.5 for documented take of burrowing owls by developers, industrial energy facilities, or counties or cities that authorize illegal take. Enforcement should be a priority for projects or actions that cause massive ongoing take of burrowing owls (such as at Altamont Pass).
11. Prioritize public ownership/conservation management. CDFW should scale back use of for-profit mitigation and conservation banks, and instead prioritize owl conservation banks on public lands or by nonprofit organizations with an interest in maintaining owls in perpetuity.
12. Conduct another statewide breeding owl survey. It has been 16 years since the Institute for Bird Populations resurvey of the entire burrowing owl breeding range in the state from 2006-2007. The state should fund another comprehensive IBP statewide breeding survey, to better evaluate population trends, identify where emergency measures are needed, and inform state policy and recovery planning. Listing the species should NOT be contingent on completing such a survey, since it could take many years, and there is ample information demonstrating population declines and the threatened and endangered status of populations.
13. Statewide recovery plan. CDFW should turn the draft conservation plan into a statewide recovery plan, with a roadmap for curtailing extirpations and declining population trends, and moving regional populations toward recovery.
14. Amend management and land use plans to ensure recovery. County and city general plans should be revised to address the protection and restoration of owl habitat 167
appropriate for their areas, and to be consistent with the CDFW recovery plan.
Environmental impact documents for projects which impact owls must then comply with local planning documents and CDFW requirements. Municipalities must be required to implement statewide burrowing owl recovery guidelines as part of the CEQA and planning process.
15. HCPs and NCCPs. HCPs and NCCPs that cover the burrowing owl should be reviewed to ensure they are not promoting extirpation of burrowing owls and ensure they are assisting recovery. New HCPs and NCCPs should be consistent with a statewide recovery plan. If the burrowing owl is a covered species under an HCP or NCCP, monitoring and active management should be automatically required.
Burrowing Owl Management Impacts on Other Species
Several other wildlife species may benefit from increased protection for burrowing owls in different parts of the burrowing owl's range in California. Increased grassland habitat protection for burrowing owls in Altamont Pass would complement California red-legged frog (Rana draytonii), California tiger salamander (Ambystoma californiense), loggerhead shrike (Lanius ludovicianus), prairie falcon (Falco mexicanus), northern harrier (Circus hudsonius), and white- tailed kite (Elanus leucurus). Increased protection in in the southern San Joaquin Valley would complement conservation efforts for the San Joaquin kit fox (Vulpes macrotis mutica), blunt- nosed leopard lizard (Gambelia sila), various listed and special-status kangaroo rats (Dipodomys ingens, D. nitratoides nitratoides, D. n. exilis, D. n. brevinasus), San Joaquin antelope squirrel (Ammospermophilus nelsoni), San Joaquin pocket mouse (Perognathus inornatus inornatus), and Tulare grasshopper mouse (Onychomys torridus tularensis).
Increased protection of burrowing owls would also benefit golden eagle (Aquila chrysaetos), American kestrel (Falco sparverius), grasshopper sparrow (Ammodramus savannarum), Swainson's hawk (Buteo swainsoni), California horned lark (Otocoris alpestris actia), American badger (Taxidea taxus), and Salinas pocket mouse (Perognathus inornatus psammophilus) in the overlapping portions of their respective ranges. In the Mojave Desert, increased protection of burrowing owls would complement protection of desert tortoise (Xerobates agassizi) and Mohave ground squirrel (Spermophilus mohavensis). The habitat of the endangered Delhi Sands Flower Loving Fly (Rhaphiomidas terminatus abdominalis) in Colton, Fontana and Mira Loma overlaps with probable burrowing owl habitat.
Management and recovery of burrowing owls is not expected to have significantly negative impacts on other wildlife species. Increased owl numbers could impact local populations or concentrations of some prey species. Burrowing owls have been known to prey on California least terns (Sterna antillarum brownii), a federally endangered species, at colonies on North Island and Ream Field (Imperial Beach) in San Diego County. Owls are hazed away from tern nests at Ocean Beach and also discouraged in the vicinity of snowy plover (Charadrius alexandrinus nivosus) nesting areas in the region.
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Individuals with Burrowing Owl Expertise Supporting Petitioned Action
Chris Alford
Principal, Alford Environmental
Scott Artis, MA
Founder and Executive Director, Urban Bird Foundation and Burrowing Owl Conservation Network
John H. Barclay
Albion Environmental (retired)
Daniel S. Cooper, Ph.D.
Resource Conservation District of the Santa Monica Mountains
Jim Estep
Wildlife Biologist
Lisa Henderson
Director of Biological Services, Olberding Environmental, Inc., San Ramon, CA
Dr. Geoffrey L. Holroyd
Research Scientist (retired), Canadian Wildlife Service, Environment and Climate Change Canada
Adjunct Professor (retired), University of Alberta
Chair, Beaverhill Bird Observatory
Robin D. Ikeda
Biology Professor Emerita, Chaffey College
David H. Johnson
Director, Global Owl Project
Jeff W. Kidd
Raptor Biologist, Vice President, Kidd Biological, Inc.
Sandra Menzel
Senior Wildlife Biologist
Anthony Metcalf, Ph.D.
Professor of Biology, California State University, San Bernardino
Ryan Phillips
Raptor Biologist
Catherine Portman
CEO & Co-founder, Burrowing Owl Preservation Society, Woodland, CA
K. Shawn Smallwood, Ph.D.
Ecologist
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Carl Thelander
President/CEO BioResource Consultants, Inc.
Dr. Lynne Trulio
Professor, Department of Environmental Studies, San Jose State University
Dr. J.H. Widdicombe
Professor of Physiology, U.C. Davis
Bob Wilkerson
Staff Biologist, Institute for Bird Populations
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Bibliography of Literature Cited
Abbott, C.G. 1930a. Urban Burrowing Owls. Auk. Vol. XLVII, No. 4, October 1930, pp. 564-565.
Abbott, C.G. 1930b. Owl Voices. Condor. Volume XXXII, Number 5, September-October 1930, p. 258.
AECOM. 2012. IID Burrowing Owl Monitoring Results 2012. Presentation, September 21, 2012.
Ahmed, Q. 2022. Use of a Utility-Scale Solar Energy Facility by Avian Populations in Central California. Master’s Thesis, San Jose State University.
Albion Environmental, Inc. 2008. Camp Parks Reserve Forces Training Area Burrowing Owl Management Plan. Prepared For: U.S. Army Combat Support Training Center, Environmental Division. Fort Hunter Liggett, CA. Prepared by J. Barclay.
Albion Environmental, Inc. 2010. Camp Parks Reserve Forces Training Area 2009 Burrowing Owl Survey Report.
Albion Environmental, Inc. 2011. Camp Parks Reserve Forces Training Area 2010 Burrowing Owl Survey Report.
Albion Environmental, Inc. 2012. Camp Parks Reserve Forces Training Area 2011 Burrowing Owl Survey Report.
Albion Environmental, Inc. 2022. 2022 Annual Burrowing Owl Breeding Season Census at Sharpe Depot. Unpublished report, December 2022. 26 pp.
Althouse & Meade Biological And Environmental Services, Inc. 2009-2018. Palo Prieto Conservation Bank 2009-2018 Annual Reports.
Althouse & Meade Biological And Environmental Services, Inc. 2011. Habitat Mitigation and Monitoring Plan Resource Management Plan for the Topaz Solar Farm Conservation Lands, San Luis Obispo County, California. Prepared for Topaz Solar Farms, LLC.
Althouse & Meade Biological And Environmental Services, Inc. 2012-2013. Topaz Solar Farm Conservation Lands Habitat Mitigation and Monitoring Plan, 2012-2013 Annual Report.
American Museum of Natural History (AMNH). 2001. Collection data provided by Paul Sweet, Collections Manager, Department of Ornithology, American Museum of Natural History, New York.
American Ornithologists’ Union (AOU). 1983. Check-List of North American Birds. 6th edition.
Washington, D.C.
American Ornithologists’ Union (AOU). 1991. Thirty-Eighth Supplement to the American Ornithologists’ Union Check-List of North American Birds. Auk 108: 750-754.
American Ornithologists’ Union (AOU). 1997. Forty-First Supplement to the Check-List of North American Birds. Auk 114(3): 542-552.
171
Anderson, J.W. 1979. The Burrowing Owl in Sacramento. Bulletin, Sacramento Zoological.
Society. Vol. 16, No. 1 (from a scientific paper presented at the 1977 annual meeting of the American Ornithologists' Union, Berkeley, CA).
Anderson, S.H., L.W. Ayers, J.A. Dechant, M.T. Green, W.H. Howe, S.L. Jones, D.S. Klute, D.K. Rosenberg, S.R. Sheffield, and T.S. Zimmermann. 2001. Draft Status Assessment and Conservation Plan for the Western Burrowing Owl in the United States. Administrative Report.
U.S. Department of the Interior, Fish and Wildlife Service, Denver, Colorado.
Animal Damage Control (ADC). 1993. National Annual Report for Fiscal Year 1993. U.S.
Department of Agriculture.
Animal Damage Control (ADC). 1994. National Annual Report for Fiscal Year 1994. U.S.
Department of Agriculture.
Animal Damage Control (ADC). 1995. National Annual Report for Fiscal Year 1995. U.S.
Department of Agriculture.
Arbib, R. 1976. Blue List for 1977. American Birds. Volume 30, No. 6, pp. 1031-1039.
Arizona Game and Fish Department (AGFD). 1995. Status Designations Notebook. Heritage Data Management System. Phoenix, Arizona.
Association of Bay Area Governments (ABAG). 1999. Projections 2000. Forecasts for the San Francisco Bay Area to 2020 and Beyond.
Audubon California. 2015. An Interactive Mapping Tool for Burrowing Owl Conservation in Imperial Valley, California. Prepared for: Imperial Valley Community Foundation.
Audubon Society. 2019. Survival by Degrees: 389 Bird Species on the Brink.
Bailey, F.M. 1917. Red Letter Days in Southern California. Condor. Volume XIX, Number 5, September-October 1917, p. 158.
Baird, S.F. 1870. Ornithology. Volume I. Land Birds. Geological Survey of California. Edited by S. F. Baird, from the manuscript and notes of J. G. Cooper.
Barclay, J. 2007. Burrowing Owl Management at Mineta San Jose International Airport. Pages 146-154 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Barclay, J. and R. Cull. 1999. Northeastern California Burrowing Owl Population Estimate.
Unpublished report, 15 pp.
Barclay, J.H. and S. Menzel. 2011. Apparent Polygynous Nesting by Burrowing Owls. Journal of Raptor Research 45(1), pp.98-100.
Barclay, J., C. Bean, D. Plumpton, B. Walton, and the California Burrowing Owl Consortium. 1998. Burrowing Owl Conservation in California: Issues and Challenges. Page 7 in Abstracts of the Second International Burrowing Owl Symposium, Ogden, Utah.
172
Barclay, J.H., N.M. Korfanta and M. Kauffman. 2011. Long-Term Population Dynamics of a Managed Burrowing Owl Colony. Journal of Wildlife Management 75(6):1295-1306.
Baril, A. 1993. Pesticides and Wildlife in the Prairies: Current Regulatory Issues. Pages 44-48 in G.L. Holyrod, H.L. Dickson, M. Regnier, and H.C. Smith (editors). Proceedings of the Third Endangered Species and Prairie Conservation Workshop. Natural History Occasional Paper 19.
Provincial Museum of Alberta, Edmonton, Alberta.
Barlow, C. 1901. A List of the Land Birds of the Placerville - Lake Tahoe Stage Road. Condor.
Volume 3, Number 6, November-December 1901, p. 162.
Barr, K.R. 2021. Expanding Genomics Toolkits to Facilitate the Conservation and Recovery of Two Protected Species, the Tricolored Blackbird and Burrowing Owl. Ph.D. dissertation, University of California, Los Angeles.
Barr, K., C. Bossu, R. Bay, E. Anderson, J. Belthoff, L. Trulio, D. Chromczak, C. Wisinski, T.
Smith and K. Ruegg. 2023. Genetic and Environmental Drivers of Migratory Behavior in Western Burrowing Owls and Implications for Conservation and Management. Evolutionary Applications 00:1–12.
Barrentine, C.D. and K.D. Ewing. 1988. A Capture Technique for Burrowing Owls. North American Bird Bander, Oct.-Dec. 1988, p. 107.
Bartholomew, P.S. 1940. Bird Life in the Gibraltar Study Area. U.S. Forest Service Publication, Los Padres National Forest, California.
Bartok, N.D. and C.J. Conway. 2010. Factors Affecting the Presence of Nesting Burrowing Owls in an Agricultural Landscape. Journal of Raptor Research, 44(4): 286-293.
Beedy, E.C. and S.L. Granholm. 1985. Discovering Sierra Birds. Western Slope. Yosemite Natural History Association and Sequoia Natural History Association.
Bell, C., W. Acevedo, and J.T. Buchanan. 1994. Dynamic Mapping of Urban Regions: Growth of the San Francisco Sacramento Region. In Proceedings, 3rd annual urban and regional information systems association conference; 1995 July 16-20; San Antonio, Texas: 723-734.
Bellocq, M.l. 1997. Ecology of the Burrowing Owl in Agroecosystems of Central Argentina.
Pages 52-57 in J.L. Lincer and K. Steenhof [eds.] The Burrowing Owl, its Biology and Management: Including the Proceedings of the First International Symposium. Raptor Research Report No. 9.
Belthoff, J.R. and R.A. King. 2002. Nest-Site Characteristics of Burrowing Owls in the Snake River Birds of Prey National Conservation Area, Idaho, and Applications to Artificial Burrow Installation. Western North American Naturalist 62:112-119.
Belthoff, J.R. and B.W. Smith. 2003. Patterns of Artificial Burrow Occupancy and Reuse by Burrowing Owls in Idaho. Wildlife Society Bulletin 31:138–144.
Bendix, J.A. 2007. Passive Relocation of Burrowing Owls on a 57-Hecatre Site in Eastern Alameda County. Pages 141-145 in Proceedings of the California Burrowing Owl Symposium, 173
November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Bent, A.C. 1938. Life Histories of North American Birds of Prey. Part 2. Smithsonian Institution, U.S. National Museum Bulletin 170. Washington, D.C.
Berner, M. 2015. Solano County Breeding Bird Atlas.
Berry, K.H. 1973. Birds of the Desert Tortoise Preserve. Unpublished list prepared for the Desert Tortoise Preserve Committee.
Biosearch Associates. 2014-2016. Biological Monitoring Reports (2013-2016), Vasco Winds Ecological Preserve, Contra Costa County, California. Prepared for California Rangeland Trust .
Biosearch Environmental Consulting. 2018-2019. Annual Monitoring and Management Reports (2017-2018), Sparling Ranch Conservation Bank, San Benito and Santa Clara Counties, California.
Biosearch Wildlife Surveys (BWS). 1991. Mohave Ground Squirrel study at El Mirage Cooperative Management Area. Report prepared for the U.S. Bureau of Land Management, California Desert District Office, Riverside, CA. Contract #B950C10026.
BioSystems Analysis, Inc. 1993a. Biological Resource Surveys for the Proposed Tuscarora Natural Gas Pipeline Project. Prepared for Tuscarora Gas Transmission Company, Reno, NV.
BioSystems Analysis Inc., Santa Cruz, CA. Unpublished Report.
BioSystems Analysis, Inc. 1993b. Reno-Alturas Transmission Project, 1993 Resource Reconnaissance Surveys. Prepared for Sierra Pacific Power Company, Reno, NV. BioSystems Analysis Inc., Santa Cruz, CA. Unpublished Report.
BioSystems Analysis, Inc. 1994. Special Status Terrestrial Wildlife Surveys, Tuscarora Pipeline Project. Prepared for Tuscarora Gas Transmission Company, Reno, NV. BioSystems Analysis Inc., Santa Cruz, CA. Unpublished Report.
BioSystems Analysis, Inc. 1995. Tuscarora Gas Transmission Project: Botanical and Wildlife Resource Survey. Prepared for Tuscarora Gas Transmission Company, Reno, NV. BioSystems Analysis Inc., Santa Cruz, CA. Unpublished Report.
Bird Banding Laboratory (BBL). 2023. Longevity Records of North American Birds. Version 2023.1. Eastern Ecological Science Center. US Geological Survey. Laurel, MD. From BBL Banding Portal, accessed 2/27/24.
Bloom Biological, Inc. 2009. Burrowing Owl Population Size in the Imperial Valley, California:
Surveys and Sampling Methodologies for Estimation. Final report to the Imperial Irrigation District, Imperial, California, April 15, 2009.
Bloom, P.H. 2023. Extirpation of Orange County, California, Breeding Burrowing Owl Population: The Convergence of Philopatry, Habitat Fragmentation, and Allee Effects. Journal of Raptor Research 57 (3): 475–484.
174
Boatman, N.D., Brickle, N.W., Hart, J.D., Milsom, T.P., Morris, A.J., Murray, A.W.A., Murray, K.A., and Robertson, P.A. 2004. Evidence for the Indirect Effects of Pesticides on Farmland Birds. Ibis (London, England), 146(s2), 131–143. https://doi.org/10.1111/j.1474- 919X.2004.00347.x
Bock, C.E., V.A. Saab, T.D. Rich, and D.S. Dobkin. 1992. Effects of Livestock Grazing on Neotropical Migratory Landbirds in Western North America. In status and management of neotropical migratory birds. USDA, USFS - General Technical Report RM-229.
Boersma, P.D., P. Kareiva, W.F. Fagan, J.A. Clark and J.M. Hoekstra. 2001. How Good are Endangered Species Recovery Plans? BioScience 51: 643–649.
Bolander, G.L. and B.D. Parmeter. 1978. Birds of Sonoma County, California: An Annotated Checklist and Birding Gazetteer. Grape Press Printing, Napa, California.
Bond, R.M. 1939. Observations on Raptorial Birds in the Lava Beds-Tule Lake Region of Northern California. Condor. Volume XLI, Number 2, March-April 1939, p. 55.
Bond, R.M. 1942. Food of the Burrowing Owl in Western Nevada. Condor 44: 183.
Botelho, E.S. 1996. Behavioral Ecology and Parental Care of Breeding Western Burrowing Owls (Speotyto cunicularia hypugaea) in Southern New Mexico, USA. Dissertation, New Mexico State University, Las Cruces, New Mexico.
Botelho, E.S. and P.C. Arrowood. 1996. Nesting Success of Western Burrowing Owls in Natural and Human-Altered Environments. Pages 61-68 in Raptors in Human Landscapes. Academic Press Inc.
Botelho, E.S. and P.C. Arrowood. 1998. The Effect of Burrow Site Use on the Reproductive Success of a Partially Migratory Population of Western Burrowing Owls (Speotyto cunicularia hypugaea). Journal of Raptor Research 32:233-240.
Bowman, R.I. 1961. Late Spring Observations on Birds of South Farallon Island, California.
Condor. Volume 63, Number 5, September-October 1961, p. 414.
Brattstrom, B.H. 1995. Wildlife Mortalities in PVC Claim Posts. Wildlife Society Bulletin 23(4):
765-766.
Breninger, G.F. 1904. San Clemente Island and Its Birds. Auk. Vol. XXI, No. 2, April 1904, p. 222.
Brenkle, J.F. 1936. The Migration of the Western Burrowing Owl. Bird Banding 7: 66-68.
Breon, C. 2009. Losing What We Thought We Gained: An Investigation into Mitigation Monitoring. Prepared for the Santa Clara Valley Audubon Society.
Breon, C. 2015. Issues with Mitigation Banks – How to Make Them Work for Burrowing Owls.
California Burrowing Owl Consortium Conference, 2015.
Brown, N.L. and R.W. Mannan. 2002. Status of Burrowing Owls in Arizona. Final Report.
Prepared for the Arizona Game and Fish Department.
175
Bryant, W.E. 1888. Proceedings of the California Academy of Sciences, 2nd Series, Volume I, 1888, p. 45.
Buchanan, J.T. 1996. A Spatial Analysis of the Burrowing Owl (Speotyto cunicularia hypugaea) Population in Santa Clara County, California Using A Geographic Information System. M.S.
Thesis. Department of Environmental Studies, San Jose State University.
Buchanan, J.T. 1997. A Spatial Analysis of the Burrowing Owl (Speotyto cunicularia) Population in Santa Clara County, California Using A Geographic Information System. Pages 90-96 in J.R.
Duncan, D.H. Johnson, and T.H. Nichols (editors). Biology and Conservation of Owls of the Northern Hemisphere. USDA Forest Service, General Technical Report NC-190. North Central Forest Experiment Station, St. Paul, Minnesota.
Burkett, E.E. and B.S. Johnson. 2007. Development of A Conservation Strategy for Burrowing Owls in California. Pages 165-168 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Burridge, B. 1995. Sonoma County Breeding Bird Atlas. Madrone Audubon Society.
Burrowing Owl Preservation Society (BOPS). 2015. California Burrowing Owl Consortium Conference Presentation Summaries. October 24, 2015.
Burrowing Owl Preservation Society (BOPS). 2023. Yolo County Burrowing Owl Survey 2023.
Butts, K.O. 1973.Observations on the Ecology of Burrowing Owls in Western Oklahoma. A Preliminary Report. Proceedings of the Oklahoma Academy of Science 51: 66-74.
California Academy of Sciences (CAS). 2002a. California Academy of Sciences Ornithology Holdings.
California Academy of Sciences (CAS). 2002b. California Academy of Sciences Photo Collection. www.calacademy.org
California Burrowing Owl Consortium (CBOC). 1997. Burrowing Owl Survey Protocol and Mitigation Guidelines. Appendix B. Pages 171-177 in Lincer, J.L. and K. Steenhof (editors). 1997. The Burrowing Owl, its Biology and Management; Including the Proceedings of the First International Burrowing Owl Symposium. Raptor Research Report Number 9.
California Climate and Agriculture Network (CCAN). 2023. Farmland Conservation. https://calclimateag.org/solutions/farmlandconservation/
California Department of Conservation (CDOC). 1994. California Farmland Conversion Report 1990-1992. Farmland Mapping and Monitoring Program, Division of Land Resource Protection.
California Department of Conservation (CDOC). 2000. California Farmland Conversion Report 1996-1998. Farmland Mapping and Monitoring Program, Division of Land Resource Protection.
California Department of Corrections (CDC). 1999. Statewide Electrified Fence Project Habitat Conservation Plan. Prepared by EDAW.
176
California Department of Finance (CDF). 2020a. Historical Census Populations of Counties and Incorporated Cities in California, 1850–2020. https://dof.ca.gov/reports/demographic-reports/
California Department of Finance (CDF). 2020b. County Population Projections (2020-2060). https://dof.ca.gov/forecasting/demographics/projections/
California Department of Fish and Game (CDFG). 1975. Arroyo de las Coches and Silver Creek Stream Surveys. From CDFG files, Yountville, California.
California Department of Fish and Game (CDFG). 1990. Wildlife Habitat Relationships System Database.
California Department of Fish and Game (CDFG). 1994. Burrowing Owl Draft Mitigation Guidelines. Unpublished report.
California Department of Fish and Game (CDFG). 1995. Staff Report on Burrowing Owl Mitigation. Unpublished report. 8 pp.
California Department of Fish and Game (CDFG). 2002a. Information from CDFG files on the burrowing owl provided by David Kiene, Office of the General Counsel, CDFG.
California Department of Fish and Game (CDFG). 2002b. Conservation and Mitigation Banking.
Habitat Conservation Planning Branch.
California Department of Fish and Game (CDFG). 2003a. Petition Evaluation for Western Burrowing Owl (Athene cunicularia hypugaea). October 2003
California Department of Fish and Game (CDFG). 2003b. Petition Evaluation for Western Burrowing Owl (Athene cunicularia hypugaea). August 2003
California Department of Fish and Game (CDFG). 2008. Monitoring Burrowing Owl Populations at Yolo Bypass Wildlife Area and Wildhorse Golfcourse, Yolo County, California, 2008. Report by Zach Smith and Chris Stermer, CDFG Sacramento Office.
California Department of Fish and Game (CDFG). 2012. Staff Report on Burrowing Owl Mitigation. State of California, Natural Resources Agency, Department of Fish and Game.
Replaced the 1995 Staff Report on Burrowing Owl Mitigation.
California Department of Fish and Wildlife (CDFW). 2015-2020. Topaz Solar Farm Conservation Lands Habitat Mitigation and Monitoring Plan, 2014-2019 Annual Reports, North Carrizo Ecological Reserve.
California Department of Fish and Wildlife (CDFW). 2018. Alkali Sink Conservation Bank Annual Report 2017-2018.
California Department of Fish and Wildlife (CDFW). 2019. Public Draft Land Management Plan for the Carrizo Plains Ecological Reserve. Prepared by Jodi McGraw Consulting for California Department of Fish and Wildlife.
177
California Department of Fish and Wildlife (CDFW). 2022a. May 20, 2022 comment letter on The Greentree Project (File No. 16-289), Draft Environmental Impact Report, SCH No. 2019049003, City of Vacaville, Solano County.
California Department of Fish and Wildlife (CDFW). 2022b. March 2022 Status Review of Western Joshua Tree (Yucca brevifolia).
California Department of Fish and Wildlife (CDFW). 2023a. Conservation and Mitigation Banks Established in California by CDFW.
https://wildlife.ca.gov/Conservation/Planning/Banking/Approved-Banks
California Department of Fish and Wildlife (CDFW). 2023b. California Conservation and Mitigation Banking. Report to the Legislature.
California Department of Fish and Wildlife (CDFW). 2023c. Conservation Plans by Species. https://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=108719&inline
California Department of Fish and Wildlife (CDFW). 2024. Status Review for Mojave Desert Tortoise (Gopherus agassizii). Report to the California Fish and Game Commission.
California Department of Pesticide Regulation (CDPR). 2001. 1990-1999 Pesticide Use Reporting. www.cdpr.ca.gov
California Department of Pesticide Regulation (CDPR). 2023a. Pesticide Use Reporting 2019- 2021 Summary Data. ww.cdpr.ca.gov
California Department of Pesticide Regulation (CDPR). 2023b. Chlorpyrifos, Active Ingredients database output. https://apps.cdpr.ca.gov/cgi-bin/label/labq.pl?p_chem=253&activeonly=on (last visited December 2023)
California Energy Commission (CEC), California Department of Fish and Wildlife, U.S. Bureau of Land Management, and U.S. Fish and Wildlife Service. 2016. California Desert Biological Conservation Framework.
California Environmental Resources Evaluation System (CERES). 2002. The Catalogue of Conservation Banks in California. ceres.ca.gov/topic/banking/catalogue_index.html
California Natural Diversity Database (CNDDB). 2001. CNDDB Burrowing Owl Records as of 2001. California Department of Fish and Game.
California State University, Chico (CSUC). 2001. Collection data provided by Jay Bogiatto, Department of Biology, California State University, Chico.
California State University, Long Beach (CSULB). 2001. Ornithology collection data provided by Charlie Collins, California State University, Long Beach.
Campbell, K. 1999. Burrowing Owl, Athene cunicularia. In West Mojave Habitat Conservation Plan Species Accounts: Birds. U.S. Bureau of Land Management, California Desert District.
Canfield, C.S. 1869. Habits of the Burrowing Owl of California. American Naturalist, Volume 2, Issue 11: 583-586.
178
Captanian, N., M.G. Hawkins, C. Fiorello, M. Thurber and W. K. Reisen. 2017. Low Prevalence of West Nile Virus Antibodies in Select Northern California Owl Species (2007–2014). Journal of Zoo and Wildlife Medicine 48(4).
Carnegie Museum of Natural History (CMNH). 2002. Collection data provided by Robin Panza, Section of Birds, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania.
Carter, F. 1937. Minutes of Cooper Club Meetings. Condor. Volume XXXIX, Number 3, May- June 1937, p. 136.
Catalina Island Conservancy (CIC). 2002. Island Ecology. www.catalinaconservancy.org
Catlin, D.H. 2004. Factors Affecting Within Season and Between Season Breeding Dispersal of Burrowing Owls in California. M.S. Thesis, Oregon State University, Corvallis, Oregon, USA.
Catlin, D.H. and D.K. Rosenberg. 2006. Nest Destruction Associated with Mortality and Dispersal of Burrowing Owls in the Imperial Valley, California. The Southwestern Naturalist 51(3): 406-409.
Catlin, D.H. and D.K. Rosenberg. 2014. Association of Sex, Fledging Date, and Sibling Relationships with Post-Fledging Movements of Burrowing Owls in a Nonmigratory Population in the Imperial Valley, California. Journal of Raptor Research 48(2):106–117.
Center for Biological Diversity (CBD), Santa Clara Valley Audubon Society, Defenders of Wildlife, San Bernardino Valley Audubon Society, California State Park Rangers Association, and Tri-County Conservation League. 2003. Petition to List the California Population of the Western Burrowing Owl (Athene cunicularia hypugaea) as an Endangered or Threatened Species Under the California Endangered Species Act. Submitted to State of California Fish and Game Commission.
Center for Environmental Management of Military Lands (CEMML). 2018. Parks Reserve Forces Training Area 2017 Annual Burrowing Owl Survey Report, Alameda and Contra Costa Counties, California. March 2018.
Center for Natural Lands Management (CNLM). 2016. Revised Property Analysis Record for Perpetual Stewardship Responsibilities on the ~ 441-acre Lost Hills Preserve, Kern County, California (PN280).
Center for Natural Lands Management (CNLM). 2023. Our Preserves. www.cnlm.org
Centers for Disease Control and Prevention (CDC). 2002. West Nile Virus; West Nile Virus and Birds. U.S. Dept. of Health and Human Services, Division of Vector-Borne Infectious Diseases. www.cdc.gov/ncidod/dvbid/westnile/qa/wnv_birds.htm
CH2MHILL. 2001. Draft Habitat Conservation Plan, Imperial Irrigation District Water Conservation and Transfer Project.
Chan, F. 2001. Vegetation Management Plan for the Wildhorse Ag Buffer. Unpublished consultant report for the City of Davis Open Space Program.
179
Chandler, S., Tietz, J., Bradley, R. and L. Trulio. 2016. Burrowing Owl Diet at a Migratory Stopover Site and Wintering Ground on Southeast Farallon Island, California. Journal of Raptor Research. 50. 391-403. 10.3356/JRR-16-00006.1.
Chicago Academy of Sciences (CHAS). 2001. Collection data provided by Steven Sullivan, Collections Manager, Chicago Academy of Sciences, Chicago. Illinois.
Chromczak, D. 2002. South San Francisco Bay Burrowing Owl Demography Study: Annual Progress Reports, 1998-2001. Unpublished data provided by personal communication, 2002.
City of Sacramento, Sutter County, and Natomas Basin Conservancy. 2003. Final Natomas Basin Habitat Conservation Plan.
Clark, R.J., J.L. Lincer, and J.S. Clark. 1994. A Bibliography on the Burrowing Owl (Athene cunicularia). Department of Biology, York College of Pennsylvania, York, PA. 51 pp.
Clark, R.J., D.G. Smith, and L.H. Kelso. 1978. Working Bibliography of Owls of the World.
National Wildlife Federation Scientific Technical Series, No. 1. Washington, D.C.
Clayton, K.M. and J.K. Schmutz. 1997. Burrowing Owl (Speotyto cunicularia) Survival in Prairie Canada. Pages 107-110 in Duncan, J.R., D.H. Johnson and T.H. Nicholls (editors). Biology and Conservation of Owls of the Northern Hemisphere: 2nd International Symposium, Winnipeg, Manitoba, Canada. General Technical Report NC-190. USDA Forest Service, North Central Forest Experimental Station, St. Paul, Minnesota.
Clemings, R. 1996. Mirage: The False Promise of Desert Agriculture. Sierra Club Books, San Francisco, California.
Coachella Valley Association of Governments (CVAG). 2001. Coachella Valley Multiple Species Habitat Conservation Plan.
Coachella Valley Conservation Commission (CVCC). 2007. Final Recirculated Coachella Valley Multiple Species Habitat Conservation Plan and Natural Community Conservation Plan, September 2007. https://cvmshcp.org/plan-documents/
Collins, C.T. 1979. The Ecology and Conservation of Burrowing Owls. Pages 6-17 in Scheaffer, P.P. and S.M. Ehlers (editors), Proceedings of the National Audubon Society Symposium of Owls of the West, Their Ecology and Conservation. National Audubon Society Western Education Center, Tiburon, CA.
Collins, C.T. and R.E. Landry. 1977. Artificial Nest Burrows for Burrowing Owls. North American Bird Bander 2:151-154.
Conard, C. 2023. Burrowing Owls Over the Last 25 Years in Sacramento County: An Unsteady Decline. Sacramento Wastewater Treatment Plant Bufferlands. 2023 Burrowing Owl Symposium, February 6-7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws-west.org/2023buowsymposium/abstracts?authuser=0
Conard, C. 2024. Precipitous Decline of Burrowing Owls in the Sacramento Area. Central Valley Birds. In prep. for Vol 27 (2024).
180
Conroy, R.M. and D.L. Chesemore. 1987. Food Habits of the Burrowing Owl (Athene cunicularia) in Fresno County, California. Pp. 105-110 in D.F. Williams, S. Byrne, and T.A. Rado (editors). Endangered and Sensitive Species of the San Joaquin Valley, California: Their Biology, Management, and Conservation. California Energy Commission, Sacramento, California.
Conway, C.J. 2018. Spatial and Temporal Patterns in Population Trends and Burrow Usage of Burrowing Owls in North America. Journal of Raptor Research 52:129–142.
Corvus Ecological Consulting. 2015. Gabrych (BRP) Study Area Survey Results, General Habitat and Sensitive Species Suitability Assessment.
Corvus Ecological Consulting. 2017. Black Mountain Conservation Bank Internal Summary/Survey Results: General Habitat and Sensitive Species Suitability Assessment.
Corvus Ecological Consulting. 2018. Alta Oak Creek Mojave Mitigation Conservation Areas (AOCMCA) 2017 Annual Report.
Coulombe, H.N. 1971. Behavior and Population Ecology of the Burrowing Owl, Speotyto cunicularia, in the Imperial Valley of California. Condor. Volume 73, Number 2, Summer 1971, pp. 162-176.
County of Sacramento, City of Rancho Cordova, City of Galt, Sacramento County Water Agency, Sacramento Regional County Sanitation District, and the Southeast Connector Joint Powers Authority. 2018. Final South Sacramento Habitat Conservation Plan. January 2018.
Sacramento, CA.
Cribbs and Associates. 2011-2023. Metro Air Park Habitat Conservation Plan Implementation 2010-2022 Annual Reports. Prepared for Metro Air Park Property Owners Association.
Crowe, D.E. and K.M. Longshore. 2010. Estimates of Density, Detection Probability, and Factors Influencing Detection of Burrowing Owls in the Mojave Desert. Journal of Raptor Research 44(1) : 1-11.
Cull, R.l. and F. Hall. 2007. Status of Burrowing Owls in Northeastern California. Pages 42-51 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Daggett, F.S. 1904. Annual Outing Meeting of the Southern Division, 1903. Condor. Volume VI, Number 1, January-February 1904, p. 22.
Davies, K. 2015. Burrowing Owl Habitat Management at San Jose-Santa Clara Regional Wastewater Facility. California Burrowing Owl Consortium Conference, October, 2015.
Dawson, W.L. 1911. Another Fortnight on the Farallones. Condor. Volume XIII, November 1911, p. 180.
Dawson, W.L. 1923. The Birds of California. Volume Two. South Moulton Company, San Diego, Los Angeles, San Francisco.
181
Dechant, J.A., M.L. Sondreal, D.H. Johnson, L.D. Igl, C.M. Goldade, P.A. Rabie, and B.R.
Euliss. 1999 (revised 2001). Effects of Management Practices on Grassland Birds: Burrowing Owl. Northern Prairie Wildlife Research Center, Jamestown, North Dakota.
Delaware Museum of Natural History (DMNH). 2001. Collection data provided by Gene Hess, Collection Manager – Birds. Delaware Museum of Natural History, Wilmington, Delaware.
Delevoryas, P. 1997. Relocation of Burrowing Owls During Courtship Period. Pages 138-144 in Lincer, J.L. and K. Steenhof (editors). 1997. The Burrowing Owl, Its Biology and Management; Including the Proceedings of the First International Burrowing Owl Symposium. Raptor Research Report Number 9.
DeMay, I. 1942. An Avifauna from Indian Kitchen Middens at Buena Vista Lake, California.
Condor. Volume 44, Number 5, September-October 1942, pp. 228-230.
DeSante, D.F. and D.G. Ainley. 1980. The Avifauna of the South Farallon Islands, California.
Studies in Avian Biology No. 4. Cooper Ornithological Society.
DeSante, D.F. and E. Ruhlen. 1995. A Census of Burrowing Owls in California, 1991-1993.
Institute for Bird Populations. Point Reyes Station, CA.
DeSante, D.F., E.D. Ruhlen, S.L. Adamany, K.M. Burton, and S. Amin. 1997. A Census of Burrowing Owls in Central California in 1991. Pages 38-48 in Lincer, J.L. and K. Steenhof (editors). 1997. The Burrowing Owl, Its Biology and Management; Including the Proceedings of the First International Burrowing Owl Symposium. Raptor Research Report Number 9.
DeSante, D.F., E. Ruhlen, and D.K. Rosenberg. 1996. The Distribution and Relative Abundance of Burrowing Owls in California: Evidence for A Declining Population. Institute for Bird Populations. Point Reyes Station, California.
DeSante, D.F., E.D. Ruhlen, and D.K. Rosenberg. 2004. Density and Abundance of Burrowing Owls in the Agricultural Matrix of the Imperial Valley, California. Studies in Avian Biology No. 27, pp. 116-119.
DeSante, D.F., E.D. Ruhlen, and D.K. Rosenberg. 2007a. Density and Abundance of Burrowing Owls in the Agricultural Matrix of the Imperial Valley, California. Pages 103-108 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
DeSante, D.F., E.D. Ruhlen, and R. Scalf. 2007b. The Distribution and Relative Abundance of Burrowing Owls in California During 1991-1993: Evidence for a Declining Population and Thoughts on its Conservation. Pages 1-41 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
DeSmet, K. 1997. Return Rates and Movements of Burrowing Owls in Southwestern Manitoba (abstract). In Second International Symposium: Biology and Conservation of Owls of the Northern Hemisphere. February 5-9 1997; Winnipeg, Manitoba.
Desmond, M.J. 1991. Ecological Aspects of Burrowing Owl Nesting Strategies in the Nebraska Panhandle. M.S. thesis. University of Nebraska, Lincoln, NB. 114 pp. 182
Desmond, M.J., J.A. Savidge and K M. Eskridge. 2000. Correlations Between Burrowing Owl and Prairie Dog Declines: A 7-Year Analysis. Journal of Wildlife Management 64: 1067-1075.
Desmond, M.J., T.J. Parsons, T.O. Powers and J.A. Savidge. 2001. An Initial Examination Of Mitochondrial DNA Structure in Burrowing Owl Populations. Journal of Raptor Research, 35(4), 274–281.
Desmond, M.J., D. Doublet, D.H. Johnson and F.A. Gebreselassie. 2023. Effects of Group Translocation on Burrowing Owl Survival, Fidelity and Nesting in Arizona. Department of Fish, Wildlife & Conservation Ecology, New Mexico State University and Global Owl Project. 2023 Burrowing Owl Symposium, February 6-7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws-west.org/2023buowsymposium/abstracts?authuser=0
Diamond, J. 1969. Avifauna Equilibria and Species Turnover Rates on the Channel Islands of California. Proceedings of the National Academy of Sciences 64: 57-63.
Dixon, J. 1906. Land Birds of San Onofre, California. Condor. Volume VII, Number 4, July- August 1906, p. 96.
Dixon, J.S. 1933. Field Notes. Manuscript. Cited in USNPS, Check-List of the Birds of the National Parks. Department of the Interior, Washington, D.C. 1937.
Doublet, D. 2020. Effects of Mitigation Translocation on Burrowing Owl Survival, Fidelity, and Reproduction in Arizona. M.S., New Mexico State University.
Doublet, D.D., F. Abadi, D.H. Johnson, and M.J. Desmond. 2022. Survival and Fidelity of Translocated and Resident Burrowing Owls in Arizona. Journal of Wildlife Management.
Drost, C.A. and R.C. McCluskey. 1992. Extirpation of Alternative Prey During A Small Rodent Crash. Oecologia 92: 301-304.
Drury, A. 1953. Point Lobos Reserve State Park, California. Interpretation of a Primitive Landscape. State of California, Division of Beaches and Parks, Department of Natural Resources. Sacramento, California.
Dudek and Associates. 2002. Draft Multi-Species Habitat Conservation Plan, Volume IV, Draft EIR/EIS. Western Riverside County MSHCP. Prepared for the County of Riverside and U.S.
Fish and Wildlife Service.
Dusek, R.J., W.M. Iko and E.K. Hofmeister. 2010. Occurrence of West Nile Virus Infection in Raptors at the Salton Sea, California. Journal of Wildlife Diseases, 46(3), pp. 889–895.
Dyer, O. 1988. Reintroductions of Burrowing Owls (Athene cunicularia) to the South Okanagan Valley, British Columbia (1983-1988). Report to the Ministry of Environment, British Columbia. 7 pp.
Earhart, C.M. and N.K. Johnson. 1970. Size Dimorphism and Food Habits of North American Owls. Condor 72: 251-264.
East Bay Municipal Utility District (EBMUD). 2001. Raptor Surveys. 183
East Contra Costa County Habitat Conservancy (ECCCHC). 2022. East Contra Costa County Habitat Conservation Plan/Natural Community Conservation Plan Annual Report 2022. https://www.cocohcp.org/ArchiveCenter/ViewFile/Item/71
ECORP Consulting. 2017. Winters Highland Survey Report. May 24, 2017
ECorp Consulting. 2018-2022. 2018-2022 Annual Reports. Bryte Ranch Conservation Bank, Sacramento, California.
ECorp Consulting. 2023. 2023 Annual Report. Bryte Ranch Conservation Bank, Sacramento, California.
Edwards Air Force Base (EAFB). 2001. Integrated Natural Resources Management Plan for Edwards Air Force Base, California. Environmental Management Office.
Emerson, W.O. 1884. Californian Notes. Ornithologist and Oologist. Vol. IX, No. 12, December 1884, pp. 143-144.
Emlen, J.M. and E.K. Pilkitch. 1989. Animal Population Dynamics: Identification of Critical Components. Ecol. Model. 44: 253-273.
England, A.S., M.K. Sogge, and C. Van Riper III. 1988. Avian Species of Management Concern:
Mill and Deer Creek Drainages, Tehama County, California. Cooperative National Park Resources Study Unit. Technical Report No. 33. Final Report to National Park Service, October 1988.
Errington, P.L. and L.J. Bennett. 1935. Food Habits of Burrowing Owls in Northwestern Iowa.
Wilson Bulletin 47: 125-128.
Estep, J.A. 1989. Avian Mortality At Large Wind Energy Facilities in California: Identification of A Problem. California Energy Commission staff report.
Evans, D.L. 1982. Status Report on Twelve Raptors. U.S. Department of the Interior, Fish and Wildlife Service. Scientific Report No. 238. pp. 13-17.
Evermann, B.W. 1886. A List of the Birds Observed in Ventura County, California. Auk. Vol. III, No. 1, January 1886, p. 93.
Faanes, C.A. and G.R. Lingle. 1995. Breeding Birds of the Platte River Valley of Nebraska.
Northern Prairie Wildlife Research Center, Jamestown, ND.
Feeney, L.R. 1997. Burrowing Owl Site Tenacity Associated with Relocation Efforts. Pages 132- 137 in Lincer, J. L. and K. Steenhof (editors). 1997. The Burrowing Owl, Its Biology and Management; Including the Proceedings of the First International Burrowing Owl Symposium.
Raptor Research Report Number 9.
Field Museum of Natural History (FMNH). 2001. Collection data provided by David Willard, Collections Manager – Birds. Field Museum of Natural History, Chicago, Illinois.
184
Fisher, A.K. 1893. Report on the Ornithology of the Death Valley Expedition of 1891, Comprising Notes of the Birds Observed in Southern California, Southern Nevada, and Parts of Utah. North American Fauna No. 7: 7-158.
Fisher, W.K. 1900. A list of Birds Observed on Mt. St. Helena, California. Condor. Volume 2, Number 6, November-December 1900, p. 136.
Fisher, W.K.1904. List of Birds of Santa Clara County and Santa Cruz Mountains, Exclusive of Water Birds. Handbook of Birds of the Western United States, pp. 1i-1iv. (F.M. Bailey, editor).
Houghton, Mifflin and Company.
Fowler, F.H. 1931. Studies of Food and Growth of the Prairie Falcon. Condor. Volume XXXIII, Number 5, September-October 1931, pp. 193-201.
Fund for Animals (FFA). 2002. Comments on Draft Environmental Assessment for Renewal of a Migratory Bird Treaty Act Permit to Take Migratory Birds on Anacapa Island, California.
Garcelon, D.K. and G.W. Roemer. 1990. The Reintroduction of Bald Eagles on Santa Catalina Island, California. In Bryant, P.B. and J. Remington (editors). Endangered Wildlife and Habitats in Southern California. Memoirs of the Natural History Foundation of Orange County. A collection of occasional papers published by the Natural History Foundation of Orange County.
Volume 3.
Garrett, K. and J. Dunn. 1981. Birds of Southern California. Status and Distribution. Los Angeles Audubon Society.
Gervais, J.A. 2002. Evaluating Space Use and Pesticide Exposure Risk for Burrowing Owls in an Agricultural Environment. Ph.D. Dissertation, Oregon State University, Corvallis, Oregon.
Gervais, J.A. and R.G. Anthony. 2003. Interactions of Chronic Organochlorine Contaminants and Environmental Variability in the Demographics of a Population of Burrowing Owls.
Ecological Applications 13(5): 1250-1262.
Gervais, J.A. and D.H. Catlin. 2004. Temporal Patterns of DDE in Burrowing Owl Eggs from the Imperial Valley, California. The Southwestern Naturalist 49(4): 509-512.
Gervais, J.A. and D.K. Rosenberg. 1999. Western Burrowing Owls in California Produce Second Brood of Chicks. Wilson Bulletin 111(4): 569-571.
Gervais, J.A. and D.K. Rosenberg. 2003. Draft Bird Species of Special Concern Species Account. Prepared for California Department of Fish and Game under contract with Point Reyes Bird Observatory.
Gervais, J.A., D.K. Rosenberg, D.M. Fry and L.A. Trulio. 1997. Evaluation of Contaminant Residues in Burrowing Owl Populations from Central and Southern California. Institute for Bird Populations. Point Reyes Station, California. Publication No. 79.
Gervais, J.A., D.K. Rosenberg, D.M. Fry, L.A. Trulio and K.K. Strum. 2000. Burrowing Owls and Agricultural Pesticides: Evaluation of Residues and Risks for Three Populations in California, USA. Environmental Toxicology and Chemistry 19: 337-343.
185
Gervais, J.A., D.K. Rosenberg and R.G. Anthony. 2003. Space Use and Pesticide Exposure Risk of Male Burrowing Owls in an Agricultural Landscape. Journal of Wildlife Management 67(1): 156-165.
Gervais, J.A., C.M. Hunter and R.G. Anthony. 2006. Interactive Effects of Prey and p,p’-DDE on Burrowing Owl Population Dynamics. Ecological Applications 16(2): 666–677.
Gervais, J.A., D.K. Rosenberg and L.A. Comrack. 2008. Species Accounts: Burrowing Owl (Athene cunicularia). Pages 218-226 in Shuford, W.D. and T. Gardali (editors). 2008. California Bird Species of Special Concern: A Ranked Assessment of Species, Subspecies, and Distinct Populations of Birds of Immediate Conservation Concern in California. Studies of Western Birds
1. Western Field Ornithologists, Camarillo, California, and California Department of Fish and Game, Sacramento.
Gilman, M.F. 1934. Notes on Birds in Death Valley. Condor. Volume XXXVII, Number 5, September-October 1934, p. 241.
Gilmer, D.S., M.R. Miller, R.D. Bauer, and J.R. LeDonne. 1982. California’s Central Valley Wintering Waterfowl: Concerns and Challenges. Transactions of the North American Wildlife Natural Resources Conference 47: 441-452.
Gleason, R.L. and T.H. Craig. 1979. Food Habits of Burrowing Owls in Southeastern Idaho.
Great Basin Naturalist 39: 274-276.
Gleason, R.S. and D R. Johnson. 1985. Factors Influencing Nesting Success of Burrowing Owls in Southeastern Idaho. Great Basin Naturalist 45: 81-84.
Glover, F.A. 1953. Summer Foods of the Burrowing Owl. Condor 55: 275.
Glover, S. 2009. Breeding Bird Atlas of Contra Costa County. Mount Diablo Audubon Society, Walnut Creek, CA.
Goldman, E.A. 1908. Summer Birds of the Tulare Lake Region. Condor. Volume X, Number 5, September-October 1908, p. 263.
Gomez, E.A., H.L. Prestridge and J.A. Smith. 2023. Anthropogenic Threats to Owls: Insights from Rehabilitation Admittance Data and Rodenticide Screening in Texas. Plos One 18.8 e0289228. https://doi.org/10.1371/journal.pone.0289228
Gordon, B.L. 1974. Monterey Bay Area: Natural History and Cultural Imprints. Department of Geography, San Francisco State University. Boxwood Press, Pacific Grove, California.
Gordon, B.L. 1996. Monterey Bay Area: Natural History and Cultural Imprints. 3rd edition.
Department of Geography, San Francisco State University. Boxwood Press, Pacific Grove, California.
Gorman, L.R., D.K. Rosenberg, N.A. Ronan, K.L. Haley, J.A. Gervais and V. Franke. 2003.
Estimation of Reproductive Rates of Burrowing Owls. Journal of Wildlife Management 67(3):493–500.
186
Grant, R.A. 1965. The Burrowing Owl in Minnesota. Loon 37: 2-17. https://moumn.org/loon/view_frame.php?page=2&year=1965
Green, G.A. 1983. Ecology of Breeding Burrowing Owls in the Columbia Basin, Oregon. M.S.
Thesis. Oregon State University, Corvallis, Oregon.
Green, G.A. and R.G. Anthony. 1989. Nesting Success and Habitat Relationships of Burrowing Owls in the Columbia Basin, Oregon. Condor 91: 347-354.
Greenbelt Alliance. 2023. HomeGrown: Tools for Local Farms and Ranches. https://www.greenbelt.org/homegrown/
Griggs, F.T. 1992. The Remaining Biological Diversity of the San Joaquin Valley, California. Pp. 11-16 in Williams, D., F.S. Byrne, and T.A. Rado (editors). Endangered and Sensitive Species of the San Joaquin Valley, California: Their Biology, Management, and Conservation. California Energy Commission, Sacramento, California.
Grinnell, H.W. 1936. Minutes of Cooper Club Meeting. Condor. Volume XXXVIII, Number 1, January-February 1936, p. 48.
Grinnell, J. 1898. Land Birds Observed in Mid-Winter on Santa Catalina Island, California. Auk.
Vol. XV, No. 3, July 1898, p. 234.
Grinnell, J. 1914. An Account of the Mammals and Birds of the Lower Colorado River Valley.
University of California Publications in Zoology; v. 12, no. 4, p. 51-294.
Grinnell, J. 1915. A Distributional List of the Birds of California. Pacific Coast Avifauna Number
11. Cooper Ornithological Club.
Grinnell, J. 1923. Observations Upon the Bird Life of Death Valley. Proceedings of the California Academy of Sciences; v. 13, no. 5.
Grinnell, J. and A.H. Miller. 1944. The Distribution of the Birds of California. Pacific Coast Avifauna, no.27. Cooper Ornithological Club, Berkeley, California.
Grinnell, J. and H.S. Swarth. 1913. An Account of the Birds and Mammals of the San Jacinto Area of Southern California with Remarks Upon the Behavior of Geographic Races on the Margins of their Habitats. University of California Publications in Zoology; v. 10, no. 10.
University of California Press, Berkeley, California.
Grinnell, J. and M.W. Wythe. 1927.Directory to the Bird-Life of the San Francisco Bay Region.
Pacific Coast Avifauna Number 18. Cooper Ornithological Club.
Gross, L. 2019. Water Savings May Hurt Burrowing Owls. High Country News. January 21, 2019.
Haley, K.A. 2002. The Role of Food Limitation and Predation on Reproductive Success of Burrowing Owls in Southern California. M.S. Thesis, Oregon State University, Corvallis, Oregon.
Hall, D.B and C.J. Conway. 2021. Western Burrowing Owl Satellite-Tracking Study. DOE Mission Support and Test Services, USGS, and University of Idaho. DOE/NV/03624—0931 187
Hallmann, C.A., Foppen, R.P.B., van Turnhout, C.A.M., de Kroon, H., and Jongejans, E. 2004.
Declines in Insectivorous Birds are Associated with High Neonicotinoid Concentrations. Nature, 511(7509), 341–343. https://doi.org/10.1038/nature13531
Hamilton, W.J. 1941. A Note on the Food of the Western Burrowing Owl. Condor 3: 74.
Hansen, H.E. and W.A. Squires. 1917. A List of the Birds Breeding in San Francisco County, California. Condor. Volume XIX, Number 2, March-April 1917, p. 60.
Harman, L.M. and J.H. Barclay. 2007. A Summary of California Burrowing Owl Banding Records. Pages 123-131 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Harris, R.D. 1987. Burrowing Owl Relocation, Harbor Bay, Alameda, California. Larry Seeman Associates, Inc., Berkeley, California.
Hartzell, L.B. 1888. Nesting of the Burrowing Owl. Ornithologist and Oologist. Vol. XIII, No. 6, June 1888, pp. 85-86.
Haug, E.A. 1985. Observations on the Breeding Ecology of Burrowing Owls in Saskatchewan.
M.S. Thesis, University of Saskatchewan, Saskatoon.
Haug, E.A., B.A. Millsap, and M.S. Martell. 1993. The Burrowing Owl (Speotyto cunicularia). In Poole, A. and F. Gill (editors). The Birds of North America, No. 61. Philadelphia: The Academy of Natural Sciences; Washington, D.C. The American Ornithologists’ Union.
Haug, E.A. and L.W. Oliphant. 1987. Breeding Biology of Burrowing Owls in Saskatchewan. Pp. 269-271 in Holroyd, G.L., W.B. McGillivray, P.H.R. Stepney, D.M. Ealey, G.C. Trottier, and K.E.
Eberhart (editors). Endangered Species in the Prairie Provinces. Provincial Museum of Alberta Occasional Paper, No. 9.
Haug, E.A. and L.W. Oliphant. 1990. Movements, Activity Patterns, and Habitat Use of Burrowing Owls in Saskatchewan. Journal of Wildlife Management 54: 27-35.
Henderson Ecology & Planning (HEP). 2004. Western Burrowing Owl Species Account and Conservation Strategy. Prepared for Sacramento County. Third Draft South Sacramento HCP.
Henderson, L.A. and L.A. Trulio. 2019. Can California Ground Squirrels Reduce Predation Risk to Burrowing Owls? Journal of Raptor Research 53(2):172–179.
Hennessy, S.M., C. Wisinski, J.P. Montagne, K. Marshall, D.M. Shier, R.R. Swaisgood, and L.A.
Nordstrom. 2015. Project Report 2015: An Adaptive Management Approach to Recovering Burrowing Owl Populations and Restoring a Grassland Ecosystem in San Diego County. San Diego Zoo Institute for Conservation Research, Escondido, CA.
Hennessy, S.M., S.A. Marczak, L.A. Nordstrom and R.R. Swaisgood. 2018. Reconsidering Habitat Associations in the Anthropocene. Global Ecology and Conservation 14:e00397.
188
Hennessy, S., C. Wisinski, N. Ronan, C. Gregory, R. Swaisgood, and L. Nordstrom. 2020.
Assessing California's Relocation Guidelines for Burrowing Owls Impacted by Renewable Energy Development. California Energy Commission. Publication Number: CEC-500-2020-051. https://ww2.energy.ca.gov/2020publications/CEC-500-2020-051/CEC-500-2020-051.pdf
Hennessy, S.M., C.L. Wisinski, N.A. Ronan, C.J. Gregory, R.R. Swaisgood and L.A. Nordstrom. 2022. Release Strategies and Ecological Factors Influence Mitigation Translocation Outcomes for Burrowing Owls: A Comparative Evaluation. Animal Conservation 25: 614–626.
Henny, C.J., L.J. Blus, and T.E. Kaiser. 1984. Heptachlor Seed Treatment Contaminates Hawks, Owls, and Eagles of Columbia Basin, Oregon. Raptor Research 18: 41-48.
Heritage Environmental Consultants (HEC). 2013. Burrowing Owl Relocation, Mitigation and Monitoring Plan Corcoran Solar Generation Project. Prepared for California Department of Fish and Wildlife.
Hjertaas, D.G. 1997. Recovery Plan for the Burrowing Owl in Canada. Pages 107-111 in J.L.
Lincer and K. Steenhoff (editors). The Burrowing Owl: Its Biology and Management. Raptor Research Report Number 9.
Higgins, P. 2015. Issues with Burrowing Owl Mitigation Procedures & the Status of Burrowing Owls in Santa Clara County 2015. California Burrowing Owl Consortium Conference, October 2015.
Hobbs, R.J., E. Higgs and J.A. Harris. 2009. Novel Ecosystems: Implications for Conservation and Restoration. Trends in Ecology and Evolution 24:599–605.
Hoetker, G.M. and K.W. Gobalet. 1999. Predation on Mexican Free-Tailed Bats by Burrowing Owls in California. Journal of Raptor Research 33(4): 333-335.
Holmes, C. and K. Novick. 1993. Draft Honey Lake Wildlife Area Management Plan. State of California, Department of Fish and Game. Sacramento, California.
Holmgren, M.A. and P.W. Collins. 1999. Final Report on the Distribution and Habitat Associations of Six Bird Species of Special Concern at Vandenberg Air Force Base, Santa Barbara County, California. Prepared for Vandenberg Air Force Base. Museum of Systematics and Ecology, U.C. Santa Barbara, and Santa Barbara Museum of Natural History.
Holroyd, G.L., C.J. Conway and H.E. Trefry. 2011. Breeding Dispersal of a Burrowing Owl from Arizona to Saskatchewan. The Wilson Journal of Ornithology, 123(2), pp.378-381.
Hooper, M.J., et al. 1989. Organophosphorus Insecticide Exposure in Hawks Inhabiting Orchards During Winter Dormant-Spraying. Bulletin of Environmental Contamination and Toxicology 42: 651-659.
Hooper, M.J., P. Mineau, M.E. Zaccagnini, G.W. Winegrad, and B. Woodbridge. 1999.
Monocrotophos and the Swainson’s Hawk: A Unique International Partnership Is Helping to Combat Pesticide Threats to Migratory Birds. Pesticide Outlook 10 (3): 97-102.
189
Hothem, R.L., D.L. Roster, K.A. King, T.J. Keldson, K.C. Marois, and S.E. Wainwright. 1995.
Spatial and Temporal Trends of Contaminants in Eggs of Wading Birds from San Francisco Bay, CA. Environmental Toxicology and Chemistry 14: 1319-1331.
Howell, A.B. 1917. Birds of the Islands Off the Coast of Southern California. Pacific Coast Avifauna Number 12. Cooper Ornithological Club, Hollywood, California, 1912. pp. 59-60.
Howell, A.B. and A. Van Rossem. 1915. Additional Observations on the Birds of the Lower Colorado Valley in California. Condor. Volume XVII, Number 6, November-December 1915, p. 233.
Howell, J.A. 1997. Bird Mortality at Rotor Swept Area Equivalents, Altamont Pass and Montezuma Hills, California. Transactions of the Western Section of the Wildlife Society 33: 24-
29. Howell, T.R. 1964. Notes on Incubation and Nestling Temperatures and Behavior of Captive Owls. Wilson Bulletin Vol. 76, No. 1, March 1964, pp. 28-36.
H.T. Harvey and Associates. 1993. Manteca Burrowing Owl Relocation. Project No. 712-05.
Alviso, California.
H.T. Harvey and Associates. 1994. Environmental Impact Report on the Burrowing Owl:
Interland-Mission College Development. Prepared for Mindigo and Associates.
H. T. Harvey and Associates. 2013-2018. CVSR Conservation Lands Habitat Mitigation and Monitoring Plan Annual Reports. Prepared for SunPower Corporation.
H.T. Harvey and Associates. 2015-2016. Sparling Ranch Conservation Bank Biological Resources Survey. BEI Exhibit H.
Humann-Guilleminot, S., Laurent, S., Bize, P., Roulin, A., Glauser, G., and Helfenstein, F. 2021.
Contamination by Neonicotinoid Insecticides in Barn Owls (Tyto alba) and Alpine Swifts (Tachymarptis melba). Sci. Total Environ. 785:147403.
https://doi.org/10.1016/j.scitotenv.2021.147403.
Hunt, G.L., Jr. and M.W. Hunt. 1974. Trophic Levels and Turnover Rates: The Avifauna of Santa Barbara Island, California. Condor. Volume 76, Number 4, Winter 1974, pp. 363-368.
ICF International. 2012. Final Santa Clara Valley Habitat Plan. Prepared for: City of Gilroy, City of Morgan Hill, City of San José, County of Santa Clara, Santa Clara Valley Transportation Authority, Santa Clara Valley Water District.
ICF International. 2018. Yolo Habitat Conservation Plan/Natural Community Conservation Plan.
Volume 1. Final. Prepared by ICF for Yolo Habitat Conservancy. Woodland, CA. https://ecos.fws.gov/docs/plan_documents/thcp/thcp_2894.pdf
ICF International. 2023. Biological Effectiveness Monitoring for the Natomas Basin Habitat Conservation Plan Area 2022 Annual Survey Results. April. Agency Version—Final. (ICF 104332.) Sacramento, CA. Prepared for the Natomas Basin Conservancy, Sacramento, CA.
190
Imperial Irrigation District (IID). 2006. Planning Agreement by and among Imperial Irrigation District, the California Department of Fish and Game, and the United States Fish and Wildlife Service Regarding the Imperial Valley Natural Community Conservation Plan and Habitat Conservation Plan. Planning Agreement No. 2810 - 2004 - 01 - 06. February 2006.
Imperial Irrigation District (IID). 2010. 2010 Annual Report of Imperial Irrigation District Pursuant to SWRCB Revised Order WRO 2002-013.
Imperial Irrigation District (IID). 2012. 2012 Burrowing Owl Monitoring Results, Imperial Irrigation District Rights-Of-Way, Imperial County, California. Prepared by AECOM for Imperial Irrigation District.
Imperial Irrigation District (IID). 2023. HCP/NCCP Process. https://www.iid.com/water/library/qsa-water-transfer/environmental-assessments-permits/hcp- nccp-process
Insignia Environmental. 2009. 2008/2009 Annual Report for the Buena Vista Avian and Bat Monitoring Project (and update of 3rd August 2009). County of Contra Costa: Martinez, CA.
James, P.C. and R.H.M. Espie. 1997. Current Status of the Burrowing Owl in North America: An Agency Survey. Pp. 3-5 in J. L. Lincer and K. Steenhoff (editors). The Burrowing Owl: Its Biology and Management. Raptor Research Foundation, Inc., Boise, Idaho.
James, P.C. and T.J. Ethier. 1989. Trends in the Winter Distribution and Abundance of Burrowing Owls in North America. American Birds 43: 1224-1225.
James, P.C., T.J. Ethier, and M.K. Toutloff. 1997. Parameters of a Declining Burrowing Owl Population in Saskatchewan. Pages 34-37 in J. L. Lincer and K. Steenhoff (editors). The Burrowing Owl, Its Biology and Management: Including the Proceedings of the First International Symposium. Raptor Research Report Number 9.
James P.C. and G.A. Fox. 1987. Effects of Some Insecticides on Productivity of Burrowing Owls. Blue Jay 45: 65-71.
James P.C., G.A. Fox, and T.J. Ethier. 1990. Is the Operational Use of Strychnine to Control Ground Squirrels Detrimental to Burrowing Owls? Journal of Raptor Research 24(4): 120-123.
Jarman, W.M., S.A. Burns, C.E. Bacon, J. Rechtin, S. DeBenedetti, J.L. Linthcum, and B.J.
Walton. 1996. High Levels of HCB and DDE Associated with Reproductive Failure in Prairie Falcons (Falco mexicanus) in California. Bulletin of Environmental Contamination and Toxicology 57: 8-15.
Jasny, M. 1997. Leap of Faith: Southern California’s Experiment in Natural Community Conservation Planning. Natural Resources Defense Council.
Johnsgard, P.A. 1988. North American Owls: Biology and Natural History. Smithsonian Institution Press, Washington, D. C.
Johnson, B.S. 1992. Effects of Demography, Mating Patterns, and Sociality on the population Genetics and Dynamics of Burrowing Owl Athene cunicularia. Dissertation, University of California, Davis.
191
Johnson, B.S. 1997a. Demography and Population Dynamics of the Burrowing Owl. Pages 28- 33 in Lincer, J. L. and K. Steenhof (editors). 1997. The Burrowing Owl, Its Biology and Management: Including the Proceedings of the First International Symposium. Raptor Research Report Number 9.
Johnson, B.S. 1997b. Characterization of Population and Family Genetics of the Burrowing Owl by DNA Fingerprinting with pV47-2. Pages 58-63 in Lincer, J. L. and K. Steenhof (editors). 1997. The Burrowing Owl, Its Biology and Management: Including the Proceedings of the First International Symposium. Raptor Research Report Number 9.
Johnson, B.S. 1997c. Reproductive Success, Relatedness, and Mating Patterns of Colonial Burrowing Owls. Pages 64-67 in Lincer, J.L. and K. Steenhof (editors). 1997. The Burrowing Owl, its Biology and Management. Raptor Research Report Number 9.
Johnson, B.S. and T.A. Schulz. 1985. Biology and Status of the Burrowing Owl on the Campus of the University of California, Davis. Raptor Res. Found. Symp. Biol. Status, and Management of Owls, Sacramento [Abstract].
Johnson, J.W. 1990. The Flora and Fauna of Upper Newport Bay, 1940-55. In Bryant, P.B. and J. Remington (editors), Endangered Wildlife and Habitats in Southern California. Memoirs of the Natural History Foundation of Orange County. A collection of occasional papers published by the Natural History Foundation of Orange County. Volume 3.
Johnson, R.G., J.A. Juskevice, S. Obrebski, J.A. Blake, and E.H. Smith. 1971. Biological Characteristics of Tomales Bay. Environmental Study of Tomales Bay, Volume 4. Pacific Marine Station, Research Report Number 11.
Jones, H.L. and P.W. Collins. 2003. Birds of California’s Channel Islands: Their Distribution and Status. Santa Barbara Museum of Natural History, Santa Barbara, California.
Jones, H.L. and J.M. Diamond. 1976. Short-Time-Base Studies of Turnover in Breeding Bird Populations on the California Channel Islands. Condor. Volume 78, Number 4, Winter 1976, pp. 526-548.
Jones & Stokes. 2000. Draft Carnegie State Vehicle Recreation Area General Plan Amendment Environmental Impact Report. Prepared for California Department of Parks and Recreation, Off- Highway Motor Vehicle Recreation Division.
Jones & Stokes. 2006a. East Contra Costa County HCP and NCCP. Prepared for East Contra Costa County Habitat Conservation Plan Association by Jones & Stokes. https://ecos.fws.gov/docs/plan_documents/thcp/thcp_2908.pdf
Jones & Stokes. 2006b. Final PG&E San Joaquin Valley Operation & Maintenance Habitat Conservation Plan. Prepared for Pacific Gas and Electric Company
Justice-Allen, A. and Loyd, K.A. 2017. Mortality of Western Burrowing Owls (Athene cunicularia hypugaea) Associated with Brodifacoum Exposure. Journal of Wildlife Diseases 53:165-169.
Kareiva, P., S. Andelman, D. Doak, B. Elderd, M. Groom, J. Hoekstra, L. Hood, F. James, J.
Lamoreux, G. LeBuhn, C. McCulloch, J. Regetz, L. Savage, M. Ruckelshaus, D. Skelly, H. 192
Wilbur, K. Zamudio, and NCEAS HCP Working Group. 1999. Using Science in Habitat Conservation Plans. National Center for Ecological Analysis & Synthesis, Santa Barbara, CA, and the American Institute of Biological Sciences, Washington, DC.
KEA Environmental. 1997. Final 1996 Botany and Wildlife Pre-Construction Survey Report for the Alturas Intertie Project. Prepared for Sierra Pacific Power Company, Reno, NV. KEA Environmental, Inc, Sacramento CA
KEA Environmental. 1998. Draft 1998 Special Status Wildlife Pre-Construction Survey Report for the Alturas Intertie Project. Prepared for Sierra Pacific Power Company, Reno, NV. KEA Environmental, Inc, Sacramento CA
Keeler, C.A. 1891. Geographical Distribution of Land Birds in California. IV. The Island Fauna.
Zoe. Volume I, January 1891, pp. 337-343.
Keeler, C.A. 1907. Bird Notes Afield; Essays on the Birds of the Pacific Coast with a Field Check List. P. Elder and Company, San Francisco and New York.
Kemper, J. 1996. Discovering Yolo County Wildlife. Yolo Audubon Society and Yolo Basin Foundation, 1996.
Kennard, J.H. 1975. Longevity Records of North American Birds. Bird-Banding 46: 55-73.
Kern Water Bank Authority (KWBA). 1997. Kern Water Bank Habitat Conservation Plan/Natural Community Conservation Plan.
Kidd, J.W. 2023a. Augmented Eviction Resulting in Pair Fidelity and Successful Nesting in Riverside County, California. Kidd Biological Inc. 2023 Burrowing Owl Symposium, February 6- 7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws- west.org/2023buowsymposium/abstracts?authuser=0
Kidd, J.W. 2023b. 30 Year Review of Experimental Burrowing Owl Relocations Throughout California. Kidd Biological Inc. 2023 Burrowing Owl Symposium, February 6-7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws- west.org/2023buowsymposium/abstracts?authuser=0
Kidd, J.W., P.H. Bloom, C.W. Barrows and C.T. Collins. 2007. Status of Burrowing Owls in Southwestern California. Pages 76-89 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Kirsher, W. 1951. Check List of the Birds of Sacramento and Vicinity. Sacramento State College Publications, Natural History Series No. 2.
Klute, D.S., Ayers, L., Green, M.T. Howe, W.H., Jones, S.L., Shaffer, J.A., and Zimmerman, T.S. 2003. Status Assessment and Conservation Plan for the Western Burrowing Owl in the United States. USDI, Fish and Wildlife Service Biological Technical Publication ; FWS/BTP- R6001-2003, Washington, DC, USA.
Klute, D.S., Ayers, L., Green, M.T. Howe, W.H., Jones, S.L., Shaffer, J.A., and Zimmerman, T.S. 2007. Status Assessment and Conservation Plan for the Western Burrowing Owl in the 193
United States – California Summary. Pages 109-114 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc.
Bird Populations Monographs No. 1.
Konrad, P M. and D.S. Gilmer. 1984. Observations on the Nesting Ecology of Burrowing Owls in Central North Dakota. Prairie Naturalist 16: 129-130.
Korfanta, M.N. 2001. Population Genetics of Migratory and Resident Burrowing Owls (Athene cunicularia) Elucidated by Microsatellite DNA Markers. M.S. Thesis, University of Wyoming, Laramie, Wyoming.
Korfanta, N.M., D.B. McDonald, T.C. Glenn and C.M. Handel. 2005. Burrowing Owl (Athene cunicularia) Population Genetics: A Comparison of North American Forms and Migratory Habits.
Auk 122:464–478.
Kosciuch, K., D. Riser-Espinoza, M. Gerringer and W. Erickson. 2020. A Summary of Bird Mortality at Photovoltaic Utility Scale Solar Facilities in the Southwestern U.S. PLOS One, 15(4), Article e0232034. https://doi.org/10.1371/journal.pone.0232034
Koshear, J., C. Shafer, E.F. Van Mantgem and R.V. Olsen. 2007. Burrowing Owl Management at Colonel Allensworth State Historic Park. Pages 155-164 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Kuenzi, A.J. and M.L. Morrison. 1998. Avian Habitat Use and Flight Behavior in Relation to Bird- Aircraft Strikes in Western U.S. Agricultural Lands. In Transactions of the Western Section of the Wildlife Society 34:1-8, pp. 1-7.
La Claire, J. 2000. Lake Perris SRA and San Jacinto Wildlife Area Burrowing Owl Survey May- July 2002. Unpublished report. California State Parks, Inland Empire District, Resource Management Program.
Lamb, C.C. 1929. Land Birds of a Pacific Coast Sea Voyage. Condor. Volume XXXI, Number 1, January-February 1929, p. 36.
Landry, R.E. 1979. Growth and Development of the Burrowing Owl, (Athene cunicularia).
Unpublished M.A. Thesis. California State University, Long Beach. 66pp.
Lantz, S.J. and C.J. Conway. 2009. Factors Affecting Daily Nest Survival of Burrowing Owls Within Black-Tailed Prairie Dog Colonies. The Journal of Wildlife Management, 73(2), pp.232- 241.
Lawrence Livermore National Laboratory (LLNL). 1998. Site 300 Ecology.
Lehman, P.E. 1994. The birds of Santa Barbara County, California. Vertebrate Museum, University of California, Santa Barbara, 1994. pp. 175-176.
Lehman, P., G. McCaskie and P. Unitt. 2021. San Diego County Avian Records Database, 2002-2020.
194
Lenihan, C. 2007. The Ecological Role of the California Ground Squirrel (Spermophilus beecheyi). PhD, University of California, Davis, Davis, CA.
Li, Y., Miao, R. and Khanna, M. 2020. Neonicotinoids and Decline in Bird Biodiversity in the United States. Nat Sustain 3, 1027–1035. https://doi.org/10.1038/s41893-020-0582-x
Ligon, J.S. 1961. New Mexico Birds. University of New Mexico Press, Albuquerque, New Mexico.
Lincer, J.l. and P.H. Bloom. 2007. The Status of the Burrowing Owl in San Diego County, California. Pages 90-102 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Linton, C.B. 1908a. Notes from Santa Cruz Island. Condor. Volume X, Number 3, May-June 1908, p. 127.
Linton, C B. 1908b. Notes from Buena Vista Lake, May 20 to June 16, 1907. Condor. Volume X, Number 5, September-October 1908, p. 197.
Linton, C.B. 1908c. Notes from San Clemente Island. Condor. Volume X, Number 2, March- April 1908, p. 84.
Lohoefener, R. and C.A. Ely. 1978. The Nesting Birds of LaCreek National Wildlife Refuge.
South Dakota Bird Notes (June): 24-30.
Los Angeles County Museum (LACM). 2001. Collection data provided by Christina Couroux, Ornithology Curatorial Assistant. Natural History Museum of Los Angeles County.
Louise M. Darling Biomedical Library (LMDBL). 2001. On-line database of History and Special Collections. California Digital Library. www.cdlib.org
Lovich, J.E. and J.R. Ennen. 2011. Wildlife Conservation and Solar Energy Development in the Desert Southwest, United States. BioScience, Volume 61, Issue 12, December 2011, pp. 982– 992.
LSA. 2009-2018. 2007-2017 Annual Reports Elsie Gridley Mitigation Bank, Solano County, California. Prepared for Wetland Resources LLC.
LSA. 2014. Fifth Annual Monitoring Report (2013) for the Prewett Family Park Burrowing Owl Preserve, Antioch, California.
LSA. 2018-2022. Muzzy Ranch Conservation Bank 2017-2022 Monitoring Reports. Muzzy Ranch Conservation Bank Project, County of Solano, California. Submitted Canon Station, LLC.
Lutz, R.S. and D.L. Plumpton. 1999. Philopatry and Nest Site Reuse by Burrowing Owls:
Implications for Productivity. Journal of Raptor Research 33:149–153.
Lynch, J.F. and N.K. Johnson. 1974. Turnover and Equilibria in Insular Avifaunas with Special Reference to the California Channel Islands. Condor. Volume 76, Number 4, Winter 1974, pp. 370-380.
195
Macıas-Duarte, A. and C.J. Conway. 2015. Distributional Changes in the Western Burrowing Owl (Athene cunicularia hypugaea) in North America from 1967 to 2008. Journal of Raptor Research 49(1): 75–83.
Macıas-Duarte, A., C.J. Conway, G.L. Holroyd, H.E. Valdez-Gomez and M. Culver. 2019.
Genetic Variation Among Island and Continental Populations of Burrowing Owl (Athene cunicularia) Subspecies In North America. Journal of Raptor Research 53(2):127–133.
Macıas-Duarte, A., C.J. Conway, A. Munguia-Vega and M. Culver. 2020a. Novel Microsatellite Loci for the Burrowing Owl Athene cunicularia. Conservation Genetics Resources.
Macías-Duarte, A., C.J. Conway and M. Culver. 2020b. Agriculture Creates Subtle Genetic Structure Among Migratory and Nonmigratory Populations of Burrowing Owls Throughout North America. Ecology and Evolution 10:10697–10708.
Madden, J. An Analysis of the Burrowing Owls on the Central Coast Region of California.
Unpublished report. Environmental Studies Department, San Jose State University.
Mailliard, J. 1900. Land Birds of Marin County, Cal. Condor. Volume 2, Number 3, May-June 1900, p. 63.
Mailliard, J. 1930. Handbook of the Birds of Golden Gate Park. California Academy of Sciences, San Francisco. p. 54.
Mailliard, J. and J.W. Mailliard. 1901. Birds Recorded at Paicines, San Benito Co., California.
Condor. Volume 3, Number 5, September-October 1901, p. 122.
Manning, J.A. 2009. Burrowing Owl Population Size in the Imperial Valley, California: Survey and Sampling Methodologies for Estimation. Final report to the Imperial Irrigation District, Imperial, CA.
Marcus H. Bole & Associates. 2014. Bryte Ranch Conservation Bank, Sacramento County, California. 2014 Biological Monitoring Report.
Marczak, S., C.L. Wisinski, S.M. Hennessy, J.P. Montagne, M. Stevens, J. Hargis, D.M. Shier, R.R. Swaisgood and L.A. Nordstrom. 2017. Project Report 2017: An Adaptive Management Approach to Recovering Burrowing Owl Populations and Restoring a Grassland Ecosystem in San Diego County. San Diego Zoo Institute for Conservation Research, Escondido, CA.
Marczak, S., C. L. Wisinski, S. M. Hennessy, M. Stevens, S. Perez, D. Angel, R. R. Swaisgood, and L. A. Nordstrom. 2018. Project Report 2018: Advancing Burrowing Owl Conservation in San Diego County through Mitigation Measures using Science and Adaptive Management. San Diego Zoo Institute for Conservation Research, Escondido, CA.
Marczak, S. 2023.Burrowing Owl Monitoring, Research and Conservation in San Diego County.
Diego Zoo Wildlife Alliance. 2023 Burrowing Owl Symposium, February 6-7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws- west.org/2023buowsymposium/abstracts?authuser=0
196
Marine Corps Air Ground Combat Center (MCAGCC). 1996. Multiple Land Use Management Plan, Twentynine Palms, California 1996-2000.
Marsh, R.E. 1987. Ground Squirrel Control Strategies in Californian Agriculture. Pp. 261-267 in C.G.J. Richards and T.Y. Ku (editors). Control of Mammal Pests. Taylor and Francis, London, New York, and Philadelphia.
Martell, M., H.B. Tordoff, and P.T. Redig. 1994. The Introduction of Three Native Raptors into the Midwestern United States. Raptor Conservation Today, 465-470.
Marti, C.D. 1974. Feeding Ecology of Four Sympatric Owls. Condor 76: 45-61.
Marti, C.D. and J.S. Marks. 1989. Medium-Sized Owls. In Proceedings of the Western Raptor Management Symposium and Workshop. National Wildlife Federation, Washington, D. C.
Martin, D.J. 1973. Selected Aspects of Burrowing Owl Ecology and Behavior. Condor 75: 446- 456.
McCormick Biological, Inc. 2016. Draft Habitat Management Plan, Panoche Valley Solar Project Conservation Lands, San Benito and Fresno Counties. Prepared for Panoche Valley Solar, LLC.
McGregor, R.C. 1898. Note on Speotyto cunicularia obscura Stephens. Auk. Volume XV, No. 2, April 1898, p. 187.
McGregor, R.C. 1901. A List of the Land Birds of Santa Cruz County, California. Pacific Coast Avifauna No. 2. Cooper Ornithological Club of California, p. 8.
McGriff, D. 2007. Burrowing Owl Data in the California Natural Diversity Database. Pages 178- 184 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
McNerney, J.T. 2005-2014. Biannual Monitoring Reports of the Burrowing Owl Reserve at Yolo County Grasslands Park from 2005-2006; 2010-2014.
McNerny, J.T. and M. Sears. 2007. Burrowing Owl Protection at the Local Level: The City of Davis Disking Ordinance. Pages 137-140 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Meads, L. 2023. Review and Lessons Learned Over 40 Years of Captive Bred Reintroduction of the Western Burrowing Owl (Athene cunicularia hypugaea) in the Grasslands of British Columbia, 1983-2022. Burrowing Owl Conservation Society of BC. 2023 Burrowing Owl Symposium, February 6-7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws-west.org/2023buowsymposium/abstracts?authuser=0
Medenhall, V.M. and L.F. Pank. 1980. Secondary Poisoning of Owls by Anticoagulant Rodenticides. Wildlife Society Bulletin 8: 311-315.
Medvitz, A. and A.D. Sokolow. 1995. Population Growth Threatens Agriculture, Open Space.
California Agriculture 49(6): 11-15.
197
Menzel, S. 2014. An Assessment of Artificial Burrows for Burrowing Owls in Northern California.
Master's Thesis, San Jose State University.
Menzel, S. 2015. Burrowing Owls Covered Under Conservation Plans in California – Are These Plans Actually Protecting the Species? California Burrowing Owl Consortium Conference, October 2015.
Menzel. S. 2018. Artificial Burrow Use by Burrowing Owls in Northern California. Journal of Raptor Research 52(2):167–177.
Menzel, S. C. Portman and R.L. Wilkerson. 2024. Precipitous Decline of Western Burrowing Owls in Yolo County, Northern California. Burrowing Owl Preservation Society and Institute for Bird Populations. Manuscript submitted for publication.
Mercado-Borrayo, B.M., Cram, H.S., Rosas Pérez, I., Hernández Quiroz, M., and Ponce De León Hill, C. 2015. Organophosphorus and Organochlorine Pesticides Bioaccumulation by Eichhornia crassipes in Irrigation Canals in an Urban Agricultural System. International Journal of Phytoremediation 17(7):701–708. doi: 10.1080/15226514.2014.964841
Merriam, C.H. 1899. Results of a Biological Survey of Mount Shasta California. North American Fauna No. 16. U.S. Department of Agriculture, Division of Biological Survey. Government Printing Office, Washington.
Merriam, F.A. 1896. Notes on Some of the Birds of Southern California. Auk. Vol. XIII, No. 2, April 1896, p. 117.
Miles, S.R. and C.B. Goudey. 1997. Ecological Subregions of California. USDA Forest Service, Pacific Southwest Region, San Francisco, CA.
Miller, J.K. 2007. Petition to List the Western Burrowing Owl in California. Pages 169-177 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Miller, J.M. 1903. Notes on the Bird Conditions of the Fresno District. Condor. Volume V, Number 4, July-August 1903, pp. 89-90.
Millsap, B.A. 2002. Survival of Florida Burrowing Owls Along an Urban-Development Gradient.
Journal of Raptor Research 36:3-10.
Millsap, B.A. and C. Bear. 1988. Cape Coral Burrowing Owl Population Monitoring. Annual Performance Report, Florida Game, Freshwater Fish Commission. Tallahassee, Florida.
Mineau, P. and H. Kern. 2023. Neonicotinoid Pesticides, Failing to Come to Grips with a Predictable Environmental Disaster. American Bird Conservancy. https://abcbirds.org/wp- content/uploads/2023/07/2023-Jul20-ABC-Neonicotinoid-Insecticides-Report.pdf
Mineau, P., M.R. Fletcher, L.C. Glaser, N.J. Thomas, C. Brassard, L.K. Wilson, J.E. Elliott, L.
Lyon, C.J. Henny, T. Bollinger, and S L. Porter. 1999. Poisoning of Raptors with Organophosphorus and Carbamate Pesticides with Emphasis on Canada, U.S. and U.K.
Journal of Raptor Research 33(1): 1-37.
198
Monson, G. and A.R. Phillips. 1981. Annotated Checklist of the Birds of Arizona. University of Arizona Press, Tucson, Arizona.
Moore Laboratory of Zoology (MLZ). 2001. Collection data provided by James Northern, Collections Manager. Moore Laboratory of Zoology, Occidental College, Los Angeles, California.
Mowbray, M.V. 1947. Notes on the Birds of the Upper Salinas Valley, California. Condor.
Volume 49, Number 4, July-August 1947, pp. 173-174.
Mueller, T. 2001. Natural Communities Conservation Planning (NCCP): Does Delegation of Endangered Species Protection to the States Protect Species? Published by the Environmental Protection Information Center, Garberville, CA.
Murray, G.A. 1976. Geographic Variation in the Clutch Sizes of Seven Owl Species. The Auk 93:602-613.
Murray, K.G., K. Winnett-Murray, Z.A. Eppley, G.L. Hunt, Jr., and D.B. Schwartz. 1983.
Breeding Biology of the Xantus’ Murrelet. Condor. Volume 85, Number 1, February 1983, p. 16.
Museum of Southwestern Biology (MSB). 2001. Collection data provided by Maureen Leonard, Curatorial Assistant, Division of Birds. Museum of Southwestern Biology, University of New Mexico.
Museum of Vertebrate Zoology (MVZ). 2001. Database of U.C. Berkeley Museum of Vertebrate Zoology specimens.
Nadeau, C., C. Conway and N. Rathbun. 2015. Depth of Artificial Burrowing Owl Burrows Affects Thermal Suitability and Occupancy. Journal of Field Ornithology.
National Museum of Natural History (NMNH). 2001. Collection data provided by Craig Ludwig, Scientific Data Manager, Division of Birds and Mammals. National Museum of Natural History, Smithsonian Institution, Washington, DC.
Natomas Basin Conservancy. 2021. Biological Effectiveness Monitoring for the Natomas Basin Habitat Conservation Plan Area. 2020 Annual Survey Results.
Naval Air Weapons Station (NAWS) China Lake. 2002. Draft Environmental Impact Statement for Proposed Military Operational Increases and Implementation of Associated Comprehensive Land Use and Integrated Natural Resources Management Plans. Prepared with the cooperation of the Bureau of Land Management, Ridgecrest, California.
Naz S., Iqbal, S.S., Manan, A., Chatha, M., and Zia, M. 2023. The Web of Life: Role of Pesticides in the Biodiversity Decline. International Journal of Forest Sciences.
Neff, J.A. 1941. A Note on the Food of Burrowing Owls. Condor. Volume 43, Number 4, July- August 1941, pp. 197-198.
Newton, I., I. Wyllie, A. Gray, and C.V. Eadsforth. 1994. The Toxicity of the Rodenticide Flocoumafen and its Elimination Via Pellets. Pesticide Science 41: 187-193.
199
Noss, R.F. and A.Y. Cooperrider. 1994. Saving Nature’s Legacy: Protecting and Restoring Biodiversity. Island Press, Washington, D. C.
Noss, R.F., M.A. O'Connell, and D.D. Murphy. 1997. The Science of Conservation Planning:
Habitat Conservation Under the Endangered Species Act. Island Press.
Oakland Museum (OM). 2001. Collection data provided by Tom Steller, Interim Curator of Collections. Oakland Museum, Oakland, California.
Ocken, M.A. 2017. Seasonal Habitat Requirements and Use by the Western Burrowing Owl (Athene cunicularia hypugaea) in the Northern Sacramento Valley, California. Master's Thesis, California State University, Chico.
O'Connor, R.J., E. Dunn, D.H. Johnson, S.L. Jones, D. Petiti, K. Pollock, C.R. Smith, J.L. Trapp, and E. Welling. 2000. A Programmatic Review of the North American Breeding Bird Surveys.
Report of a Peer Review Panel.
Office of Environmental Health and Hazard Assessment (OEHHA). 2023. CalEnviroScreen 4.0 Indicator Maps, Pesticide Use Percentile.
https://experience.arcgis.com/experience/ed5953d89038431dbf4f22ab9abfe40d/page/Indicators /?views=Pesticide-Use
Office of Migratory Bird Management (OMBM). 1995. Migratory Nongame Birds of Management Concern in the United States: The 1995 List. U.S. Fish and Wildlife Service, Washington, D. C.
Ohlendorf, H.M. and W.J. Fleming. 1988. Birds and Environmental Contaminants in San Francisco and Chesapeake Bays. Marine Pollution Bulletin 19: 487-495.
Ohlendorf, H.M., D.J. Hoffman, M. Saiki, and T.W. Aldrich. 1986. Embryonic Mortality and Abnormalities of Aquatic Birds: Apparent Impacts of Selenium from Irrigation Drainwater. Sci.
Total Environ. 52: 49-63.
Ohlendorf, H.M., R.L. Hothem, T.W. Aldrich, and A.J. Krynitsky. 1987. Selenium Contamination of the Grasslands, a Major California Waterfowl Area. Sci. Total Environ. 66: 169-183.
Ohlendorf, H.M., A.W. Kilness, J.L. Simmons, R.K. Stroud, D.J. Hoffman, and J.F. Moore. 1988.
Selenium Toxicosis in Wild Aquatic Birds. Journal of Toxicology and Environmental Health 24:
67-92.
Ohlendorf, H.M. and K.C. Marois. 1990. Organochlorines and Selenium in California Night- Heron and Egret Eggs. Environmental Monitoring and Assessment 15: 91-104.
Olberding Environmental. 2023a. Year 1 (2023) Monitoring Report for the Cayetano Creek Mitigation Bank, Contra Costa and Alameda Counties, California.
Olberding Environmental. 2023b. Eagle Ridge Preserve East Suitable Burrowing Owl Foraging Habitat. Letter to CDFW.
Paige, C. 1998. Species Management Abstract: Western Burrowing Owl (Athene cunicularia hypugaea). The Nature Conservancy, Wings of Americas Program, Arlington, Virginia.
200
Palacios, E., D.W. Anderson, E. Meltink, and S. Gonzalez-Guzman. 2000. Distribution and Abundance of Burrowing Owls on the Peninsula and Islands of Baja California. Western Birds 31:89-99.
Pandolfino, E.R., L.A. Douglas, T.D. Manolis and C. Conard. 2021. Sacramento County Breeding Birds, A Tale of Two Atlases and Three Decades of Change. Central Valley Bird Club Special Publication No. 2.
Parsons Harland Bartholmew & Associates, Inc. (PHBA). 2002. Mace Ranch Community Park Draft Environmental Impact Report. Prepared for City of Davis.
Peabody Museum of Natural History (PMNH). 2001. On-line database of Yale University Peabody Museum of Natural History specimens. www.peabody.yale.edu
Peakall, D.B. 1970. Pesticides and the Reproduction of Birds. Scientific American 213: 255-261.
Pemberton, J.R. 1928. Additions to the Known Avifauna of the Santa Barbara Islands. Condor.
Volume XXX, Number 2, March-April 1928, pp. 144-147.
Pemberton, J.R. and H.W. Carriger. 1915. A Partial List of the Summer Resident Land Birds of Monterey County, California. Condor. Volume XVII, Number 5, September-October 1915, p. 194.
Pest Management Regulatory Agency (PMRA). 1995. Carbofuran. Decision Document E95-05.
Pest Management Regulatory Agency, Health Canada, Ottawa, Ontario.
Peterson, N.R. 2023. Population Trends of Breeding Western Burrowing Owls at Two Conserved Sites in Western Riverside County, 2015–2022. California Department of Fish and Wildlife. 2023 Burrowing Owl Symposium, February 6-7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws-west.org/2023buowsymposium/abstracts?authuser=0
Pettingill, O.S. 1981. A Guide to Bird Finding West of the Mississippi. Second edition. Oxford University Press, New York.
Pimm, S.L. 1991. The Balance of Nature?: Ecological Issues in the Conservation of Species and Communities. University of Chicago Press, Chicago, Illinois.
Placer County Conservation Program. 2020. Western Placer County Habitat Conservation Plan/Natural Community Conservation Plan.
https://ecos.fws.gov/docs/plan_documents/thcp/thcp_3186.pdf
Plaza P.I., Martínez-López, E., and Lambertucci, S.A. 2019. The Perfect Threat: Pesticides and Vultures. Science of the Total Environment 687:1207–1218. doi:
10.1016/j.scitotenv.2019.06.160.
Plumpton, D.L. 1992. Aspects of Nest Site Selection and Habitat Use by Burrowing Owls at the Rocky Mountain Arsenal, Colorado. M.S. Thesis, Texas Tech. Univ., Lubbock, Texas.
Plumpton, D.L., and R.S. Lutz. 1993. Influence of Vehicular Traffic on Time Budgets of Nesting Burrowing Owls. Journal of Wildlife Management 57: 612-616. https://www.jstor.org/stable/3809291
201
Point Blue Conservation Science. 2010. Burrowing Owls on the Farallones??! https://www.pointblue.org/farallones_blog/burrowing-owls-on-the-farallones/
Port of Oakland. 1997. Airport Development Program, Oakland International Airport FEIR.
Port of Oakland. 2023. Oakland International Airport Terminal Modernization and Development Project. Draft Environmental Impact Report.
Portman, C. and P. Nieberg. 2012. Burrowing Owl Mitigation Has Failed. Article in the Davis Enterprise, November 11, 2012.
Poulin, R.G., L.D. Todd, E.A. Haug, B.A. Millsap and M.S. Martell. 2020. Burrowing Owl (Athene cunicularia). Birds of the World.
https://birdsoftheworld.org/bow/species/burowl/cur/introduction
Power, M.E., D. Tilman, J.A. Estes, B.A. Menge, W.J. Bond, L.S. Mills, G. Daily, J.C. Castilla, J.
Lubchenco, and R.T. Paine. 1996. Challenges in the Quest for Keystones. Bioscience 46:609- 620
Price, W.W. 1898. Birds of the Campus. The Sequoia 7(26): 310-311.
Priest, J.E. 1997. Age Identification of Nestling Burrowing Owls. The Burrowing Owl: Its Biology and Management. Journal of Raptor Research Report 9:125-127.
Purdue University Cooperative Extension Service (PUCES). 2008. Pesticides and Wildlife: An Introduction to Testing, Registration, and Risk Management. https://ag.purdue.edu/department/extension/ppp/ppp-publications/ppp-30.pdf
Quad Knopf. 2014. Maricopa Sun Solar Complex Project Final Habitat Conservation Plan.
Prepared for Maricopa Sun, LLC.
Rado, T. 2002. BNSF Lateral Pipeline Project Post-Project Biological Monitoring Report, San Bernardino County, California. Prepared for Kinder Morgan Energy Partners, Orange, California, October 2002.
Rahn, M.E., H. Doremus and J. Diffendorfer. 2006. Species Coverage in Multispecies Habitat Conservation Plans: Where’s the Science? BioScience 56(7): 613–619.
Rappole, J.H., S.R. Derrickson, and Z. Hubalek. 2000. Migratory Birds and Spread of West Nile Virus in the Western Hemisphere. Emerging Infectious Diseases 6(4): 319-328.
Ratcliff, B.D. 1986. The Manitoba Burrowing Owl Survey, 1982-1984. Blue Jay 44: 31-37.
Ray, M.S. 1906. A-Birding in an Auto. Auk. Vol. XXIII, No. 4, October 1906, pp. 400-414.
Ray, M.S. 1916. More Summer Birds for San Francisco County. Condor. Volume XVIII, Number 6, November-December 1916. p. 224.
Remsen, J.V., Jr. 1978. Bird Species of Special Concern in California. Prepared for the California Department of Fish and Game. p. 19.
202
Resource Environmental Solutions (RES). 2021-2023. 2020-2023 Elsie Gridley Mitigation Bank Solano County, California. Prepared for Wetland Resources LLC.
Resource Environmental Solutions (RES). 2022. 2022 Annual Report (Year 20), Dolan Ranch Conservation Bank.
Rich, T. 1986. Habitat and Nest-Site Selection by Burrowing Owls in the Sagebrush Steppe of Idaho. Journal of Wildlife Management 50:548-555.
Richmond, J. 1985. Birding Northern California. Mt. Diablo Audubon Society. 142 pp.
Riesz, K. and M. Rodriguez. 2014. CA Department of Fish and Wildlife Perspective on Burrowing Owl. California Department of Fish and Wildlife.
Rigal, S., et al. 2023. Farmland Practices are Driving Bird Population Decline Across Europe.
Proceedings of the National Academy of Sciences 120.21: e2216573120.
Riverside County Transportation and Land Management Agency. 2023. Western Riverside County Multiple Species Habitat Conservation Plan (MSHCP). https://rctlma.org/western- riverside-county-multiple-species-habitat-conservation-plan-mshcp-1
Roberson, D. 1985. Monterey Birds. Monterey Peninsula Audubon Society. pp. 11-12, 144.
Roberson, D. 1993. Atlas of the breeding birds of Monterey County. Monterey Peninsula Audubon Society. pp. 164-165.
Roberts, T.A. and C.O. Gaber. 2007. Habitat Loss and Population Status Estimate for Burrowing Owls in the San Joaquin Valley. Pages 70-75 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Robertson, J.M. 1929. Some Observations on the Feeding Habitats of the Burrowing Owl.
Condor. Volume XXXI, Number 1, January-February 1929, pp. 38-39.
Robertson, J.M. 1930. Roads and Birds. Condor. Volume XXXII, Number 3, May-June 1930, p. 144.
Robertson, J.M. 1931. Some Changes in the Bird Life of Western Orange County, California.
Condor. Volume XXXIII, Number 5, September-October 1931, pp. 204-205.
Rohm and Haas Company. 1991. Material Safety Data Sheet for Kelthane Technical B Miticide.
Philadelphia, PA, pp. 6-46.
Ronan, N.A. 2002. Habitat Selection, Reproductive Success, and Site Fidelity of Burrowing Owls in a Grassland Ecosystem. M.S. Thesis, Oregon State University, Corvallis, OR.
Ronan, N.A. and D.K. Rosenberg. 1999. Burrowing Owl Demography Study: Carrizo Plain 1999 Progress Report.
203
Ronan, N.A. and D.K. Rosenberg. 2014. Response of Burrowing Owls to Experimental Removal of Satellite Burrows. The Journal of Wildlife Management 78:1115–1119.
Rosenberg, D.K. 1999. Burrowing Owl Demography Study: Carrizo Plain 1999 Progress Report.
Institute for Bird Populations. Point Reyes Station, California.
Rosenberg, D.K., and D.F. DeSante. 1997. Demographic Characteristics of Burrowing Owl Populations in California. Progress Report, September 1997. Institute for Bird Populations.
Point Reyes Station, California.
Rosenberg, D.K. and K.L. Haley. 2004. The Ecology of Burrowing Owls in the Agroecosystem of the Imperial Valley, California. Studies in Avian Biology 27, pages 120-135.
Rosenberg, D. and J. Gervais. 2009. An Updated Management Plan for the Burrowing Owl Population at Naval Air Station Lemoore, Lemoore, California. Cooperative Agreement No.
N62473-07-2-0033. Prepared by Oregon Wildlife Institute and The Institute for Bird Populations.
Rosenberg, D.K., J.A. Gervais, H. Ober, and D.F. DeSante. 1998a. An Adaptive Management Plan for the Burrowing Owl Population at NAS Lemoore. Institute for Bird Populations. Point Reyes Station, California. Publication No. 95.
Rosenberg, D.K., L.A. Trulio and D.F. DeSante. 1998b. The Burrowing Owl Demography and Space-Use Research Project in California: Annual Report 1998. Institute for Bird Populations, Publication No. 96.
Rosenberg, D.K., L. Trulio, and D. DeSante 2000. Studies on Space-Use and Demography of Burrowing Owls in California. Annual Field Progress Report.
Rosenberg, D.K., D. Catlin, and K. Tice. 2003. Dispersal of Burrowing Owls in California. The Institute for Bird populations, Unpublished Report.
Rosenberg, K.V., R.D. Ohmart, W.C. Hunter, and B.W. Anderson. 1991. Birds of the Lower Colorado River Valley. University of Arizona Press, Tucson, Arizona.
Rosier, J.R., N.A. Ronan and D.K. Rosenberg. 2006. Post-Breeding Dispersal of Burrowing Owls in an Extensive California Grassland. American Midland Naturalist 155:162–167
Rowe, M.P., R.G. Coss, and D.H Owings. 1986. Rattlesnake Rattles and Burrowing Owl Hisses: A Case of Acoustic Batesian Mimicry. Ethology 72, 53-71.
Russell, S. 2002. West Nile Virus Killing U.S. Birds. San Francisco Chronicle, September 15, 2002, p. A3.
Sacramento Regional County Sanitation District (SRCSD). 2002. Case Study: Burrowing Owls.
Sacramento Regional County Sanitation District (SRCSD). 2004. Sacramento Regional Wastewater Treatment Plant Bufferlands Annual Report 2003.
Sacramento Regional County Sanitation District (SRCSD). 2006. Sacramento Regional Wastewater Treatment Plant Bufferlands Annual Report 2006.
204
Sales, L.P. and L. Parrott. 2024. The Owls are Coming: Positive Effects of Climate Change in Northern Ecosystems Depend on Grassland Protection. Science of the Total Environment, 907, p.167944. https://www.sciencedirect.com/science/article/pii/S0048969723065713
Salmon, T.P., W.P. Gorenzel, and W.J. Bentley. 1982. Aluminum Phosphide (Phostoxin) as a Burrow Fumigant for Ground Squirrel Control. Proceedings of the 10th Vertebrate Pest Conference, Monterey, California. Pp. 143-146.
San Bernardino County Museum (SBCM). 2001. Collection data provided by U.S. Bureau of Land Management records, Riverside Office.
San Diego. 1998. Final Multi Species Conservation Program MSCP Plan.
San Diego Museum of Natural History (SDMNH). 2001. Collection data provided by U.S. Bureau of Land Management records, Riverside Office.
San Diego Zoo Institute for Conservation Research (SDZICR). 2017. Burrowing Owl Conservation and Management Plan for San Diego County. San Diego Zoo Institute for Conservation Research, Escondido, CA.
San Diego Zoo Wildlife Alliance (SDZWA). 2018. Project Report 2018 Advancing Burrowing Owl Conservation in San Diego County through Mitigation Measures using Science and Adaptive Management. Authors Wisinski C.L, S. Marczak, R.R. Swaisgood and M. Merrick. Prepared for Metropolitan Airpark, LLC.
San Diego Zoo Wildlife Alliance (SDZWA). 2022. Metropolitan Airpark Project Report 2022 Advancing Burrowing Owl Conservation in San Diego County through Mitigation Measures using Science and Adaptive Management. Authors Wisinski C.L, S. Marczak, R.R. Swaisgood and M. Merrick. Prepared for Metropolitan Airpark, LLC.
San Joaquin Council of Governments (SJCOG). 2000. San Joaquin County Multi-Species Habitat Conservation and Open Space Plan.
San Marcos Foothills Association (SMFA). 2002. A Plan for the Preservation and Stewardship of San Marcos Foothills. www.sanmarcosfoothills.org
Santa Barbara Museum of Natural History (SBMNH). 2001. Collection data provided by Krista Fahy, Assistant Curator, Department of Vertebrate Zoology. Santa Barbara Museum of Natural History, Santa Barbara, California.
Santa Clara Valley Open Space Authority (SCVOSA). 2019. Seizing a Once-In-A-Generation Opportunity to Preserve San Jose's Last Great Landscape, Coyote Valley. https://news.openspaceauthority.org/blog/north-coyote-valley-acquisition
Santa Clara Valley Audubon Society (SCVAS). 2010. Haera Wildlife Conservation Bank.
Report.
Santa Clara Valley Habitat Agency (SCVHA). 2016. Santa Clara Valley Habitat Plan 2016 Burrowing Owl Breeding Season Surveys.
205
Santa Clara Valley Habitat Agency (SCVHA). 2024. Western Burrowing Owl Program Update.
Santa Clara Valley Habitat Plan, Public Advisory Committee.
Sapphos Environmental. 2013. Results of Habitat Assessment for Proposed Mitigation Lands of the Manzana Wind Energy Project, Kern County, California.
Sauer, J.R., S. Schwartz, and B. Hoover. 1996. The Christmas Bird Count. Version 95.1. U.S.
Geological Survey, Patuxent Wildlife Research Center, Laurel, Maryland.
Sauer, J.R., J.E. Hines, and J. Fallon. 2002. The North American Breeding Bird Survey, Results and Analysis 1966-2001. Version 2002.1. USGS Patuxent Wildlife Research Center, Laurel, Maryland.
Schoenherr, A.A., C.R. Feldsmith, and M.J. Emerson. 1999. Natural History of the Islands of California. California Natural History Guide.
Schreiber, R.W. 1970. Breeding Biology of Western Gulls (Larus occidentalis) on San Nicolas Island, California, 1968. Condor 72: 133-140.
Schulz, T.A. 1997. Observations, Resightings, and Encounters of Rehabilitated, Orphaned, and Relocated Burrowing Owls. Pp. 128-131 in Lincer, J.L. and K. Steenhof (editors). 1997. The Burrowing Owl, Its Biology and Management. Raptor Research Report Number 9.
Schwarzbach, S.E. 1991. The Role of Dicofol Metabolites in the Eggshell Thinning Response of Ring-Neck Doves. Archives of Environmental Contamination and Toxicology 20: 200-205.
Sequoia Riverlands Trust. 2014. Deed of Natural Conservation Easement.
Sharp, C.S. 1907. The Breeding Birds of Escondido. Condor. Volume IX, Number 3, May-June 1907, p. 87.
Sheffield, S.R. 1997a. Current Status, Distribution, and Conservation of the Burrowing Owl (Speotyto cunicularia) in Midwestern North America. Pages 399-407 in J.R. Duncan, D.H.
Johnson, and T.H. Nichols (editors). Biology and Conservation of Owls of the Northern Hemisphere. USDA Forest Service, General Technical Report NC-190. North Central Forest Experiment Station, St. Paul, Minnesota.
Sheffield, S.R. 1997b. Owls as Biomonitors of Environmental Contamination. Pages 383-398 in J.R. Duncan, D.H. Johnson, and T.H. Nichols (editors). Biology and Conservation of Owls of the Northern Hemisphere. USDA Forest Service, General Technical Report NC-190. North Central Forest Experiment Station, St. Paul, Minnesota.
Sheffield, S. 2021. Population Dynamics and Conservation of the Western Burrowing Owl (Athene cunicularia hypugaea) in North America: A 20-Year Update. https://www.researchgate.net/publication/350471917
Sheldon, H.H. 1909. Notes on some Birds of Kern County. Condor. Volume XI, Number 5, September-October 1909, p. 171.
Shuford, D.W. 1993. The Marin County Breeding Bird Atlas. A Distributional and Natural History of Coastal California Birds. California Avifauna Series 1. Point Reyes Bird Observatory. 206
Shyry, D.T., T.I. Wellicome, J.K. Schmutz, G.L. Erickson, D.L. Scobie, R.F. Russell, and R.G.
Martin. 2001. Burrowing Owl Population-Trend Surveys in Southern Alberta: 1991-2000. Journal of Raptor Research 35(4): 310-315.
Sierra Army Depot (SAD). 1992. Wildlife Management Plan for Sierra Army Depot, Herlong, California. Sierra Army Depot, Division of Environmental Management. Herlong, California.
Sissons, R.A, K.L. Scalise, and T.l. Wellicome. 2001. Nocturnal Foraging and Habitat Use by Male Burrowing Owls in a Heavily Cultivated Region of Southern Saskatchewan. Journal of Raptor Research 35:304-309.
Skirm, J. 1884. List of Birds of Santa Cruz, Cal. Ornithologist and Oologist. Vol. IX, No. 12, December 1884. pp. 149-150.
Small, A. 1974. The Birds of California. Winchester Press, New York, New York.
Smallwood, K.S. 2004. Comment letter to Winters City Council on Negative Declaration for the proposed Winters Highlands Subdivision, May 19, 2004.
Smallwood, K.S. 2008. Wind Power Company Compliance with Mitigation Plans in the Altamont Pass Wind Resource Area. Environmental & Energy Law Policy Journal 2: 229–285.
Smallwood, K.S. 2011. Comment on Mount Signal and Calexico Solar Farm Projects DEIR.
Submitted to County of Imperial Planning and Development Services Department, 21 December 2011.
Smallwood, K.S. 2012. Comment on Solar Gen 2 Array Project DEIR. Submitted to County of Imperial Planning and Development Services Department, 8 April 2012.
Smallwood, K.S. 2013a. Comparing Bird and Bat Fatality-Rate Estimates Among North American Wind-Energy Projects. Wildlife Society Bulletin 37: 19–33.
Smallwood, K.S. 2013b. 21 February 2013 comment letter to City of Davis Public Works Department on Sewer Trunk Rehabilitation Mitigated Negative Declaration.
Smallwood, K.S. 2013c. Comments on Imperial Valley Solar Company 2 Project DEIR.
Submitted to Imperial County Planning and Development Services February 18, 2013.
Smallwood, K.S. 2015a. Comments on Draft Desert Renewable Energy Conservation Plan DEIR/DEIS. Submitted to California Energy Commission February 25, 2015.
Smallwood, K.S. 2015b. Comments on Proposed Regulation for California Fish and Game Code Section 3503.5. Submitted to California Department of Fish and Wildlife, 22 September 2015.
Smallwood, K.S. 2021. Comments on the Draft Subsequent Environmental Impact Report for the Mulqueeney Ranch Wind Repowering Project.
Smallwood, K.S. 2022. Utility-Scale Solar Impacts to Volant Wildlife. Journal of Wildlife Management: e22216. https://doi.org/10.1002/jwmg.22216
207
Smallwood, K.S. 2022b. Comments to Riverside County Planning Department on Renaissance Ranch Commerce Center Draft Environmental Impact Report, 10 August 2022.
Smallwood, K.S. 2023a. Ecology and Recent Population Trend of Burrowing Owls in the Altamont Pass Wind Resource Area. 2023 Burrowing Owl Symposium, February 6-7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws- west.org/2023buowsymposium/abstracts?authuser=0
Smallwood, K.S. 2023b. Renewable Energy Impacts to Burrowing Owls. 2023 Burrowing Owl Symposium, February 6-7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws-west.org/2023buowsymposium/abstracts?authuser=0
Smallwood, K.S. 2023c. Comments to the City of Lathrop on Ashley Warehouse Project, 1 October 2023.
Smallwood, K.S. 2023d. Comments to the City of Desert Hot Springs on PODS Warehouse Initial Study and Mitigated Negative Declaration, 27 February 2023.
Smallwood, K.S. and D.A. Bell. 2020. Effects of Wind Turbine Curtailment on Bird and Bat Fatalities. Journal of Wildlife Management 84:684-696. DOI: 10.1002/jwmg.21844
Smallwood, K.S. and D.A. Bell. 2022. Ground Squirrel Abundance and Repeat Raptor Surveys at Vasco Caves Regional Preserve, 2006‒2019. Report to the East Contra Costa County Habitat Conservancy, Science and Research Grant Program.
Smallwood, K.S. and B. Karas. 2009. Avian and Bat Fatality Rates at Old-Generation and Repowered Wind Turbines in California. Journal of Wildlife Management 73: 1062–1071.
Smallwood, K.S. and M.L. Morrison. 2018. Nest-Site Selection in A High-Density Colony of Burrowing Owls. Journal of Raptor Research 52(4):454–470.
Smallwood, K.S. and M.L. Morrison. 2019. Efficacy of Mitigating Burrowing Owl Habitat Loss.
Smallwood, K.S. and L. Neher. 2004. Repowering the APWRA: Forecasting and Minimizing Avian Mortality without Significant Loss of Power Generation. PIER Energy-Related Environmental Research, CEC-500-2005-005. California Energy Commission: Sacramento, CA.
Smallwood, K.S. and L. Neher. 2009. Map-Based Repowering of the Altamont Pass Wind Resource Area Based on Burrowing Owl Burrows, Raptor Flights, and Collisions with Wind Turbines. Public Interest Energy Research–Environmental Area, Contract No. CEC-500-2009- 065. California Energy Commission: Sacramento, CA.
Smallwood, K.S. and N.L. Smallwood. 2023. Measured Effects of Anthropogenic Development on Vertebrate Wildlife Diversity. Diversity 2023, 15(10), 1037. https://doi.org/10.3390/d15101037
Smallwood, K.S. and C.G. Thelander. 2004. Developing Methods to Reduce Bird Mortality in the Altamont Pass Wind Resource Area. Final Report to the California Energy Commission, Public Interest Energy Research – Environmental Area, Contract No. 500-01-019. Sacramento, CA:
California Energy Commission.
208
Smallwood, K.S. and C.G. Thelander. 2008. Bird Mortality in the Altamont Pass Wind Resource Area, California. Journal of Wildlife Management 72: 215–223.
Smallwood, K., B. Wilcox, R. Leidy and K. Yarris. 1998. Indicators Assessment for Habitat Conservation Plan of Yolo County, California, USA. Environmental Management 22: 947–958.
Smallwood, K.S., C.G. Thelander, and L. Spiegel. 2003. Toward a Predictive Model of Avian Fatalities in the Altamont Pass Wind Resource Area. California Energy Commission, Sacramento, CA.
Smallwood, K.S., C.G. Thelander, M.L. Morrison and L.M. Rugge. 2007. Burrowing Owl Mortality in the Altamont Pass Wind Resource Area. The Journal of Wildlife Management 71(5):
1513-1524.
Smallwood, K.S., L. Neher and D.A. Bell. 2009a. Map-Based Repowering and Reorganization of a Wind Resource Area to Minimize Burrowing Owl and Other Bird Fatalities. Energies 2009, 2, 915-943. doi:10.3390/en20400915
Smallwood, K.S., L. Neher, D.A. Bell, J. DiDonato, B. Karas, S. Snyder, and S. Lopez. 2009b.
Range Management Practices to Reduce Wind Turbine Impacts on Burrowing Owls and Other Raptors in the Altamont Pass Wind Resource Area, California. Final Report to the California Energy Commission, Public Interest Energy Research – Environmental Area, Contract No.
CEC-500-2008-080. Sacramento, CA: California Energy Commission.
Smallwood, K.S., L. Rugge and M.L. Morrison. 2009c. Influence of Behavior on Bird Mortality in Wind Energy Developments: The Altamont Pass Wind Resource Area, California. Journal of Wildlife Management 73: 1082–1098.
Smallwood, K.S., L. Neher, J. Mount and R.C.E Culver. 2013. Nesting Burrowing Owl Density and Abundance in the Altamont Pass Wind Resource Area, California. Wildlife Society Bulletin 37(4):787–795.
Smallwood, K.S., L. Neher and D.A. Bell. 2017 Turbine Siting for Raptors: An Example from Repowering of the Altamont Pass Wind Resource Area. Chapter 7 in Wildlife and Wind Farms.
Smith, G.J. 1992. Toxicology and Pesticide Use in Relation to Wildlife: Organophosphorus and Carbamate Compounds. C.K. Smoley, Boca Raton, FL, pp. 3-18.
South, C.A. 1940. Winter Record of Burrowing Owl in Northern California. Condor. Volume XLII, Number 5, September-October 1940, p. 266.
South Valley Biology Consulting LLC (SVB). 2015-2019. 2014-2018 Annual Monitoring Reports for Coles Levee Ecosystem Preserve. Prepared for Aera Energy LLC.
Southern California Association of Governments (SCAG). 2019. Local Profiles. http://www.scag.ca.gov/DataAndTools/Pages/LocalProfiles.aspx
Southern California Association of Governments (SCAG). 2023. Draft Program Environmental Impact Report for the Southern California Association of Governments’ 2024–2050 Regional Transportation Plan/Sustainable Communities Strategy.
209
Sperry, C.C. 1941. Burrowing Owls Eat Spadefoot Toads. Wilson Bulletin 53: 45.
Stallcup, R. and R. Greenberg. 1974. Middle Pacific Coast Region Report. American Birds, Volume 28, Number 5, p. 945.
Stanton, E.J. and S. Teresa. 2007. Management of Burrowing Owl Habitat on Mitigation Lands.
Pages 132-136 in Proceedings of the California Burrowing Owl Symposium, November 2003.
Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No.
1. Stebbins, G.L. and D.W. Taylor. 1973. A Survey of the Natural History of the South Pacific Border Region, California. Prepared for the National Park Service, United States Department of the Interior. Institute of Ecology, University of California, Davis.
Stephens, F. 1895. Speotyto cunicularia obscura. Auk. Volume XII, October 1895, p. 372.
Stephens, F. 1902. Owl Notes from Southern California. Condor, Vol. IV, March 1902, p. 40.
Stephens, L.A. and C.C. Pringle. 1933. Birds of Marin County. Audubon Association of the Pacific, San Francisco, California.
Stone, R.D. and V.A. Sumida. 1983. The Kingston Range of California: A Resource Survey.
Publication No. 10, Environmental Field Program. University of California, Santa Cruz.
Stoner, E.A. 1922. Behavior of a Barn Owl in Captivity. Condor. Volume XXIV, Number 3, May- June 1922, p. 100.
Stoner, E.A. 1932a. Notes on the Western Burrowing Owl. Condor. Volume XXXIV, Number 5, September-October 1932, p. 228.
Stoner, E.A. 1932b. The Approximate Louse Population of a Burrowing Owl. Condor. Volume XXXIV, Number 5, September-October 1932, p. 230.
Stoner, E.A. 1933a. Some Subsistence Items of Western Burrowing Owls. Condor. Volume XXXV, Number 5, September-October 1933, p. 204.
Stoner, E.A. 1933b. Burrowing Owls Occupying Unusual Quarters. Condor. Volume XXXV, Number 1, January-February 1933, p. 36.
Storer, T.I. 1926. Range Extensions by the Western Robin in California. Condor. Volume XXVIII, Number 6, November-December 1926, p. 266.
Streator, C.P. 1886. List of Birds Observed in the Vicinity of Santa Barbara, Cal., During the Year 1885. Ornithologist and Oologist. Vol. XI, No. 5, May 1886, p. 67.
Streator, C.P. 1888. Notes on the Birds of the Santa Barbara Islands. Ornithologist and Oologist. Vol. XIII, No. 4, April 1888, pp. 52-54.
Streator, C.P. 1947. Birds of Santa Cruz County, California; A List. Santa Cruz, Santa Cruz Public Library.
210
Sullivan, B.L., C.L. Wood, M.J. Iliff, R.E. Bonney, D. Fink and S. Kelling. 2009. eBird: A Citizen- Based Bird Observation Network in the Biological Sciences. Biological Conservation 142: 2282- 2292.
Sumner, L. and J. S. Dixon. 1953. Birds and Mammals of the Sierra Nevada. University of California Press, Berkeley, California.
Sustain Environmental. 2007-2009. Grasslands Park Burrowing Owl Reserve Reports 2007, 2008, 2009.
Swarth, H.S. 1900. Avifauna of a 100-Acre Ranch. Condor. Volume 2, Number 1, January- February 1900, p. 16.
Swaisgood, R.R. and C.L. Wisinski. 2023. Engineering Better Burrows: Establishing Ground Squirrels and Improving Artificial Burrow Design. 2023 Burrowing Owl Symposium, February 6- 7, 2023, Riverside, CA. The Wildlife Society. https://sites.google.com/tws- west.org/2023buowsymposium/abstracts?authuser=0
Swaisgood, R.R., C. Wisinski, J.P. Montagne, S. Marczak, D.M. Shier, and L.A. Nordstrom. 2014. Project Report 2014: An Adaptive Management Approach to Recovering Burrowing Owl Populations and Restoring a Grassland Ecosystem in San Diego County. San Diego Zoo Institute for Conservation Research, Escondido, CA.
Talon Ecological Research Group. 2023. Status, Distribution, and Management of Burrowing Owls in Santa Clara County. Menzel, S., P. Higgins, R. Phillips, A. Bradshaw and G. Hube. 2023 Burrowing Owl Symposium. 70th Annual Meeting of The Wildlife Society, Western Section. February 6-7, 2023, Riverside, CA.
Taylor, M.F.J., K.F. Suckling and J.J. Rachlinski. 2005. The Effectiveness of the Endangered Species Act: A Quantitative Analysis. BioScience 55: 360–367.
Tenaza, R.R. 1967. Recent Records of Land Birds from South Farallon Island, California.
Condor. Volume 69, Number 6, November-December 1967, p. 579.
Thompson, C.D. and S.H. Anderson. 1988. Foraging Behavior and Food Habits of Burrowing Owls in Wyoming. Prairie Naturalist 20: 23-28.
Thomsen, L. 1971. Behavior and Ecology of Burrowing Owls on the Oakland Municipal Airport.
Condor. Volume 73, Number 2, Summer 1971, pp. 177-192.
Ting, I.P. and B. Jennings. 1976. Deep Canyon, a Desert Wilderness for Science. The Phillip L.
Boyd Deep Canyon Desert Research Center, Palm Desert. University of California, Riverside.
Townsend, C.H. 1887. Field Notes on the Mammals, Birds, and Reptiles of Northern California.
Extract from Proceedings of the U. S. National Museum. Washington.
Townsend, S.E. and C. Lenihan. 2007. Burrowing Owl Status in the Greater San Francisco Bay Area. Pages 60-69 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
211
Townsend, W.L. 1968. Birds Observed on San Nicolas Island, California. Condor 70: 266-268.
Trulio, L.A. 1994. The Ecology of a Population of Burrowing Owls at a Naval Air Station in Northern California. Dept. of the Navy. San Bruno, CA.
Trulio, L.A. 1995. Passive Relocation: A Method to Preserve Burrowing Owls on Disturbed Sites. Journal of Field Ornithology 66: 99-106.
Trulio, L.A. 1997. Strategies for Protecting Western Burrowing Owls (Speotyto cunicularia hypugaea) from Human Activities. Pp. 461-465 in Duncan, J.R., D.H. Johnson, and T.H.
Nicholls (editors). Biology and Conservation of Owls of the Northern Hemisphere. USDA Forest Service General Technical Report NC-190. St. Paul, Minnesota.
Trulio, L.A. 1997b. Burrowing Owl Demography and Habitat Use at Two Urban Sites in Santa Clara County, California. Pp. 84-89 in J.L. Lincer and K. Steenhof, editors. The Burrowing Owl, Its Biology and Management. Raptor Research Report No. 9.
Trulio, L.A. 1998a. The Burrowing Owl as an Indicator of CEQA Effectiveness and Environmental Quality in Silicon Valley. Environmental Monitor. Fall 1998. pp. 4-5.
Trulio, L.A. 1998b. Native Revival: Efforts to Protect and Restore the Burrowing Owl in the South Bay Area. Tideline. Volume 18, Spring 1988, pp. 1-3.
Trulio, L.A. 2002. Burrowing Owl Ecology and Demography Study: NASA Yearly Summary Report for 2001. Prepared Environmental Services Division, NASA/Ames Research Center, Moffett Federal Airfield, Moffett Field, CA.
Trulio, L.A. 2003. Burrowing Owl Habitat Disappearing in Silicon Valley. Silicon Valley 2002 Environmental Index. Silicon Valley Environmental Partnership. Pg. 28.
Trulio, L.A. and D.A. Chromczak. 2007. Burrowing Owl Nesting Success At Urban and Parkland Sites in Northern California. Pages 115-122 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Trulio, L.A. and P. Higgins. 2012. The Diet of Western Burrowing Owls in an Urban Landscape. Western North American Naturalist, 72(3), pp.348-356.
Trulio, L.A., D.A. Chromczak, P.G. Higgins, S. Menzel, C.M. Bossu and K. Ruegg. 2023.
Combining Genomic and Field Analyses to Reveal Migratory Status in a Burrowing Owl Population. Conservation Genetics, pp.1-11.
Tyler, J.G. 1913a. Some Birds of the Fresno District, California. Pacific Coast Avifauna, Number
9. Cooper Ornithological Club.
Tyler, J.G. 1913b. Notes on Some Fresno County Birds. Condor. Volume XV, Number 1, January-February 1913, p. 18.
U.S. Army. 2009. Final Environmental Impact Statement: Master Planned Redevelopment at Camp Parks. U.S. Army Garrison, Fort Hunter Liggett, CA.
212
United States Army Corps of Engineers (USACE). 1991. Environmental Assessment for the Closure and Realignment of Hamilton Army Airfield (HAAF), California. Prepared for Dept. of the Army Headquarters, Forces Command, Fort McPherson, Georgia.
United States Army Corps of Engineers (USACE). 1995. Draft Environmental Impact Statement, Hamilton Army Airfield Disposal and Reuse. Prepared by the U.S. Army Corps of Engineers, Sacramento District, with technical assistance from Jones & Stokes Associates, Inc.
United States Army Corps of Engineers (USACE). 1998. Final EIR for the Oakland Harbor Navigation Improvement (-50 Foot) Project. U.S. Army Corps of Engineers, San Francisco District. https://ceqanet.opr.ca.gov/Project/1997072051
United States Army Corps of Engineers (USACE). 2023. Regulatory In Lieu Fee and Bank Information Tracking System. https://ribits.ops.usace.army.mil/ords/f?p=107:2
United States Bureau of Land Management (USBLM). 2002. Athene cunicularia - Burrowing Owl. Bureau of Land Management records, Barstow Field Office.
United States Bureau of Land Management (USBLM). 2004. Final Environmental Impact Report and Statement for the West Mojave Plan. A Habitat Conservation Plan and California Desert Conservation Area Plan Amendment.
United States Bureau of Land Management (USBLM). 2012. El Centro Office Draft Environmental Impact Statement/Draft CDCA Plan Amendment Ocotillo Sol Project. U.S.
Department of the Interior, BLM/CA/ES-2012-009+1793, DES 20-12, DOI-BLM-CA-D000-2012- 0005-EIS. El Centro, California. https://ceqanet.opr.ca.gov/2012044003
United States Department of Agriculture (USDA). 1978. Big Sur Coastal Planning Unit. Final Environmental Statement. U.S. Forest Service, Los Padres National Forest.
United States Department of Agriculture (USDA) and United States Department of the Interior (USDI). 1996. North Fork Eel River watershed analysis. USDA Forest Service Pacific Southwest Region, Six Rivers National Forest and USDI Bureau of Land Management California State Office, Arcata Resource Area.
United States Environmental Protection Agency (USEPA). 1991. Environmental Fact Sheet for Carbofuran. Office of Pesticides and Toxic Substances, Washington, DC, pp. 3-34.
United States Environmental Protection Agency (USEPA). 2003. Vulnerable Listed (Endangered and Threatened) Species Pilot Project: Proposed Mitigations, Implementation Plan, and Possible Expansion. Draft Plan. USEPA, Office of Pesticide Programs. June 2023.
United States Fish and Wildlife Service (USFWS). 1995. Biological Information Report. Palm Springs Ground Squirrel Survey, August 11, 1995.
United States Fish and Wildlife Service (USFWS). 1998. Federal, State Cooperation Secure “Stay of Execution” for California Birds. USFWS Press Release, April 6, 1998.
United States Fish and Wildlife Service (USFWS). 2001. Final Environmental Impact Statement, Metro Air Park Project. https://www.fws.gov/policy/library/2001/01fr43265.html
213
United States Fish and Wildlife Service (USFWS). 2003. Status Assessment and Conservation Plan for the Western Burrowing Owl in the United States. Klute, D.S., L.W. Ayers, M.T. Green, W.H. Howe, S.L. Jones, J.A. Shaffer, S.R. Sheffield and T.S. Zimmerman.
U.S. Fish and Wildlife Service (USFWS). 2018. Joshua Tree Species Status Assessment. Dated July 20, 2018. 113 pp. + Appendices A–C.
United States Fish and Wildlife Service (USFWS). 2021. Birds of Conservation Concern 2021.
Migratory Bird Program.
United States Fish and Wildlife Service (USFWS). 2023. Conservation Plans Region Summary HCP. ECOS Environmental Conservation Online System.
https://ecos.fws.gov/ecp/report/conservation-plans-region-summary?region=8&type=HCP
United States National Park Service (USNPS). 1937. Check-List of the Birds of the National Parks. Department of the Interior, Washington, D.C. p. 29.
United States Navy (USN). 2002. Bird/Animal Strike Hazard Program.
Unitt, P. 1984. The Birds of San Diego County. San Diego Society of Natural History.
Unitt, P. 2002. San Diego County Bird Atlas: Breeding Bird Species Accounts. San Diego Natural History Museum.
University of California, Irvine (UCI). 1995. UC Irvine Ecological Preserve Draft Management Plan. http://conbio.bio.uci.edu/ep
University of California, Los Angeles (UCLA). 2001. Collection data provided by Kathy Molina, D.R. Dickey Bird and Mammal Collection Manager. University of California, Los Angeles.
University of California, Santa Barbara (UCSB). 2001. Collection data provided by Mark Holmgren, Associate Director. Museum of Systematics and Ecology, University of California, Santa Barbara.
University of California, Santa Cruz (UCSC). 2001. Collection data provided by Jeff Davis, Senior Museum Scientist. Museum of Natural History Collections, University of California, Santa Cruz.
University of Washington Burke Museum (UWBM). 2001. Collection data provided by Robert Faucett, Collections Manager, Ornithology. Burke Museum, University of Washington.
URS. 2002. Natural Environment Study/Biological Assessment, Merced Campus Parkway.
Prepared for Merced County Department of Public Works, Merced, California, and Caltrans, District 10, Stockton, California.
Van Denburgh, J. 1899. Notes on Some Birds of Santa Clara County, California. Proc. Amer.
Phil. Soc. 38: 157-180.
Van Dyke, T.S. 1888. Southernmost California. In J. Muir (editor). Picturesque California and the Region West of the Rocky Mountains, from Alaska to Mexico. Republished as West of the Rocky Mountains, by Running Press, Philadelphia, PA, 1976. 214
Van Mantgem, E.F. 2002. Colonel Allensworth State Historic Park Burrowing Owl Quarterly Report, July 15, 2002. Unpublished report.
Van Rossem, A. 1914. Notes from the San Bernardino Mountains. Condor. Volume XVI, Number 3, May-June 1914, pp. 145-146.
Voous, K H. 1988. Owls of the Northern Hemisphere. M.I.T. Press, Cambridge, Massachusetts.
Walker C.H. 1983. Pesticides and Birds — Mechanisms of Selective Toxicity. Agriculture, Ecosystems & Environment, Volume 9, Issue 2. Pages 211-226. ISSN 0167-8809, https://doi.org/10.1016/0167-8809(83)90042-7.
Walston, L.J., Jr., K.E. Rollins, K.E. LaGory, K.P. Smith and S.A. Meyers. 2016. A Preliminary Assessment of Avian Mortality at Utility-Scale Solar Energy Facilities in the United States.
Renewable Energy, 92, 405–414.
https://doi.org/10.1016/j.renene.2016.02.041
Waples, R.S. 1991. Definition of "Species" Under the Endangered Species Act: Application to Pacific Salmon. NOAA (National Oceanic and Atmospheric Administration) Technical Memorandum NMFS (National Marine Fisheries Service) F/NWC-194, Northwest Fisheries Science Center, Seattle.
Warnock, R. 1996. Spatial, Temporal and Turnover Dynamics of Burrowing Owls in the Extensively Fragmented Grasslands of Saskatchewan. M.S. Thesis. University of Regina, Regina, Saskatchewan. 112 pages.
Warnock, R. 1997. Is Habitat Fragmentation a Factor in the Decline of the Burrowing Owl in Saskatchewan? Blue Jay. Vol. 55, No. 4: 222-228.
Warnock, R.G., and P.C. James. 1997. Habitat Fragmentation and Burrowing Owls (Speotyto cunicularia) in Saskatchewan. Pages 477-486 in J.R. Duncan, D.H. Johnson, and T.H. Nichols (editors). Biology and Conservation of Owls of the Northern Hemisphere. USDA Forest Service, General Technical Report NC-190. North Central Forest Experiment Station, St. Paul, Minnesota.
Warrick, S F. 1982. The Natural History of the UC Santa Cruz Campus. Publication No. 11, Environmental Field Program. University of California, Santa Cruz.
Wauer, R.H. 1962. A Survey of the Birds of Death Valley. Condor. Volume 64, Number 3, May- June 1962, pp. 220-226.
Wauer, R.H. 1964. Ecological Distribution of the Birds of the Panamint Mountains, California.
Condor. Volume 66, Number 4, July-August 1964, p. 290.
Weathers, W.W. 1983. Birds of Southern California’s Deep Canyon. University of California Press, Berkeley, Los Angeles, London.
Wedgwood, J.A. 1976. Burrowing Owls in South-Central Saskatchewan. Blue Jay 34: 26-44.
215
Wedgwood, J.A. 1978. The Status of the Burrowing Owl in Canada. Prepared for the Committee on the Status of Endangered Wildlife in Canada. Canadian Wildlife Service, Ottawa.
Wellicome, T.I. 1997. Status of the Burrowing Owl (Speotyto cunicularia hypugaea) in Alberta.
Wildlife Status Report No. 11. Alberta Environmental Protection, Wildlife Management Division, Edmonton, Alberta.
Wellicome, T.I. and E.A. Haug. 1995. Second Update of Status Report on the Burrowing Owl (Speotyto cunicularia) in Canada. Committee on the Status of Endangered Wildlife in Canada, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario.
Wellicome, T.I. and G L. Holroyd. 2001. The Second International Burrowing Owl Symposium:
Background and Context. Journal of Raptor Research 35(4): 269-273.
Wellicome, T.I., G L. Holroyd, K. Scalise and E.R. Wiltse. 1997. The Effects of Predator Exclusion and Food Supplementation on Burrowing Owl (Speotyto cunicularia) Population Change in Saskatchewan. Pages 487-497 in J.R. Duncan, D.H. Johnson and T.H. Nicholls (editors). Biology and Conservation of Owls of the Northern Hemisphere: Second International Symposium. USDA, For. Serv. Gen. Tech. Rep. NC-1901 North Central For. Exp. Station.
West, E.W. 1973. Indian Valley Project. Wildlife ecology and management study of Indian Valley Reservoir, California. Yolo County Flood Control & Water Conservation District.
Western Environmental Law Center (WELC). 2002. Center for Biological Diversity and California/Nevada Desert Committee of the Sierra Club Comments on the Draft Environmental Impact Report/Environmental Impact Statement and Draft Habitat Conservation Plan for the Imperial Irrigation District Water Conservation and Transfer Project. Submitted to Bureau of Reclamation, Phoenix, AZ, and Imperial Irrigation District, Imperial, CA.
Western Foundation of Vertebrate Zoology (WFVZ). 2001. Collection data provided by Rene Corado, Collections Manager. Western Foundation of Vertebrate Zoology, Camarillo, California.
Western Riverside County regional Conservation Authority. 2021. Western Riverside County Multiple Species Habitat Conservation Plan Annual Report, 2021.
Westervelt Ecological Services. 2009-2023. Burke Ranch Conservation Bank 2008-2022 Annual Reports.
Westervelt Ecological Services. 2013. Summary of Wildlife Observations on the Proposed Dutchman Creek Conservation Bank Property.
Westervelt Ecological Services. 2014. Exhibit H-1 Biological Resources Survey Summary Report.
WRA. 2013-2020. 2012-2019 Annual Monitoring Reports Elsie Gridley Mitigation Bank, Solano County, California. Prepared for Wetland Resources LLC.
Wheeler, C.M., J.R. Douglas, and F.C. Evans. 1941. The Role of the Burrowing Owl and the Sticktight Flea in the Spread of Plague. Science, September 12, 1941, p. 560-561.
216
Whitney, K.L. and K.E. Kudrak. 1997. Burrowing Owl. Draft report submitted to Vandenberg Air Forde Base.
Widdicombe, J.H. 2007. Nesting Burrowing Owls in Solano and Yolo Counties, California, 2000- 2005. Pages 52-59 in Proceedings of the California Burrowing Owl Symposium, November 2003. Institute for Bird Populations and Albion Environmental, Inc. Bird Populations Monographs No. 1.
Wiemeyer, S.N., J.W. Spann, C.M. Bunck, and A.J. Krynitsky. 1989. Effects of Kelthane on Reproduction of Captive Screech Owls. Environmental Toxicology and Chemistry 8: 903-913.
Wilder, H.E. 1916. Some Distributional Notes on California Birds. Condor. Volume XVIII, Number 3, May-June 1916, p. 128.
Wildlands. 2011. Alta Oak Creek Mojave Mitigation Preserve, Kern County, California.
Wildlands. 2012. Cuddeback Lake Preserve Habitat Management Lands Acquisition Package for the Alta Oak Creek Mojave Project Infill. CDFG Incidental Take Permit No. 2081-2011-009- 04, San Bernardino County, California.
Wildlife Research Institute (WRI). 2009. WRI Burrowing Owl Update #5.
Wiley, J.W. 1975. The Nesting and Reproductive Success of Red-Tailed Hawks and Red- Shouldered Hawks in Orange County, California, 1973. Condor. Volume 77, Number 2, Summer 1975, p. 133.
Wilkerson, R.L. and R.B. Siegel. 2010. Assessing Changes in the Distribution and Abundance of Burrowing Owls in California, 1993-2007. Bird Populations 10:1-36.
Wilkerson, R.L. and R.B. Siegel. 2011. Distribution and Abundance of Western Burrowing Owls (Athene cunicularia hypugaea) in Southeastern California. The Southwestern Naturalist 56(3):378–384.
Willett, G. 1908. Summer Birds of the Upper Salinas Valley and adjacent foothills. Condor.
Volume X, Number 4, July-August 1908, p. 138.
Willett, G. 1910. A Summer Trip to the Northern Santa Barbara Islands. Condor. Volume XII, Number 5, September-October 1910, p. 172.
Willett, G. 1912. Birds of the Pacific Slope of Southern California. Pacific Coast Avifauna Number 7. Cooper Ornithological Club, Hollywood, California, 1912. p. 53.
Wilson, I.D. 1945. Birds of the Kettleman Hills Area, California. Condor. Volume 47, Number 4, July-August 1945, pp. 149-153.
City of Winters (Winters). 2006. Winters Highlands Environmental Impact Report. https://www.cityofwinters.org/DocumentCenter/View/1074/Winters-Highlands-Environmental- Impact-Report
Wisinski, C.L., S.M. Hennessy, J.P. Montagne, S. Marczak, M. Stevens, J. Hargis, D.M. Shier, R.R. Swaisgood and L.A. Nordstrom. 2016. Project Report 2016: An Adaptive Management 217
Approach to Recovering Burrowing Owl Populations and Restoring a Grassland Ecosystem in San Diego County. San Diego Zoo Institute for Conservation Research, Escondido, CA.
Wisinski, C. L., S. Marczak, S. M. Hennessy, M. Stevens, S. Perez, D. Angel, K. Hines, R. R.
Swaisgood, and L. A. Nordstrom. 2020a. Project Report 2019: Advancing Burrowing Owl Conservation in San Diego County through Mitigation Measures using Science and Adaptive Management. San Diego Zoo Institute for Conservation Research, Escondido, CA.
Wisinski, C. L., S. Marczak, S. M. Hennessy, M. Stevens, S. Perez, D. Angel, K. Hines, R. R.
Swaisgood, and L. A. Nordstrom. 2020b. Project Report 2019: Advancing Burrowing Owl Conservation in San Diego County through Mitigation Measures using Science and Adaptive Management. San Diego Zoo Institute for Conservation Research, Escondido, CA.
Wisinski, C.L., S.M. Hennessy, S.A. Marczak, D. Mayer, T. Nelson, L.A. Nordstrom, K. Rice, H.
Sin, M.T. Stevens and R.R. Swaisgood. 2021. Building a New Burrowing Owl Subpopulation Through Collaboration and Translocation. Ecology and Conservation of Birds. The Wildlife Society.
Wisinski, C.L., S. Marczak, R.R. Swaisgood and M. Merrick. 2022. Metropolitan Airpark Project Report 2022: Advancing Burrowing Owl Conservation in San Diego County through Mitigation Measures using Science and Adaptive Management. San Diego Zoo Wildlife Alliance, Escondido, CA.
Wisinski, C.L., S. Marczak, R.R. Swaisgood and M. Merrick. 2023. Burrowing Owl Translocation Report 2023. San Diego Zoo Wildlife Alliance, Escondido, CA.
Wyllie, I. 1995. Potential Secondary Poisoning of Barn Owls by Rodenticides. Pesticide Outlook 5: 19-25.
Yolo County. 2023. Crop Statistics. https://www.yolocounty.org/government/general- government-departments/agriculture-cooperative-extension/agriculture-and-weights- measures/crop-statistics
Yolo Habitat Conservancy (YHC). 2017. Yolo HCP/NCCP Public Review Draft, May 2017.
Appendix A, Covered Species Accounts.
York, M., D.K. Rosenberg, and K.K. Strum. 2002. Diet and Food-Niche Breadth of Burrowing Owls (Athene cunicularia) in the Imperial Valley, California. Western North American Naturalist 62: 280-287.
Zarn, M. 1974a. Burrowing Owl. U.S. Department of the Interior, Bureau of Land Management.
Tech. Note T-N-250, Denver, Colorado, 25pp.
Zarn, M. 1974b. Habitat Management Series for Unique or Endangered Species. Report no. 12:
Osprey (Pandion haliaetus carolinensis). U.S. Department of the Interior, Bureau of Land Management. Technical note T-N-254. 41 pp.
Zeiner, D.C., Jr., W.F. Laudenslayer, K.E. Mayer, and M. White (editors). 1990. California’s Wildlife. Volume II. Birds. California Statewide Wildlife Habitat Relationships Systems.
Sacramento, California: California Department of Fish and Game. 732 pp.
218
Personal Communication Sources
Chris Alford, Alford Environmental, consultant for Yolo Habitat Conservancy
Jake Aucelluzzo, CDFW Unit Wildlife Biologist, Yolo Bypass Wildlife Area
John H. Barclay, Albion Environmental, Inc., Santa Cruz, CA
Jack Bath, Ph.D., Professor of Zoology, California State Polytechnic University, Pomona, CA
Doug Bell, Ph.D., Wildlife Program Manager, East Bay Regional Park District
Peter Bloom, Western Foundation of Vertebrate Zoology, Camarillo, CA
Craig Breon, Executive Director, Santa Clara Valley Audubon Society, Cupertino, CA
Nikolle Brown, Wildlife Biologist, Clovis, CA
Debra Chromczak, Burrowing Owl Specialist, Mountain View, CA
Charlie Collins, Biological Sciences Professor, California State University, Long Beach, CA
Chris Conard, Natural Resource Specialist with Sacramento Bufferlands
Michael Connor, Executive Director, Desert Tortoise Preserve Committee, Riverside, CA
Daniel Cooper, Director of Bird Conservation, Audubon California, Los Angeles, CA
Penelope Delevoryas, Wildlife Biologist, Shoreline Park, Mountain View, CA
Dr. David DeSante, Biologist/Executive Director, Institute for Bird Populations, Point Reyes Station, CA
Joseph DiDonato, Wildlife Program Manager, East Bay Regional Park District, Oakland, CA
Linda Dye, National Park Service, Channel Islands National Park
Jim Estep, Estep Environmental Consulting, consultant for Yolo Habitat Conservancy
Abigail Fateman, Executive Director, East Contra Costa County Habitat Conservancy
Jennifer Gervais, Assistant Professor of Research, Department of Forest, Range and Wildlife Sciences, Utah State University, Logan, UT
Daniel Guthrie, Professor of Biology, Claremont McKenna College; President, Pomona Valley Audubon Society, Claremont, CA
Rob Hansen, Hansen Biological Consulting, Visalia, CA
Roger Higson, local active birder, Blythe, CA
219
Geoff Holroyd, Research Scientist, Canadian Wildlife Service, Edmonton, Alberta
Robert Huddleston, Biologist, California Department of Fish and Game, Mendota Wildlife Area, CA
Grainger Hunt, Santa Cruz Predatory Bird Research Group, Santa Cruz, CA
Jeff Kidd, Western Foundation of Vertebrate Zoology, Camarillo, CA
Chuck Klein, Wildhorse Golf Course Manager
Kim Kreitinger, Biologist, Endangered Species Recovery Program, California State University, Fresno, CA
Brian Latta, Santa Cruz Predatory Bird Research Group, Santa Cruz, CA
Jeff Lincer, Research Director, Wildlife Research Institute, San Diego, CA
Janet Linthicum, Santa Cruz Predatory Bird Research Group, Santa Cruz, CA
John McNerney, Natural Resource Specialist, City of Davis
Richard Montijo, Senior Biologist, AMEC Earth and Environmental, Santa Barbara, CA
Stephen Myers, Wildlife Biologist, AMEC Earth and Environmental, Riverside, CA
Pamela Nieberg, Co-founder Burrowing Owl Preservation Society
Ed Pandolfino, former board member of Institute for Bird Populations, Western Field Ornithologists, Sierra Foothills Audubon Society, and San Francisco Bay Bird Observatory
Robin Panza, Section of Birds, Carnegie Museum of Natural History, Pittsburgh, PA
Catherine Portman, Burrowing Owl Preservation Society, Woodland, CA
Shawn Smallwood, Ph.D., Biologist, Davis, CA
Glenn Stewart, Ph.D., Professor of Zoology, California State Polytechnic University, Pomona, CA
Lynne Trulio, Associate Professor, Department of Environmental Studies, San Jose State University, San Jose, CA
Philip Unitt, Collection Manager, Department of Birds and Mammals, San Diego Natural History Museum, San Diego, CA
Brian Walton, Santa Cruz Predatory Bird Research Group, Santa Cruz, CA
Dennis Warren, San Luis National Wildlife Refuge, Los Banos, CA
220
Colleen Wisinski, Conservation Program Manager, Burrowing Owl Recovery Program, San Diego Zoo Wildlife Alliance
APPENDIX P
ANALYSIS OF EFFECTS ON THE NATOMAS BASIN
HABITAT CONSERVATION PLAN REPORT
July 19, 2006
Greenbriar Development Project
Sacramento, California
Analysis of Effects on the
Natomas Basin Habitat Conservation Plan Report
Prepared for:
City of Sacramento
Environmental Planning Services
Prepared for:
City of Sacramento
Environmental Planning Services
City Hall Annex
915 I Street, Suite 300
Sacramento, CA 95814
Contact:
Tom Buford
Development Services Department
Environmental Planning Services
916/808-7931
Greenbriar Development Project
Sacramento, California
Analysis of Effects on the
Natomas Basin Habitat Conservation Plan Report
05110011.01
Prepared by:
EDAW
2022 J Street
Sacramento, CA 95814
Contact:
John C. Hunter, Ph.D.
Senior Ecologist
916/414-5800
July 19, 2006
Greenbriar Development Project EDAW
City of Sacramento i Analysis of Effects on the Natomas Basin HCP
TABLE OF CONTENTS
Chapter/Section Page
EXECUTIVE SUMMARY .....................................................................................................................................iv ES.1 Introduction .............................................................................................................. .......................iv ES.2 Overview of Greenbriar Project ......................................................................................................iv ES.3 Summary of Findings .......................................................................................................................v ES 3.2 Effects on the Conservation Strategy of the NBHCP.................................................................... vii ES 3.3 Effects on Attainment of NBHCP Goals and Objectives ................................................................ix ES.4 Summary ................................................................................................................... ......................xi 1 INTRODUCTION ................................................................................................................. .................. 1-1
1.1 Introduction ............................................................................................................... ................... 1-1
1.2 Overview of Greenbriar Project ............................................................................................. ...... 1-1
1.3 Use of th is Document ................................................................................................................... 1-4
1.4 Organization ............................................................................................................... .................. 1-5 2 EVALUATION APPROACH .......................................................................................................... ...... 2-1
2.1 Overview ................................................................................................................... ................... 2-1
2.2 Description of Greenbriar Project ................................................................................................ 2-1
2.3 Methodology for Analyzing Alterations of Populations and Habitats ......................................... 2-4
2.4 Basis for Interpretations of Effects on Covered Species ............................................................ 2-14
2.5 Basis for Interpretations of Eff ects on NBHCP Conservation Strategy..................................... 2-15
2.6 Basis for Interpretations of Eff ects on HCP Goals and Objectives............................................ 2-15 3 GREENBRIAR PROJECT’S ALTERATION OF POPULATION AND HABITAT ATTRIBUTES 3-1
3.1 Construction-Related Effects on Survival and Reproduction....................................................... 3-1
3.2 Zones with Huma n-Wildlife Conflicts .........................................................................................3 - 2
3.3 Habitat Acreage in the Natomas Basin....................................................................................... .. 3-4
3.4 Habitat Quality in the Natomas Basin .......................................................................................... 3-7
3.5 Connectivity of Habitat in the Natomas Basin ........................................................................... 3-10
3.6 Connectivity of Existing TNBC Reserves.................................................................................. 3-2 7
3.7 Habitat Value of Existing TNBC Reserves ................................................................................ 3-28
3.8 Water Availability at TNBC Reserves ....................................................................................... 3-29
3.9 Opportunities to Establish Additional TNBC Reserves ............................................................. 3-30 4 POTENTIAL EFFECTS OF THE GREENBRI AR PROJECT ON COVERED SPECIES ................. 4-1
4.1 Giant Gart er Snake ....................................................................................................................... 4-1
4.2 Northwestern Pond Turtle ................................................................................................... ......... 4-8
4.3 Swains on’s Hawk ....................................................................................................................... 4-12
4.4 Burrowing Owl.............................................................................................................. ............. 4-19
4.5 Loggerhead Shrike .......................................................................................................... ........... 4-24
4.6 Tricolored Blackbird .................................................................................................................. 4-28
4.7 White-Faced Ibis ........................................................................................................... ............. 4-32
4.8 Aleutian Ca nada Goose .............................................................................................................. 4-34
4.9 Bank Swallow............................................................................................................... .............. 4-37
4.10 Valley Elderbe rry Longhorn Beetle ........................................................................................... 4-40
4.11 California Tiger Salamander ............................................................................................... ....... 4-42
4.12 Western Spadefoot Toad .................................................................................................... ........ 4-43
4.13 Vernal Pool Fairy Shrimp.................................................................................................. ......... 4-45
4.14 Vernal Pool Tadpole Shrimp................................................................................................ ...... 4-46
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP ii City of Sacramento
TABLE OF CONTENTS
(continued)
Chapter/Section Page
4.15 Midvalley Fairy Shrimp .................................................................................................... ......... 4-48
4.16 Covered Plant Species ..................................................................................................... ........... 4-49 5 POTENTIAL EFFECTS ON THE CONSERVA TION STRATEGY OF THE NBHCP....................... 5-1
5.1 Basis for 0.5 To 1 Mitigation Ratio........................................................................................ ...... 5-1
5.2 Preparation of Site Specific Management Plans .......................................................................... 5-2
5.3 Buffers within Reserve Lands ............................................................................................... ....... 5-2
5.4 Connectivity ............................................................................................................... .................. 5-3
5.5 Foraging Habitat........................................................................................................... ................ 5-3
5.6 Minimum Habitat Block Size Requirements................................................................................ 5-4
5.7 Effectiveness of the Conserva tion Strategy of the NBHCP ......................................................... 5-5 6 POTENTIAL EFFECTS OF THE GREENBRIAR PROJECT ON NBHCP GOALS AND OBJECTIVES .................................................................................................................................................... 6-1
6.1 Overa ll Goals.............................................................................................................. .................. 6-2
6.2 Overall Objectives......................................................................................................... ............... 6-5
6.3 Wetland Species/Habitat Go als and Objectives ........................................................................... 6-7
6.4 Upland Species/Habitat Go als and Objectives ............................................................................. 6-8 7 CUMULATIVE EFFECTS .............................................................................................................................. 7-1
7.1 Analysis of Cumulativ e Effects under NEPA .............................................................................. 7-1
7.2 Cumulative E ffects under ESA .................................................................................................... 7-9 8 REFERE NCES................................................................................................................................................... 8-1
Appendix
A Assessment of Avoidance and Minimization of Cons truction-related Effects and Human-Wildlife Conflicts B Change in Natomas Basin Land Cover in 2001–2004
Exhibits
1 Location of Greenbriar Project in the Natomas Basin.......................................................................... ..... 1-2 2 Project Boundary and Conservation Easeme nt Locations at the Greenbriar Site...................................... 1-3 3 Quality and Availability of Swainson’s Hawk Foragi ng Habitat at the Project and Mitigation Sites..... 3-11 4 Total Swainson’s Ha wk Foraging Habitat....................................................................................... ........ 3-12 5 Canals and Drains of Natomas Basin ........................................................................................... ........... 3-15 6 Location of TNBC Reserves .................................................................................................... ............... 3-32
Greenbriar Development Project EDAW
City of Sacramento iii Analysis of Effects on the Natomas Basin HCP
TABLE OF CONTENTS
(continued)
Page
Tables
2-1 Species Habitat-La nd Cover Relationships ............................................................................................... 2-8 2-2 Habitat Type Acreages Used in Analyses of Effects on Swainson’s Hawk Foraging Habitat................ 2-10 2-3 Habitat Quality and Harvest Months for Swainson’ s Hawk Foraging Habitats in the Natomas Basin1. 2-11 2-4 Relationships between Applicable NBHCP Goals and Objectives and Attributes Potentially Affected by the Greenbriar Project............................................................................................. ............. 2-16 3-1 Land Cover Acreages of Greenbriar Project ................................................................................. ............ 3-4 3-2 Change in Land Cover Acreage Because of Natomas Basin HCP and Greenbriar Project....................... 3-6 3-3 Change in Habitat Acreage Because of Natomas Basin HCP and Greenbriar Project.............................. 3-7 4-1 Change in Acreage of Giant Garter Snake Hab itat at Project Sites and in the Natomas Basin................. 4-4 4-2 Change in Acreage of Northwestern Pond Turtle Ha bitat at Project Sites and in the Natomas Basin.... 4-10 4-3 Change in Acreage of Swainson ’s Hawk Foraging Habitat at Project Sites and in the Natomas Basin . 4-15 4-4 Change in Acreage of Burrowing Owl Habitat at Project Sites and in the Natomas Basin .................... 4-21 4-5 Change in Acreage of Loggerhead Shrike Habita t at Project Sites and in the Natomas Basin ............... 4-26 4-6 Change in Acreage of Tricolored Blackbird Nesting Habitat at Project Sites and in the Natomas Basin....... 4-29 4-7 Change in Acreage of Tricolored Blackbird Foraging Habitat at Project Sites and in the Natomas Basin..... 4-30 4-8 Change in Acreage of White-faced Ibis Habita t at Project Sites and in the Natomas Basin................... 4-33 4-9 Change in Acreage of Aleutian Canada Goose Hab itat at Project Sites and in the Natomas Basin........ 4-36 4-10 Change in Acreage of Bank Swallow Habitat at Project Sites and in the Natomas Basin ...................... 4-38 4-11 Primary Habitats and Distribution of Plant Species Covered by the NBHCP ........................................ 4-50 7-1 Potential Loss of Agricultural and Natural Ve getation Due to Additional Proposed Projects.................. 7-7
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP iv City of Sacramento
EXECUTIVE SUMMARY
ES.1 INTRODUCTION
This Analysis of Effects on the Natomas Basin Habitat Conservation Plan Report (effects analysis) (EDAW 2006) is an evaluation of the effects on each species covered by the Natomas Basin Habitat Conservation Plan (NBHCP), on the conservation strategy of the NBHCP, on specific conservation measures, and consequently on attainment of the NBHCP’s goals and objectives as a result of implementing the proposed Greenbriar project. The U.S. Fish & Wildlife Service (Service) and the California Department of Fish & Game (Department) approved the NBHCP in the summer of 2003. The NBHCP establishes the overall conservation program for the development of a 17,500 acre-portion of the Natomas Basin. The Greenbriar site is located within the boundaries of the NBHCP plan area, but is not within an area permitted for development. This Effects Analysis is being released for public review in conjunction with the Greenbriar Development Project Sacramento, California: Draft Environmental Impact Report (DEIR) (EDAW 2006) because the EIR contains an evaluation of the Greenbriar project’s effects on biological resources for purposes of CEQA review, as well as the evaluation of the project’s effects on the NBHCP.
The Effects Analysis is organized in the following way:
► Section 1, Introduction
► Section 2, Evaluation Approach
► Section 3, Greenbriar Project’s Alteration of Population and Habitat Attributes ► Section 4, Potential Effects of the Greenbriar Project on Covered Species ► Section 5, Potential Effects on the Conservation Strategy of the NBHCP ► Section 6, Potential Effects of the Greenbriar Project on NBHCP Goals and Objectives ► Section 7, Cumulative Effects
► Appendix A, Consistency of Greenbriar Project and NBHCP Measures to Reduce Construction-related Effects and Human-Wildlife Conflicts
► Appendix B, Change in Natomas Basin Land Cover in 2001–2004 ES.2 OVERVIEW OF GREENBRIAR PROJECT
As currently proposed, the Greenbriar project would:
► Develop 546 acres at the Greenbriar site;
► Avoid and preserve an on-site corridor (of 31 acres) along Lone Tree Canal; ► Create or enhance, preserve, and manage in perpetuity two proposed off-site reserves — the Natomas 130 and Spangler properties (with a combined acreage of 266 acres).
As designed, the proposed project includes a package of measures to avoid, minimize, and mitigate impacts from the proposed development. In addition, the City of Sacramento, through the CEQA process, has proposed mitigation measures to reduce further the adverse effects of the proposed project. (Throughout this Effects
Greenbriar Development Project EDAW
City of Sacramento v Analysis of Effects on the Natomas Basin HCP Analysis, “mitigation” refers to the measures proposed by the City of Sacramento in the Draft EIR for the Greenbriar project [City of Sacramento July 2006].) With the DEIR mitigation, the project’s avoidance, minimization, and mitigation measures include:
► Avoidance of a 31 acre (250-foot wide) corridor along Lone Tree Canal; ► Measures to reduce or offset effects on the Lone Tree Canal corridor including barriers/fencing, creation of marsh habitat along the canal corridor, design of canal crossings to minimize obstacles to giant garter snake movement, and an assurance that aquatic habitat would be maintained in this section of the canal; ► Funding to manage the Lone Tree Canal corridor in perpetuity; ► Measures to avoid and minimize construction-related effects on covered species; and ► Creation or enhancement, preservation, and management in perpetuity of 315 acres of high quality habitat in addition to the corridor conserved along Lone Tree Canal.
ES.3 SUMMARY OF FINDINGS
To evaluate the proposed project’s effects on the effectiveness of the NBHCP, this effects analysis performed an extensive analysis of the project’s potential effects on the future condition of the Natomas Basin. This analysis used the 2001 land cover data that represents baseline conditions of the NBHCP, and also considered 2001–2004 changes in land cover, and 2005 conditions. Interpretations of the project’s effects on the NBHCP were based on the sum of anticipated effects on the viability of populations of covered species using the Natomas Basin, on the effectiveness of the NBHCP’s conservation strategy, and on attainment of the goals and objectives of the NBHCP.
Although the proposed project would cause a variety of adverse and beneficial effects, overall, the proposed project (with the DEIR mitigation) would not reduce the viability of covered species, the efficacy of the NBHCP conservation strategy, or adversely affect attainment of the NBHCP goals and objectives. In part, it would have this outcome because its conservation strategy includes a substantial investment in the creation, enhancement, and management in perpetuity of high quality habitat on the preserved land, and in the avoidance, minimization, and mitigation of effects on the Lone Tree Canal corridor. For most covered species, the increased habitat values on preserved lands offset the habitat values lost as a result of development at the Greenbriar site, and thus prevent a net loss in resources in the Natomas Basin for these species. The conservation of the Lone Tree Canal corridor, while costly and resulting in a small reserve that will be costly to manage, is essential for maintaining connectivity of aquatic habitat and movement of giant garter snakes between the southern and central Natomas Basin; without this connectivity, the effectiveness of the NBHCP’s conservation strategy would be reduced.
The project’s adverse and beneficial effects on the viability of populations of covered species using the Natomas Basin, on the effectiveness of the NBHCP’s conservation strategy, and on attainment of the goals and objectives of the NBHCP are summarized in the following sections of text.
ES 3.1 E FFECT ON POPULATION VIABILITY OF COVERED SPECIES The Greenbriar project would not affect five of the 15 animal species covered by the NBHCP: California tiger salamander, western spadefoot toad, vernal pool fairy shrimp, vernal pool tadpole shrimp, and midvalley fairy shrimp. None of these vernal pool-associated species are known from the vicinity of the Greenbriar or proposed reserve sites, nor does suitable habitat occur in the vicinity of these sites.
The project is also unlikely to affect valley elderberry longhorn beetle (VELB) because VELB is not known from the vicinity of the Greenbriar or proposed reserve sites, and riparian habitat that might contain elderberry bushes
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP vi City of Sacramento is only present at and in the vicinity of the proposed Natomas 130 reserve; also, in the future, riparian habitat may recover and persist in the proposed reserve along Lone Tree Canal; preservation of these sites was considered unlikely to benefit VELB.
The Greenbriar project would cause a variety of beneficial and adverse effects on populations of nine species covered by the NBHCP. For these species, the overall effect on population viability is summarized below.
Three of these species are birds that do not nest in the Natomas Basin but forage in the Basin in winter or during migration: Aleutian Canada goose, white-faced ibis, and bank swallow. Based on 2001 land cover, the Greenbriar project (with the DEIR mitigation) would decrease the acreage of foraging habitat available for these species in the Natomas Basin by 1–3% and would preserve and enhance 0–2% of the foraging habitat in the Basin. Because the size of these populations is not limited by the availability of foraging habitat in winter, or during migration, and the Greenbriar project would not substantially alter the availability of such foraging habitat, the project’s effect on foraging habitat would be unlikely to alter the viability of these populations. The project would also increase the acreage of nesting habitat for white-faced ibis, and this could increase the likelihood of white-faced ibis establishing a nesting colony in the Natomas Basin; while not discounted, this effect was not considered likely.
The Greenbriar project would cause both adverse and beneficial effects on burrowing owl and loggerhead shrike populations in the Natomas Basin, but effects due to the project would be insufficient to alter the viability of these populations. Based on 2001 land cover, the project would preserve approximately 345 and 141 acres of shrike and owl habitat, respectively, and this beneficial effect would at least partially offset the project’s adverse effects on these species. Adverse effects would include a net loss of 141 acres of habitat for the shrike, and for both species a loss of occupied habitat, habitat fragmentation, and probably some increased mortality and habitat degradation adjacent to the Greenbriar site. However, the project’s effects would be small relative to the quantity of habitat that would remain in the Natomas Basin (for example, the project would eliminate 1% of shrike habitat), and the Natomas Basin represents only a small portion of the habitat for and population of these species in the Central Valley; thus, the project is unlikely to measurably alter the viability of the loggerhead shrike and burrowing owl populations using the Natomas Basin.
The project (with the DEIR mitigation) could cause a small adverse or beneficial effect on tricolored blackbird use of the Natomas Basin, but in either case this effect is unlikely to alter the viability of the tricolored blackbird population using the Natomas Basin. Based on 2001 land cover, the Greenbriar project would increase the quantity of nesting habitat in the Natomas Basin (by 201 acres or about 9%), but would decrease the quantity of foraging habitat (by 598 acres or about 3%). This loss of foraging habitat would be partially (but not fully) offset by the preservation and enhancement of 135 acres of foraging habitat. Although currently, nesting habitat is more limited than foraging habitat in the Natomas Basin, under the future condition much more nesting habitat will exist, and thus the additional nesting habitat that would be provided by the project may not affect the tricolored blackbird population more than the loss of foraging habitat that would also result. However, because the project would only cause a small beneficial or adverse effect on tricolored blackbird use of the Natomas Basin, and because the Natomas Basin accounts for only a small portion of the habitat for and population of tricolored blackbird in the Central Valley, the Greenbriar project is unlikely to alter the viability of the tricolored blackbird population using the Natomas Basin.
The project with the mitigation proposed in the DEIR would result in both adverse and beneficial effects on the Swainson’s hawk population nesting and foraging in the Natomas Basin, but these effects would be insufficient to alter the population’s viability. Adverse effects would include a reduction in the total acreage of foraging habitat under the future condition (by 222 acres or 2%), fragmentation, and possibly degradation of habitat near the Greenbriar site, and a reduction in habitat available to hawks nesting at reserves near the Greenbriar site.
Beneficial effects would include an overall increase in the acreage of high quality habitat, enhancing and preserving habitat within a mile of TNBC reserves, and possibly contributing to the connectivity of foraging habitat adjacent to proposed reserves and the mitigation site required by mitigation measure 6.13-2 of the DEIR.
Greenbriar Development Project EDAW
City of Sacramento vii Analysis of Effects on the Natomas Basin HCP Overall, the project would have a neutral effect. This interpretation is based on the USFWS interpretation of effects on Swainson’s hawk due to the NBHCP (USFWS 2003). The availability of foraging habitat during April– August (the nesting period) is considered to limit the abundance and reproductive success of Swainson’s hawk in the Natomas Basin (CH2M HILL 2003, USFWS 2003). Based on the methods used by CH2M HILL (2003) to evaluate availability of foraging habitat, the enhancement of habitat at the proposed reserves and mitigation sites would increase the availability of foraging habitat during these months. Using an alternative analysis developed by EDAW, this effects analysis estimated that during April–June the increase in foraging habitat values at the proposed reserve and mitigation sites would be about 6% greater than the habitat values lost by development at the Greenbriar site; during July–August, foraging values would not be fully offset, but foraging habitat values would be higher within the Natomas Basin as a whole at this time because of the harvesting of crops. Thus, based on these analyses, the project would not be expected to reduce the number of hawks nesting in the Natomas Basin or their reproductive success.
The project would cause both adverse and beneficial effects on the populations of giant garter snake and northwestern pond turtle that use canals, wetlands, and rice in the Natomas Basin; overall, the project would not adversely affect these populations. Beneficial effects would include preserving, creating, and enhancing habitat at the reserve sites, preserving and enhancing a 250-foot wide corridor along a portion of Lone Tree Canal, and contributing to the connectivity of habitat and existing TNBC reserves adjacent to or near the proposed reserves.
Adverse effects would include a reduction in the total acreage of habitat by 204 acres, and possibly degradation of habitat near the Greenbriar site and reduced connectivity along Lone Tree Canal as a result of increased human disturbance and predation (which would result from narrowing the corridor of land along Lone Tree Canal, and placing residential development adjacent to it). The DEIR mitigation would reduce these adverse effects and ensure that connectivity of giant garter snake habitat was conserved along Lone Tree Canal at the Greenbriar site.
For example, to minimize risks to connectivity due to human disturbance and predation, the DEIR mitigation includes requirements for fencing and barriers, and the creation of habitat along the canal.
The loss of habitat acreage would be offset by the increased habitat quality resulting from the preservation of habitat, and conversion of rice to marsh. The project (with the DEIR mitigation) also would conserve connectivity and habitat for giant garter snake along the affected section of Lone Tree Canal, which is an important waterway connecting the southern and central Natomas Basin, and proposed reserves would contribute to connectivity of habitats and reserves in the southern and central Basin.
Of the seven plant species covered by the NBHCP, the Greenbriar project would not affect the five vernal pool- associated species because these species are not known to occur in the vicinity of the Greenbriar or proposed reserve sites, nor is suitable habitat present at or near these sites. These plant species are: Boggs Lake hedge- hyssop, Sacramento Orcutt grass, slender Orcutt grass, Colusa grass and legenere. The other two covered plant species (delta tule pea and Sanford’s arrowhead) are not known to occur at the Greenbriar or the proposed reserve sites, but suitable habitat for these species does occur at or near some of these sites, which have not been surveyed for these species. Overall, the project would increase the acreage of suitable habitat for these species (i.e., marsh and canal habitats) in the Natomas Basin. Nonetheless, because these species are not known to occur in the Natomas Basin, the project probably would not alter the viability of any of their populations.
ES 3.2 EFFECTS ON THE CONSERVATION STRATEGY OF THE NBHCP The Greenbriar project (with the DEIR mitigation) would not reduce the effectiveness of the NBHCP’s conservation strategy. In Section IV.C.1 (pages IV 5-15), the NBHCP describes the basis of the key components of the NBHCP’s conservation strategy and how these components provide effective mitigation for 17,500 acres of urban development. These components are:
► basis for 0.5 to 1 mitigation ratio (Section IV.C.1.a), ► preparation of site specific management plans (Section IV.C.1.b), ► buffers within the reserve lands (Section IV.C.1.c),
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Analysis of Effects on the Natomas Basin HCP viii City of Sacramento ► connectivity (Section IV.C.1.d),
► foraging habitat (Section IV.C.1.e), and
► 2,500-acre/400-acre minimum habitat block size requirements (Section IV.C.1.f).
In describing the basis for the 0.5:1 mitigation ratio, the NBHCP states that the ratio mitigates the impacts of the incidental take authorized under the NBHCP because much of the land to be developed does not provide habitat or provides only marginal habitat, and because the TNBC-managed reserves will provide habitat of higher quality than the eliminated habitat. Because the Greenbriar project would not alter the habitat value of land authorized for development under the NBHCP, and would not adversely affect the habitat value of TNBC reserves established under the NBHCP, the project would not affect the basis for the 0.5:1 mitigation ratio of the NBHCP. Although the project would result in the conversion of agricultural land and open space to urban development on an additional 546 acres of land in addition to the 17,500 acres of permitted development under the NBHCP, with the proposed mitigation, this conversion to urban development would result in a minimal change to the conditions in which the NBHCP conversation strategy is being implemented.
The Greenbriar site is not adjacent to existing TNBC reserves, and thus would not alter the effectiveness of the buffers within these reserve lands. Also, because under the future condition of the Natomas Basin resulting from the NBHCP, the Greenbriar site would already be bordered by urban development, highways or major roads on all sides, development of the Greenbriar site could cause only very limited effects on the effectiveness of buffers within future reserves, even if reserves were established on adjacent land to the north or southwest (i.e., adjacent land that would not be developed under the future condition of the Natomas Basin).
The development and reserves resulting from the Greenbriar project would, however, need to be considered in the development of site-specific management plans for existing and future reserves in their vicinity. Although the loss of raptor habitat at the Greenbriar site would be mitigated, there would still be less foraging habitat in the vicinity of some sites as a result of the project, which could alter site-specific plans. Also, the proposed reserves would provide additional options for management and future acquisitions that could alter the management plans of nearby TNBC reserves.
Overall, the project with the DEIR mitigations would not reduce connectivity of reserves or habitats within the Natomas Basin. The proposed reserve and mitigation sites would probably improve connectivity of habitats and TNBC reserves, and potential adverse effects on Lone Tree Canal would be minimized by measures included in the project design and additional mitigation measures in the DEIR. A comprehensive set of measures would be implemented to both reduce the project’s effects on and to enhance the habitat in a 250-foot wide corridor along the Lone Tree Canal, which would provide garter snake habitat connectivity. These measures would prevent the project from reducing the connectivity of canal habitats and TNBC reserves, and also would prevent the project from subdividing the Basin’s giant garter snake population into two smaller, and thus less viable, populations.
With the DEIR mitigation, the project would not reduce the availability of foraging resources for the Swainson’s hawk in the Natomas Basin, and thus not affect reproduction or survival. Based on 2001 land cover, the Greenbriar project, however, would result in a net reduction of 253 acres of upland land cover providing habitat for covered species, it would enhance or create, and preserve, at least 135 acres of upland land cover types (plus 60 acres of upland components of created marshes). As a result, the upland habitats that would result from the project would provide foraging resources during the months of April–August (when Swainson’s hawks are nesting in the Basin) comparable to the habitats that would be eliminated by the project. Based on the method CH2M HILL (2003) used to analyze effects of the NBHCP, the acreage of available foraging habitat would be increased by the project; based on the additional analysis conducted by EDAW for this effects analysis, the increase of habitat values resulting from enhancement would be greater than values lost at the Greenbriar site during April–June but not during July–August. Although the loss of values would not be fully offset during July– August, foraging resources increase in the Natomas Basin during those months from the harvesting crops, and therefore, Swainson’s hawk is unlikely to be affected. (Both the mitigation and eliminated habitat would be within a mile of nesting habitat that is currently occupied.) By maintaining foraging resources during the critical April–
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City of Sacramento ix Analysis of Effects on the Natomas Basin HCP June period, the Greenbriar project would not compromise the NBHCP Operating Conservation Program, and thus actions such as those listed on pages IV-13 and IV-14 of the NBHCP would not be necessary.
Overall, the project would avoid, minimize and mitigate adverse effects of development by establishing large blocks of preserved habitat. It would enhance and preserve 296 acres of additional habitat adjacent to or near existing TNBC reserves and the DEIR mitigation would increase this benefit by requiring the preservation of at least an additional 49 acres of land. The project would adversely affect the preservation of large blocks of habitat by developing existing habitat at the Greenbriar site. Under the future condition of the Natomas Basin, this land would be surrounded by major roads and urban development, and the Greenbriar project includes design measures to preserve the most ecologically important portion of the site, the corridor of land along Lone Tree Canal.
ES 3.3 EFFECTS ON ATTAINMENT OF NBHCP GOALS AND OBJECTIVES For many of the same reasons that viability of populations and the effectiveness of the NBHCP’s conservation strategy would not be reduced, the Greenbriar project would not reduce the likelihood of attaining the goals and objectives of the NBHCP. Below, the overall effect resulting from the project (with the DEIR mitigations) is summarized for each goal or objective that could be affected.
Overall Goal 1. Establish and manage in perpetuity a biologically sound and interconnected habitat reserve system that mitigates impacts on Covered Species resulting from Covered Activities and provides habitat for existing, and new viable populations of Covered Species. (NBHCP, p. I-15) The project (with its mitigation) would have an overall beneficial effect on the establishment and management of reserves for the NBHCP. Because the acreage of land in the Natomas Basin that is potentially available and suitable for preservation substantially exceeds the 8,750 acres that will be preserved by the NBHCP, the project would not preclude the preservation of sufficient land to attain the NBHCP’s goals and objectives. It would provide reserve lands adjacent to or near existing reserves, increasing the connectivity of habitats and the resources available to covered species using reserves established by the NBHCP; in addition, it would conserve a portion of an important corridor of canal habitat along Lone Tree Canal. The project also would increase opportunities to establish new reserves, particularly to create larger reserves by preserving additional land adjacent to the project’s proposed and existing TNBC reserves.
Although the project would cause a net reduction in the acreage of upland and wetland habitats, the preservation and enhancement of habitat by the project would adequately mitigate for its effects on upland and wetland habitats of covered species. Based on 2001 land cover mapping, the Greenbriar project would eliminate 388 acres of rice and 16 acres of canal habitats, but would increase the acreage of marsh by 201 acres, creating a net loss of 204 acres of these wetland land cover types and of the habitats they provide. An acre of marsh, however, provides a greater quantity and variety of habitat than does an acre of rice for several reasons. These reasons include:
► Giant garter snakes primarily use the margins of rice fields, whereas they use the full extent of managed marshes. These marshes are designed to provide open water, foraging habitat, dense cover, basking sites, and refugia in close proximity throughout the marsh. (For example, an acre of managed marsh provides several times the edge habitat than does a rice field.)
► Marshes provide habitat throughout the active period of the snake. Rice fields do not provide habitat during early and mid-spring, and are typically drained before the end of the snake’s active period. Thus, for a portion of their active period, giant garter snakes must rely entirely on non-rice habitats. In the Natomas Basin, these habitats are canals and managed marsh. In contrast, managed marshes provide habitat year-round. ► Rice is fallowed periodically, and thus does not provide habitat in all years; in contrast, a managed marsh does provide habitat in all years.
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Analysis of Effects on the Natomas Basin HCP x City of Sacramento Thus, the additional habitat values provided by the created marsh offsets the habitat values lost in the rice and canal land cover types. In addition, the project would preserve, and manage for its habitat values, the 201 acres of created marsh (i.e., about 1 acre for each acre lost), ensuring the long-term persistence of this habitat. Similarly, based on 2001 land cover, the Greenbriar project would cause a net reduction of 253 acres of upland land cover providing habitat for covered species, but would enhance and preserve 135 acres of upland habitats (plus 60 acres of upland components in created marshes for a total of 195 acres of upland habitat preserved). For most covered species associated with upland habitats, the additional habitat values resulting from this enhancement and preservation would offset the project’s reduction of the acreage of upland habitats in the Natomas Basin. For example, during the months of April–August, when Swainson’s hawks are nesting in the Basin, the enhancement of upland habitats that would result from the project would provide foraging resources comparable to the habitats that would be eliminated by the project.
As previously described, the potential effects (both adverse and beneficial) that would result from implementing the proposed project (including the DEIR mitigation) would be unlikely to alter the population viability of any of the covered species.
Overall Goal 3. Preserve open space and habitat that may also benefit local, non-listed and transitory wildlife species not identified within the NBHCP. (NBHCP, page I-16) As described under Overall Goal 1 above, the project would have an overall beneficial effect on the TNBC reserve system. Furthermore, the project (with DEIR mitigation) would slightly increase the ratio of habitat preserved to habitat developed in the Natomas Basin by setting aside land at a ratio (0.6:1) that exceeds the 0.5:1 ratio required for development authorized by the NBHCP, and would include more extensive creation, enhancement, and management of habitat. For these reasons, the project (with the DEIR mitigation) would have an overall beneficial effect on the attainment of this goal.
Overall Goal 4. Ensure that direct impacts of Authorized Development upon Covered Species are avoided or minimized to the maximum extent practicable. (NBHCP, page I-16) With the DEIR mitigation, the project would not adversely affect attainment of this goal because it would implement a comprehensive set of measures to avoid and minimize effects on covered species to the maximum extent practicable. The potential direct impacts are comparable to the potential direct impacts of the development authorized by the NBHCP. Thus, the Greenbriar project with the DEIR mitigation would include all of the applicable avoidance and minimization measures included in the NBHCP to avoid and minimize construction- related effects, and several more stringent minimization measures. The project also would include a set of measures to avoid and minimize effects on the Lone Tree Canal corridor. The Greenbriar project also would not alter the effectiveness of any NBHCP conservation measures for avoiding and minimizing the effects of development authorized by the NBHCP.
Overall Objective 1. Minimize conflicts between wildlife and human activities, including conflicts resulting from airplane traffic, roads and automobile traffic, predation by domestic pets, and harassment by people. (NBHCP, page I-16).
With the DEIR mitigation, the project would not adversely affect attainment of this objective because it would implement a comprehensive set of measures that would minimize human-wildlife conflicts. These measures include all of the applicable measures that were included in the NBHCP to avoid and minimize construction- related effects and to reduce human-wildlife conflicts, plus additional measures (e.g., fencing and barriers) to reduce human-wildlife conflicts along Lone Tree Canal. The Greenbriar project also would not alter the effectiveness of any NBHCP conservation measures for minimizing human-wildlife conflicts resulting from development authorized by the NBHCP.
Overall Objective 3. Ensure connectivity between TNBC reserves to minimize habitat fragmentation and species isolation. Connections between reserves will generally take the form of common property boundaries between
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City of Sacramento xi Analysis of Effects on the Natomas Basin HCP reserves, waterways (primarily irrigation and drainage channels) passing between reserves, and/or an interlinking network of water supply channels or canals. (NBHCP, page I-16) The Greenbriar project would cause beneficial and adverse effects on the attainment of this objective through most of these mechanisms; its overall effect, however, would not be adverse. The main beneficial effects would be increased connectivity of habitats and TNBC reserves due to preservation, creation and enhancement of habitat at the project’s proposed reserves, two of which are adjacent to or near (i.e., within a half mile of) existing TNBC reserves. Adverse effects would include reducing the foraging habitat within a mile of a TNBC reserve, fragmenting and reducing the connectivity of upland habitats adjacent to the Greenbriar site, and possibly reducing the connectivity of wetland habitats and TNBC reserves because of effects on Lone Tree Canal (despite preserving a corridor along the canal). The DEIR mitigation would reduce these adverse effects by incorporating additional measures to ensure that connectivity along Lone Tree Canal is sustained, and to preserve and enhance foraging habitat within a mile of existing TNBC reserve(s). (The connectivity of upland habitats, however, would still be reduced at the Greenbriar site.) In the absence of an adverse effect on connectivity along Lone Tree Canal, the project would cause only small effects on the attainment of this objective, and most of these effects would be beneficial.
Wetland Species/Habitat Goal/Objective 1. Acquire, enhance and create a mosaic of wetland habitats with adjacent uplands and connecting corridors to provide breeding, wintering, foraging, and cover areas for wetland species in the Plan Area. (NBHCP, page I-17)
For wetland land cover (i.e., rice, canal, and ponds and seasonally wet areas), the net reduction in acreage resulting from the development of the Greenbriar site would be offset by creating and managing marsh at the project’s proposed reserves. Based on 2001 land cover mapping, the Greenbriar project would eliminate 388 acres of rice and 16 acres of canal habitats, but would increase the acreage of marsh by 201 acres, creating a net loss of 204 acres of these wetland land cover types and of the habitats they provide. An acre of marsh, however, provides a greater quantity and variety of habitat values than does an acre of rice, and thus the additional habitat provided by the created marsh offsets the habitat lost in the rice and canal land cover types. In addition, the project would preserve, and manage for its habitat values, the 201 acres of created marsh (i.e., about 1 acre for each acre lost), ensuring the long-term persistence of this habitat.
The project would not have an overall adverse effect, and might have a beneficial effect on, connectivity of wetland habitats. This overall effect on connectivity of wetland habitats is described under Overall Objective 1 above.
Wetland Species/Habitat Goal/Objective 2. Provide habitat to maintain, attract and sustain viable populations of the Covered Species. The habitat areas should be configured to encompass natural species migration areas, minimize species isolation, and prevent future habitat fragmentation. (NBHCP, page I-17) The project would enhance and preserve habitat to offset its adverse effects and that would sustain populations of the covered species, and would not alter the population viability of any of the covered species. The habitat enhanced and preserved by the project and the project’s effects on the TNBC reserve system are described under Overall Goal 1 above. The project’s effect on the viability of each covered species is described under Effects on Covered Species above.
Upland Species/Habitat Goal/Objective 1. Acquire, enhance and create a mosaic of upland habitat types for breeding, foraging, and cover for species dependent on upland habitats. (NBHCP, page I-17) Overall, the project would not adversely and could beneficially affect this goal/objective. Because the acreage of upland habitat in the Natomas Basin that is potentially available and suitable for preservation is substantially more than the acreage of upland habitat that would be preserved and enhanced by the NBHCP, and the project would affect only a small percentage of this land, the project would not preclude the preservation of sufficient land to
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Analysis of Effects on the Natomas Basin HCP xii City of Sacramento attain the NBHCP’s goals and objectives. The project would, however, increase opportunities to establish new and/or larger reserves, which would aid the attainment of this goal/objective.
Upland Species/Habitat Goal/Objective 2. Ensure reserve land connectivity with travel corridors for upland- dependent species. The habitat areas should encompass grasslands, agricultural croplands, riparian habitats, and shelter and nesting habitat areas (fence rows, clusters of shrubs and small trees), as well as wetland areas to provide a year-round source of water for upland species. The upland areas should be configured to enhance natural species migration, minimize species isolation, and prevent future habitat fragmentation. (NBHCP, page I- 17)
A moderate level of uncertainty exists regarding the overall effect of the Greenbriar project on this goal/objective.
The proposed changes at the Greenbriar site would have an uncertain effect on the movement and dispersal of upland species; also there is uncertainty regarding the project’s contributions to connectivity elsewhere in the Basin because the location of the mitigation site that would account for much of upland habitat preserved has not been determined. However, because the project would cause adverse and beneficial effects that are similar in nature and magnitude, and would affect only a small portion of the Basin’s land area, the project would have only a small overall effect on the attainment of this goal/objective, whether it was beneficial or adverse.
ES.4 SUMMARY
In summary, the Greenbriar project (with the DEIR mitigation) would not reduce the viability of populations of covered species using the Natomas Basin and would not reduce the effectiveness of the conservation strategy of the NBHCP. It also would have only small effects on the likelihood of attaining any of the goals and objectives of the NBHCP, and for most of these goals and objectives the overall effect would be neutral or beneficial.
Greenbriar Development Project EDAW
City of Sacramento 1-1 Analysis of Effects on the Natomas Basin HCP 1 INTRODUCTION
This section presents the scope of the effects analysis, an overview of the proposed Greenbriar project, and the intended uses of this document. This section also summarizes the organization of the Effects Analysis.
1.1 INTRODUCTION
This analysis of effects of the Greenbriar project on the Natomas Basin Habitat Conservation plan (effects analysis) evaluates the effects of the Greenbriar project on each species covered by the Natomas Basin Habitat Conservation Plan (NBHCP), on the conservation strategy of the NBHCP, and on attainment of the NBHCP’s goals and objectives. This project would include development at the Greenbriar site, which is located within the boundaries of the NBHCP plan area, but is not within an area permitted for development. The project also includes establishment of onsite and offsite reserves. The project could affect the population viability of species covered by the NBHCP, the conservation strategy of the NBHCP, or the attainment of the NBHCP’s goals and objectives. The purpose of this evaluation is to document the potential effects of the Greenbriar project and evaluate its overall effect on the viability of populations of species covered by the NBHCP and on attainment of the goals and objectives of the NBHCP. Effects on the Metro Air Park Habitat Conservation Plan (MAP HCP) also were considered. However, the MAP HCP was designed to support and follow the regional conservation strategy of the NBHCP; its covered species are a subset of those covered by the NBHCP, and its biological goals and objectives largely represent a subset of the NBHCP’s goals and objectives. (In fact, the MAP HCP has been superseded by the 2003 NBHCP.) Thus, the results of this effects analysis also document the project’s potential effects on the MAP HCP’s covered species and biological goals and objectives. Potential conflicts with and relationships to specific measures of the MAP HCP are also included in this evaluation.
The NBHCP was developed to satisfy the requirements of the Endangered Species Act for a permit for the incidental take of threatened and endangered species. It is intended to minimize and mitigate for the loss of habitat and the incidental take of covered species that could result from urban development and management of reserves in the Natomas Basin. The NBHCP authorizes 17,500 acres of development in the MAP, City of Sacramento, and Sutter County permit areas, and outside of these areas it preserves 8,750 acres in a reserve system surrounded by agricultural lands (Exhibit 1). The reserve system will consist of 4,375 acres of rice, 2,187 acres of created marsh, and 2,187 acres of upland habitat. In this reserve system, land will be managed to enhance its habitat values. The future condition of the Natomas Basin resulting from the NBHCP would provide fewer acres of habitat for covered species than existed in 2001. The U.S. Fish and Wildlife Service (USFWS) considers the reserve system with high quality habitat created by the NBHCP to adequately mitigate and offset the effects of this habitat loss because most of the lost habitat would be of lower quality (USFWS 2003). Consequently, most of the NBHCP’s goals and objectives are related to creating a reserve system that provides high quality habitats and is likely to sustain populations of the covered species in the Natomas Basin for the foreseeable future. The NBHCP also includes numerous avoidance, minimization, and mitigation measures to reduce the effects of development on covered species and to ensure the creation and effective operation of the reserve system.
1.2 OVERVIEW OF GREENBRIAR PROJECT
The Greenbriar project would develop the 577-acre Greenbriar site located northwest of the intersection of State Route 99 and Interstate 5 in Sacramento County (Exhibit 2). This site is bordered by agricultural land uses to the north and south, new residential development to the east, and the recently approved Metro Air Park development to the west. As currently proposed, the project would create a residential development with commercial and retail centers, an elementary school, neighborhood parks and a water feature (approximately 39 acres in size). A new east-west roadway, Meister Way, would be constructed through the center of the site. Along this roadway, a new light rail station is proposed to be eventually constructed by Sacramento Regional Transit near the center of the site that would connect the Greenbriar site to the Sacramento International Airport development to the west and to
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Analysis of Effects on the Natomas Basin HCP 1-2 City of Sacramento
Source: CH2M HILL, EDAW 2005
Location of Greenbriar Project in the Natomas Basin Exhibit 1
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City of Sacramento 1-3 Analysis of Effects on the Natomas Basin HCP
Source: CH2M HILL, Ellen Berryman, Sacramento County 2002
Project Boundary and Conservation Easement Locations at the Greenbriar Site Exhibit 2
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Analysis of Effects on the Natomas Basin HCP 1-4 City of Sacramento the North Natomas Community to the east across Highway 99 via a new proposed overpass over Highway 99.
This development is adjacent to, but outside of, the areas of development permitted by the NBHCP.
Along with this development, the project would preserve, enhance, and create habitat in a 250-foot wide corridor along the site’s western edge (occupying approximately 31 acres) and would preserve, enhance, and create habitats off-site at two proposed reserves: the Natomas 130 (30.2 acres, primarily of alfalfa and created marsh with smaller acreages of canal, riparian, and tree grove) and Spangler (235.4 acres, primarily of alfalfa and created marsh with a smaller acreage of canal) reserves.
Preserved lands would become part of reserve system operated by TNBC, or if necessary would be managed by another nonprofit entity. For each reserve, TNBC develops a site-specific management plan, and management activities include habitat management, monitoring, invasive plant control, domestic/feral animal control, and restricting public access and patrolling reserves to enforce restrictions. As part of its management, TNBC also implements a set of measures to avoid and/or minimize take of covered species. These measures are described on pages IV-29 through IV-38 of the NBHCP.
The fee title and an endowment would be provided to TNBC (or if necessary another nonprofit entity) by the project proponent. The endowment would provide for the restoration/enhancement, operation, maintenance, monitoring, and administration of the reserves. For the reserves proposed by the Greenbriar project, a larger endowment fee than that required for NBHCP mitigation may be necessary to provide for the required management. Additional details regarding Greenbriar’s funding of these reserves will be developed through the HCP amendment or HCP process together with the development of reserve management plans. The reserve management plans will include details regarding effectiveness monitoring, adaptive management, and a schedule for acquisition of reserve uplands and implementation of all mitigation measures required through the Section 10(a)(1)(B) and Section 2081 permit processes. (For the proposed reserve along Lone Tree Canal, the management plan will include a legal agreement with the Natomas Mutual Water Company regarding vegetation management.) These reserve management plans will form the basis for calculating Greenbriar’s endowment fee in consultation with the wildlife agencies.
In addition to the proposed reserves and measures incorporated as part of the proposed Greenbriar project, the City of Sacramento, through the CEQA process, has proposed mitigation measures for the project to reduce further the project’s adverse effects. (Throughout this document, “mitigation” refers to these measures proposed by the City of Sacramento in the DEIR, unless otherwise noted as measures incorporated into the Greenbriar project’s design.) These DEIR mitigation measures include the preservation of at least an additional 49 acres of land managed to provide high quality Swainson’s hawk foraging habitat. This preserved land also would become part of TNBC reserve system. The location of this mitigation land has not yet been determined.
The Greenbriar site is outside of the area permitted for development; thus, the habitat loss, preservation and enhancement resulting from the project is in addition to that permitted by the NBHCP. Consequently, the project would alter the future condition of the Natomas Basin.
1.3 USE OF THIS DOCUMENT
The Greenbriar EIR and Effects Analysis operate in tandem to evaluate the effects of implementation of the Greenbriar project on biological resources. The EIR satisfies the requirements of CEQA partly by considering these effects in light of the NBHCP, IA, and ITP requirements as analyzed in depth in the Effects Analysis (DEIR, Appendix P). The Greenbriar Project is located outside of the 17,500 acre permit area of the NBHCP. The NBHCP, Implementation Agreement, Biological Opinion and ITPs provide that because the NBHCP’s Operating Conservation Plan is based upon the City limiting total development to 8,050 acres within the City’s Permit Area, approval by the City of future urban development beyond the 8,050 acres or outside of its Permit Area would “constitute a significant departure from the NBHCP’s OCP” and would trigger reevaluation of the NBHCP, a new effects analysis, potential amendments and/or revisions to the NBHCP and ITPs, a separate conservation strategy
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City of Sacramento 1-5 Analysis of Effects on the Natomas Basin HCP and the need to obtain a new ITP by the Permittee for that additional development, and/or possible suspension or revocation of the City’s ITP in the event the City were to violate such limitations without having completed the required reevaluation, and amendments or revisions if necessary, or having obtained a new permit. (See e.g., Implementation Agreement for the NBHCP, Section 3.1.1[a].) As part of this process, Greenbriar intends to file an application for a project-specific HCP.
This EIR evaluates the effects of the Greenbriar project in consideration of the NBHCP, IA and ITP requirements and is based upon an Effects Analysis prepared by the City’s EIR consultant with biological resource information provided by Greenbriar’s biologists. The purpose of this effects analysis is to support the analysis contained in the EIR and to provide the foundation for the preparation of an amendment to the NBHCP or a new HCP for the addition of the Greenbriar project to the City’s permit area.
When the amendment to the NBHCP or new HCP process is initiated with USFWS and CDFG, the Effects Analysis will be reviewed by the USFWS and CDFG through the Section 10(a)(1)(B) and Section 2081 permit processes to assure the Greenbriar project’s consistency with federal and state endangered species act requirements and to guide the wildlife agencies in their determinations as to the project’s effects on the effectiveness of the NBHCP. Following development of an amendment to the NBHCP or new HCP, the City and/or the Greenbriar project applicant will be required to obtain amended or new ITPs from USFWS and CDFG authorizing incidental take of state and federally listed threatened and endangered species.
If LAFCo approves the proposed annexation of the Greenbriar Project to the City, then the City and/or Greenbriar project applicant will be required to initiate a new HCP or NBHCP amendment process with the wildlife agencies prior to final map approval. USFWS approval of the HCP/NBHCP amendment and issuance of the ITP/ITP amendment will be subject to review under NEPA. The Greenbrier EIR would provide a basis for consideration of environmental impacts under NEPA, and it is intended to provide the environmental information for CDFG action under CEQA. However, CDFG consideration of the HCP/HCP amendment and ITP/ITP amendment could result in subsequent environmental review under CEQA, if CDFG determines, on the basis of substantial evidence in light of the whole record, that there are substantial changes in the project or circumstances in which the project is undertaken, or new information indicates that new or substantially more severe significant environmental effects would occur than were covered in the Greenbriar EIR. Although incidental take would not occur until grading of the site occurs, issuance of the ITPs/amendments will be required prior to final map approval by the City of Sacramento to ensure that any adjustments to the subdivision map approvals (e.g., changes in site design) resulting from the HCP/ITP process occur prior to recordation of a final map.
1.4 ORGANIZATION
This report presents the results of an analysis of the effects of the Greenbriar project (with the DEIR mitigation) on the future condition of the Natomas Basin, and how those changes would affect species covered by the NBHCP and attainment of the NBHCP’s goals and objectives.
The Effects Analysis is organized in the following way:
► Section 1, Introduction
► Section 2, Evaluation Approach
► Section 3, Greenbriar Project’s Alteration of Population and Habitat Attributes ► Section 4, Potential Effects of the Greenbriar Project on Covered Species ► Section 5, Potential Effects on the Conservation Strategy of the NBHCP ► Section 6, Potential Effects of the Greenbriar Project on NBHCP Goals and Objectives
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Analysis of Effects on the Natomas Basin HCP 1-6 City of Sacramento ► Section 7, Cumulative Effects
► Appendix A, Assessment of Avoidance and Minimization of Construction-related Effects and Human- Wildlife Conflicts
► Appendix B, Change in Natomas Basin Land Cover in 2001–2004
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City of Sacramento 2-1 Analysis of Effects on the Natomas Basin HCP 2 EVALUATION APPROACH
2.1 OVERVIEW
The Greenbriar project could affect covered species, effectiveness of the NBHCP conservation strategy, effectiveness of specific conservation measures, attainment of NBHCP goals and objectives, or cumulative effects by altering any of several population or habitat attributes. These attributes include:
► Construction-related effects on survival and reproduction, ► Zones with human-wildlife conflicts (i.e., areas adjacent to developed lands and roads), ► Acreage of habitat in Natomas Basin,
► Quality of habitat in the Natomas Basin,
► Connectivity of habitat in Natomas Basin,
► Connectivity of existing TNBC reserves,
► Habitat value of existing TNBC reserves,
► Water availability at TNBC reserves, and
► Opportunities to establish additional TNBC reserves.
For each of these attributes, alterations resulting from the Greenbriar project were analyzed. The findings of this effects analysis of the effects on covered species, effectiveness of the NBHCP conservation strategy, effectiveness of specific conservation measures, and NBHCP goals and objectives was based on the results of the analyses of the above attributes. The methodologies and the bases for the interpretations of effects on covered species and NBHCP goals and objectives are described below. In addition, this analysis of effects on covered species was also based on available information on the distribution of these species in the Natomas Basin and on their ecology.
Analyses of cumulative effects also were based on the results of these analyses together with additional analyses of land cover, and the compilation and review of projects proposed in the Natomas Basin.
2.2 DESCRIPTION OF GREENBRIAR PROJECT
The analysis of the effects of the Greenbriar project is based on a description of the project (including the mitigation measures proposed as part of the project design) that was compiled from multiple sources. The primary source was the Greenbriar Draft Environmental Impact Report (DEIR) (EDAW 2005). Additional information was derived from the draft conceptual mitigation plan for the project (Wildlands, Inc. 2005), Greenbriar Draft Biological Assessment (BA) (Berryman Ecological 2005), and personal communications with project consultants.
The draft conceptual mitigation plan describes the proposed Natomas 130 and Spangler reserves, and the proposed on-site reserve along Lone Tree Canal, and the proposed restoration of these areas to provide upland and wetland habitats. This conceptual mitigation plan also evaluated whether the proposed reserve sites met the TNBC’s typical conditions for mitigation-land dedication. The draft BA includes proposed avoidance and minimization measures, and a description of the proposed preservation, restoration, and future management of habitat along Lone Tree Canal.
After the conceptual mitigation plan and draft BA were produced, several changes were made to the proposed habitat creation and enhancement at the Natomas 130 and Spangler sites. First, the proposed acreage of restored habitats was changed to 204.2 acres of managed marsh and associated canals (14.2 acres at Natomas 130 created from upland non-rice cropland and 190 acres at Spangler created from rice) and 59.6 acres of upland in alfalfa (14.2 acres at Natomas 130 and 45.4 acres at Spangler). The managed marsh would have 30% upland components. A revised conceptual mitigation plan that reflects these changes is under development. This effects analysis also assumed that development of an HCP for this project would result in mitigation providing habitat values comparable or greater than the proposed acreage of marsh and alfalfa evaluated in this effects analysis.
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP 2-2 City of Sacramento As indicated by the draft conceptual mitigation plan, and as explicitly required by the DEIR mitigation, the proposed reserves would be dedicated to TNBC, or another entity if necessary, with an endowment sufficient to pay for required restoration and management in perpetuity. The management of these reserves would be as described in sections VI-D, V-B, VI-E, VI-F, and VI-G of the NBHCP (Conservation Plan – Reserve/Management/Site Specific Management Plans; Take Avoidance, Minimization, and Mitigation; and Plan Implementation-Monitoring of the NBHCP, Adaptive Management, Annual Report, respectively) or that comparable management would be developed in consultation with USFWS and incorporated into an HCP for the project. As described in sections VI-D, V-B, VIE, VI-F, and VI-G of the NBHCP, this management would include:
► Development of a site-specific management plan;
► Implementation of measures to reduce take of covered species as a result of restoration and reserve management;
► Implementation of the NBHCP’s conservation strategies for covered species on the reserves; ► Management activities that include invasive plant control, domestic/feral animal control, and restricting public access and patrolling reserves to enforce restrictions; ► Compliance and biological effectiveness monitoring; and ► An annual reporting and review meeting to cover progress toward meeting goals, implementation, monitoring, and adaptive management measures.
The dedication of the proposed reserves and their endowments would occur prior to entitlement of the project, and restoration would be initiated within one year of their dedication. Because of their specific management requirements (e.g., having uplands planted in alfalfa), greater proportion of managed marsh, and the potentially high maintenance costs for the small reserve proposed along Lone Tree Canal, this endowment may be greater per acre than the endowment for NBHCP mitigation lands.
Furthermore, in the DEIR, mitigation includes preservation and enhancement of Swainson’s hawk foraging habitat, multiple measures to reduce effects on giant garter snake habitat and the snake’s use of Lone Tree Canal as a movement corridor, and development and approval of a Habitat Conservation Plan (HCP) for compliance with the federal Endangered Species Act.
The DEIR mitigation for Swainson’s hawk foraging habitat (mitigation measure 6.13-2) requires the preservation of an area of habitat that provides habitat values to the species comparable to the habitat eliminated at the Greenbriar site. This DEIR mitigation measure would require preservation of at least an additional 49 acres of land to be enhanced and managed to provide high quality Swainson’s hawk foraging habitat. The actual acreage of this mitigation will be determined during development of an HCP for the project (as described in the DEIR), and will depend on the site attributes and future management that determine the level of habitat enhancement (as described in Section 2.3.4 Quality of Habitat in the Natomas Basin).
The DEIR mitigation for giant garter snake includes measures to reduce the project’s effects on snakes use of Lone Tree Canal as a movement corridor. These measures include:
a. To ensure that the project does not diminish habitat connectivity for giant garter snake between the southwest and northwest zones identified in the NBHCP, approximately 30.6 acres along Lone Tree Canal shall be protected and managed as giant garter snake habitat. This on-site habitat preservation shall protect an approximately 250-foot wide corridor of giant garter snake habitat that includes the canal and approximately 200 feet of adjacent uplands. Uplands within the linear open space/buffer area shall be managed as perennial grassland as described below. Additional aquatic habitat for giant garter snake shall be created along the east
Greenbriar Development Project EDAW
City of Sacramento 2-3 Analysis of Effects on the Natomas Basin HCP bank of Lone Tree Canal by construction and maintenance of a 2.7 acre tule bench. The habitat shall be managed in perpetuity as high-quality habitat for giant garter snake. Compliance and biological effectiveness monitoring shall be performed and annual monitoring reports prepared within six months of completion of monitoring for any given year. This monitoring, reporting, and adaptive management shall be performed as described in Section IV of the NBHCP.
b. To ensure that the project does not diminish gian t garter snake movement along Lone Tree Canal, all new road crossings of Lone Tree Canal shall be designed to minimize obstacles to giant garter snake movement.
The use of culverts under new road crossings on Lone Tree Canal shall be prohibited unless it can be demonstrated that the culverts will not diminish the potential for giant garter snake movement through the section of Lone Tree Canal protected by the setback fence and conservation easement. . c. Upland giant garter snake habitat within the Lone Tree Canal linear open space/buffer area shall be created and managed to provide cover, basking areas, and refugia during the winter dormant period. Hibernaculae would be constructed at regular intervals by embedding concrete or coarse rock in the bank or in a berm along the Lone Tree Canal corridor to provide additional winter refugia. Upland habitat with the linear open space/buffer areas shall be converted to native perennial grassland and managed, in perpetuity, as perennial grassland habitat.
d. Aquatic habitat shall be maintain ed throughout the giant garter snake active season in Lone Tree Canal, in perpetuity. This is the legal responsibility and obligation of Metro Air Park property owners (MAP). The MAP HCP includes provisions for maintaining water in the canal such that the basic habitat requirements of the giant garter snake are met. The MAP HCP also provides a road map, through “Changed Circumstances”, to address procedures to follow if water is not being maintained in the canal to meet these requirements. As described in the MAP HCP, the MAP is legally obligated to assure these requirements are met, and financial and procedural mechanisms are included in the MAP HCP to enforce this. It is, therefore, assumed that MAP will provide water to Lone Tree Canal, as required by the MAP HCP and ITP, in perpetuity. It is also assumed that USFWS will use all reasonable means available to it, to enforce this MAP HCP requirement. If water is not provided to Lone Tree Canal by the MAP to meet the habitat requirements of giant garter snake, as required by the MAP HCP, and USFWS exhausts its enforcement responsibilities, the project applicant shall assume the responsibility of providing suitable giant garter snake aquatic habitat throughout the section of Lone Tree Canal protected by the fence and conservation easement. However, as stated herein, the project applicant shall only assume this responsibility if it has been sufficiently demonstrated to the City that USFWS has exhausted all reasonable means to compel MAP to comply with the relevant conditions of the MAP ITP.
Specific requirements related to ensuring suitable aquatic habitat in Lone Tree Canal is present, in perpetuity, throughout the giant garter snake active season shall be developed through consultation with DFG and USFWS, and included in the new or amended HCP for Greenbriar, and may include mechanisms, such as installation of a well, to assure water is provided in the canal to meet habitat requirements. e. A barrier shall be installed between the giant ga rter snake habitat linear open space/buffer area and the adjacent Greenbriar development to ensure that giant garter snakes do not enter the development area, and to prohibit humans and pets from entering the giant garter snake habitat. The design of this barrier shall be subject to USFWS and CDFG review and approval. The entire length of the barrier, which shall be bordered by yards rather than roadways, shall be maintained on the preserve side by a nonprofit land trust to ensure that vegetation or debris does not accumulate near the barrier and provide opportunities for wildlife and pets to climb over the barrier. On the development side, Covenants, Codes and Restrictions (CCRs) shall prohibit accumulation of vegetation or debris adjacent to the barrier. Chain link fencing shall be placed at both ends of the corridor, with locked gates permitting entry only by RD 1000 and NMWD for channel maintenance, and by the preserve manager for habitat monitoring and maintenance purposes.
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP 2-4 City of Sacramento f. Specific requirements associated with the barrier sh all be developed through consultation with USFWS and DFG, and may include the following and/or other specifications that DFG and USFWS consider to be equally or more effective:
► Adequate height and below-ground depth to prevent snakes or burrowing mammals from providing a through-route for snakes by establishing burrows from one side to the other crossing; ► Constructed using extruded concrete or block construction extending a minimum of 36-inches above ground level;
► Maintenance to repair the barrier and to prevent the establishment of vegetation or collection of debris that could provide snakes with a climbing surface allowing them to breech the barrier; ► A cap or lip extending at least two-inches beyond the barrier’s vertical edge to prevent snakes from gaining access along the barrier’s top edge; and
► Signage to discourage humans and their pets from entering the area. g. The Lone Tree Canal linear open space/buffer area sha ll be protected in perpetuity under a conservation easement and managed to sustain the value of this area for giant garter snake habitat connectivity. Compliance and biological effectiveness monitoring shall be performed and annual monitoring reports prepared. This monitoring, reporting, and adaptive management shall be performed as described in Section IV of the NBHCP or following procedures developed in formal consultation with USFWS and DFG and contained in an ESA Incidental Take Permit for the Greenbriar project.
As a result of consultation with the USFWS, the HCP for the Greenbriar project could result in different mitigation than is described in the draft BA, conceptual mitigation plan, or the DEIR. The mitigation described in the DEIR, however, establishes a level of mitigation that will be met or exceeded in the HCP. Thus, the HCP will reduce effects to a comparable or lower level than the mitigation analyzed in this effects analysis.
2.3 METHODOLOGY FOR ANALYZING ALTERATIONS OF POPULATIONS
AND HABITATS
2.3.1 C ONSTRUCTION-RELATED EFFECTS ON SURVIVAL AND REPRODUCTION Information regarding the presence of covered species or potentially suitable habitat for these species at the Greenbriar site and adjacent lands was derived from the Greenbriar Draft Environmental Impact Report (DEIR) (EDAW 2005), Greenbriar Draft Biological Assessment (BA) (Berryman Ecological 2005), and a draft conceptual mitigation plan for the project (Wildlands, Inc. 2005). These documents, in turn, were based on site assessments by wildlife biologists and compilation and analysis of the best available data.
Each species was considered to be either likely, possibly, or not affected by construction-activities based on evidence of its presence and of the presence of potentially suitable habitat. Species documented recently (i.e., in the past 5 years) at or adjacent to the Greenbriar or proposed reserve sites were considered to still be using suitable habitat at that site; these species were considered likely to be affected by construction-related activities.
The land area considered adjacent to the Greenbriar or proposed reserve sites differed among species according to their ecology (i.e., their territory and home range sizes, daily and seasonal movements, and their susceptibility to disturbance).
Species not recently documented at or adjacent to the Greenbriar site, but for which potentially suitable habitat has been documented at or adjacent to the site, were considered potentially present and thus individuals of those
Greenbriar Development Project EDAW
City of Sacramento 2-5 Analysis of Effects on the Natomas Basin HCP species may be affected by construction activities. (These species were considered potentially present because surveys performed to date have not been adequate to determine absence of these species.) Species not recently documented at or adjacent to the Greenbriar site, and for which no potentially suitable habitat was located on or adjacent to the site, were considered to not be affected by construction activities.
For species likely to be or possibly affected by construction-related activities, the avoidance and mitigation measures proposed for the Greenbriar project were evaluated. The extent of construction-related effects is reduced through appropriate avoidance and minimization measures. Where combinations of construction activities and affected species and habitats would be similar to those addressed by the NBHCP, this analysis considered the applicable avoidance and minimization measures in the NBHCP (Chapter V) that address construction-related effects to be a complete set of appropriate (and feasible) avoidance and minimization measures for comparable effects potentially caused by the Greenbriar project. Thus, a table of measures in the NBHCP was compiled, measures applicable to the project were identified, and inclusion of each measure in the project and its mitigation was evaluated based on the content of the BA and DEIR for the project. This table was used in evaluating the project’s effects on attainment of NBHCP goals and objectives that address the implementation of avoidance and minimization measures. The analysis also considered the need for different measures to address effects that would be likely and that would differ from those addressed by the NBHCP, and the potential for the Greenbriar project to alter the efficacy of the NBHCP measures (Appendix A).
2.3.2 Z ONES WITH HUMAN-WILDLIFE CONFLICTS
Considerable conflicts between wildlife use and human activities (e.g., animal-vehicle collisions, harassment and predation by pets, degradation of water quality) normally occur in habitat areas adjacent to developed land uses and major roads. These effects diminish with distance, but the distance at which they are no longer significant is debatable.
In this document, the widths used to evaluate human-wildlife conflicts, alterations of vegetation and other habitat conditions, habitat fragmentation, and effects on existing reserves, were based on the ecological literature regarding effects on habitat adjacent to developed land uses and roads, and on the distances used in previous analyses related to the NBHCP or incorporated into the NBHCP itself, The effects of developed land uses on adjacent land diminish with distance. The different types of effects, however, extend different distances onto adjacent land; these distances can be from tens to thousands of feet, and differ not only among mechanisms but among sites as well (because of variation in site attributes such as the presence of barriers and the quantity of impervious surfaces). Thus, in a regional analysis, the use of a specific width only indicates the area within which effects of adjacent developed land are often sufficient to alter habitats.
In the GIS-based evaluations, two widths were used, 800 feet and one mile. The 800-foot width was used in evaluating zones where increased human disturbance, predation from cats and dogs, vehicle collisions, dumping, and alterations to soils, hydrology and vegetation were likely to occur. The one-mile width was used in evaluating the effects on foraging habitat for animals with large home ranges, such as raptors. Both widths are consistent with the ecological literature regarding these effects and the ecology of species in the Natomas Basin, and were previously used in comparable analyses supporting the NBHCP.
The Greenbriar project could cause human-wildlife conflicts in this zone by altering the acreage in the zone (because of an altered perimeter of development) or by altering the intensity of wildlife-human conflicts (because of the avoidance and minimization measures implemented or a change in land cover types in this zone). Change in the extent of the 800-foot wide zone was calculated from the acreage in this zone around the MAP, City of Sacramento and Sutter County permit areas for urban development from the Final NBHCP (City of Sacramento et al. 2003) and around these permit areas plus a developed Greenbriar site. Changes to the intensity of wildlife- human conflicts in the 800-foot wide zone were assessed by calculating changes in land cover types within these zones and by comparing the project’s avoidance and minimization measures with those in the NBHCP that
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP 2-6 City of Sacramento address these conflicts. An increase in land cover providing higher quality habitat (or land cover more sensitive to human disturbance) would increase human-wildlife conflicts, while a decrease in such land cover types would reduce human-wildlife conflicts. Similarly, a less comprehensive or stringent set of measures would increase the intensity of conflicts, while a more comprehensive or stringent set of measures would reduce the intensity of conflicts. Any reduction in the efficacy of specific NBHCP measures addressing human-wildlife conflicts also could increase conflicts; potential effects on the efficacy of these measures were evaluated in Appendix A.
2.3.3 A CREAGE OF HABITAT IN THE NATOMAS BASIN
A major component of the effects analysis in the NBHCP was an analysis of change in habitat acreage. For each covered species, the NBHCP analyzed the habitat that was available under baseline conditions and that would be available in the expected future condition of the Natomas Basin. The NBHCP documented baseline land cover in the Natomas Basin as of 2001. The data sources and methods used to do so are described in Natomas Basin Conservation Plan Impacts to Proposed Covered Species (CH2M HILL 2002) that was attached to the Final NBHCP as Appendix H. The Natomas Basin covers approximately 53,538 acres. The future condition evaluated was the result of developing an additional 17,500 acres of this land in the MAP, City of Sacramento, and Sutter County permit areas and establishing an 8,750–acre reserve system in the Natomas Basin outside of those permit areas. For each covered species, changes in habitat acreages were derived from the changes in the acreage of land cover types by identifying those land cover types that provide habitat for that species. Additional analyses were performed for Swainson’s hawk that included assessment of changes in habitat within 1 mile of existing reserves and nests, quality of foraging habitat, and seasonal availability of foraging habitat.
The Greenbriar project would alter these future conditions by developing additional land and by preserving and enhancing additional land as part of the TNBC reserve system. Thus, for this project’s effects analysis, for each covered species, the future condition of the Natomas Basin with the NBHCP and the Greenbriar project was compared to the future condition analyzed in the NBHCP and to the 2001 NBHCP baseline. For the Greenbriar and proposed reserve sites, these comparisons were based primarily on 2001 land cover to be consistent with and comparable to the NBHCP’s effects analysis, and because 2001 conditions were used as the NBHCP baseline.
These comparisons allow assessment of both the extent of future habitat under the future condition resulting from the NBHCP and under the future condition resulting from the NBHCP plus the Greenbriar project. These were GIS-based analyses. The land cover GIS data layer developed for the NBHCP was the data source for land cover.
This was the available land cover data most applicable to this analysis.
Effects based on 2005 land cover were also quantified and considered. This was done by using aerial photography to update the land cover mapped in 2001 in a manner consistent with the 2001 mapping. This mapping used different criteria and was at a coarser scale than some of the land cover mapping in the BA and DEIR (which was based in part on site surveys by biologists). These differences did not lead to different conclusions regarding the efficacy of mitigation for the project’s effects.
Land cover mapped by Jones & Stokes was also considered in our analyses (Jones & Stokes 2005; Jones & Stokes, unpublished data) (Appendix B). This mapping used different land cover classification and mapping methods from the 2001 mapping by CH2M HILL, which limited its applicability to this analysis. Nonetheless, a crosswalk between the CH2M HILL and Jones & Stokes land cover types was developed and a common classification was derived; after reclassifying both data sets, EDAW estimated land cover changes during 2001– 2004, and used the results to assess overall changes in land cover, implementation of NBHCP conservation strategies on TNBC reserves, stability of agricultural land uses, and fallowing of rice in anticipation of development. This analysis is presented in Appendix B. Its results also were used in the cumulative effects analyses in Section 7 Cumulative Effects.
This assessment indicated that land cover changes since 2001 have occurred primarily within the MAP, City of Sacramento, and Sutter County permit areas for urban development, and at TNBC reserves; the primary land cover changes outside of these areas were an increase in the acreage of rice, a substantial decrease in the acreage
Greenbriar Development Project EDAW
City of Sacramento 2-7 Analysis of Effects on the Natomas Basin HCP of non-rice crops and a corresponding increase in the acreage of fallowed and abandoned cropland. It did not indicate that fallowing of rice in anticipation of development was occurring. Although the dramatic changes in non-rice crop and idle cropland acreages affect the acreage of available habitat for just two covered species (burrowing owl and Aleutian Canada goose), they do illustrate that availability of agricultural habitats can change rapidly in the Natomas Basin; they also indicate that estimates of future availability of agricultural habitats in the NBHCP and in this report represent approximations based on assumptions that may not occur (i.e., that current patterns of agricultural land use are representative of future patterns).
Other GIS data layers used in the analyses included the locations of canals and drains, and the boundaries of the Natomas Basin, NBHCP permit areas, and of the Greenbriar and proposed reserve sites. In our analyses, canal habitats were analyzed differently than in the Final NBHCP. In the Final NBHCP, canals and drains were assigned to four categories (I-IV) based on the width of habitat they provided; of these, only category I canals were included in the land cover layer and categories II-IV were estimated separately. In contrast, we included all habitat along category I-IV waterways in the canal land cover type, Because these canal acreages were included in the canal land cover type in our analyses, the future acreages of land cover types differ somewhat from those presented in the NBHCP.
To assess the future condition of the Natomas Basin with the Greenbriar project, several assumptions were made regarding changes in land cover. These assumptions included the following. ► All land in the MAP, City of Sacramento, and Sutter County permit areas was assumed to be developed, or otherwise no longer providing habitat for covered species. ► Land at the Greenbriar site was assumed to be developed, or otherwise no longer providing habitat for covered species, except for a 250-foot wide corridor along the western edge of the Greenbriar site would be preserved. Land in this corridor would be converted to grassland, except for approximately 2.7 acres of tule marsh that would be created, and 1.4 acres of riparian habitat that was mapped in the conserved corridor in 2001 and would presumably recover and persist in the proposed reserve. ► All other areas were treated as in the effects analysis for the NBHCP, except that 8,750 acres (not including the project’s proposed reserves) would be incorporated into a reserve system. The reserve system would be approximately 25% managed marsh, 50% rice and 25% upland land cover types. For estimating acreage changes, the managed marsh and rice was considered to come out of the baseline rice acreage. ► Under the future condition, land at the project’s proposed reserve sites was assigned to land cover types based on the Greenbriar Draft Conceptual Habitat Restoration Design prepared by Wildlands, Inc. (2005), and subsequent revisions by the project applicant. The mitigation land required by Mitigation Measure 6.13-2 of the DEIR was not included in the GIS analysis because its location has not been determined. ► Preserved land would be dedicated to TNBC (or another nonprofit land trust) and an endowment would be provided for the enhancement, operations, maintenance, and administration of preserved land in perpetuity.) Thus, the future condition that was analyzed assumes that the project, all development proposed under the NBHCP and all associated mitigation would occur, and that current agricultural land uses are representative of future agricultural land uses. These or comparable assumptions were also made in the effects analyses supporting the NBHCP (e.g., sections 3 and 4 of Appendix H of the NBHCP, and Section 2 of Appendix K).
Changes in the acreage of habitat for a covered species were the sum of changes in land cover types providing habitat for that species. The habitat-land cover relationships used in analyses supporting the NBHCP were also applied to analyses for the Greenbriar project. These relationships are summarized in Table 2-1. Vernal pool- associated species were not considered in these analyses because the Greenbriar and proposed reserve sites do not contain vernal pool habitats nor have vernal-pool associated species been documented in the vicinity of these sites.
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP 2-8 City of Sacramento Also, in addition to these analyses of Basin-wide GIS data sets, we also considered more detailed site-specific information provided in the DEIR, BA, and the most recent TNBC monitoring report (Jones & Stokes 2005).
Table 2-1
Species Habitat-Land Cover Relationships
Land Cover Types
Species
Airport
Alfalfa
Canals
Grassland
Highways
Idle
Non-rice Crops
Oak Groves
Orchards
Other
Pasture
Ponds and
Seasonally Wet
Rice
Riparian
Ruderal
Rural
Residential
Tree Groves
Urban
Giant garter snake X X X
Swainson’s hawk (N) X X X
Swainson’s hawk (F) X X X X X X
Burrowing owl X X X X X X
Loggerhead shrike X X X X X X X X X X X X X
Tricolored blackbird (F) X X X X X
Aleutian Canada goose (F) X X X
White-faced ibis X X X X
Bank swallow X X X X X X X X
Valley elderberry longhorn
beetle X
Northwestern pond turtle X X X X
Sanford’s arrowhead X X
Delta tule pea X X
2.3.4 Q UALITY OF HABITAT IN THE NATOMAS BASIN
Changes in habitat quality can result from changes in land cover, connectivity, adjacent land uses, and the preservation and management of land to enhance its habitat quality, changes in connectivity, and adjacent land uses. In this report, changes in the acreage of land cover types providing different quality habitat and changes in the acreage of land preserved and managed to enhance habitat quality were derived from the analyses of change in habitat acreages described in the preceding section (Acreage of Habitat in the Natomas Basin). Changes in habitat quality resulting from changes in connectivity or adjacent land uses were evaluated separately, and these evaluations are described in other sections.
For Swainson’s hawk, the quality and seasonal availability of foraging habitat for Swainson’s hawk were evaluated in a manner comparable to the effects analysis conducted by CH2M HILL for the NBHCP (CH2M HILL 2003). In addition, based on a quantitative model of the relative value of different foraging habitats, EDAW also analyzed the overall quantity of resources provided by foraging habitat in the Natomas Basin with and without the Greenbriar project. Though based largely on similar interpretations of existing information as the CH2M HILL analyses for the NBHCP, this model was developed by EDAW biologists for this effects analysis.
In the analysis conducted for the NBHCP, crops and other land cover types were placed in high, medium and low categories for habitat value. This was done on the basis of previous research (e.g., Estep 1989, Estep and Teresa 1992). Seasonal availability of prey was considered separately by calculating the “monthly availability of
Greenbriar Development Project EDAW
City of Sacramento 2-9 Analysis of Effects on the Natomas Basin HCP potential foraging habitat.” (This analysis of habitat availability was based on the assumption that for row and field crops, prey were only available to hawks at the time of harvest.) Because food resources for Swainson’s hawk vary substantially among land cover and crop types, these analyses provided much more information than a simple tabulation of acres of potential foraging habitat. However, these analyses did not produce an estimate of total foraging resources that would indicate the overall change in habitat. Therefore, in addition to applying the same analysis as CH2M HILL conducted for the NBHCP, EDAW also estimated the total food resource potentially provided by foraging habitat.
In the analyses supporting the NBHCP, alfalfa and idle cropland were considered to be high value habitat; sugar beet, tomato, melons, squash and cucumber, beans, wheat, pastures (clover, unspecified or mixed) and ruderal land was considered moderate value habitat; Corn, safflower, onions and garlic, and unspecified row and field crops were considered low quality habitat.
The temporal availability of prey was also considered in an analysis conducted for the NBHCP. In this analysis, prey was considered inaccessible to Swainson’s hawk during much of the spring and summer because of the dense (and high) cover of vegetation in cultivated fields. In contrast, crops, such as alfalfa, and other land cover types (e.g., grassland) were considered to provide accessible prey for longer periods because of frequent harvests or the vegetation’s growth form. Thus, during the months of April–October, for the different crop types grown in the Natomas Basin, prey was assumed to be accessible only during the months when harvest predominantly occurs. These time periods were June for wheat, July–August for tomato and unspecified crops, August for safflower onions and garlic, September–October for sugar beet, and October for beans, melons, squash and cucumber. (Swainson’s hawks have migrated out of the Natomas Basin by October, and thus crops harvested in October do not provide foraging habitat in the NBHCP analysis.) For crops harvested during periods of two months, the total acreage of these crops was divided by two to determine the acreage of foraging habitat available during each of those months. Grassland, ruderal, idle cropland, and pastures (including alfalfa) were considered to provide habitat throughout April–September.
These analyses regarding habitat value and temporal availability were applied to the Greenbriar project. For this analysis, the habitat value of the Greenbriar, proposed reserve, and DEIR mitigation sites was compared with and without the proposed development and proposed habitat creation, enhancement, and preservation.
For these analyses, the habitat value of the Greenbriar, proposed reserve and DEIR mitigation sites without the Greenbriar project was based on the same data sources as the analysis conducted for the NBHCP (i.e., 1993 DWR mapping of croplands and 2001 land cover mapping by CH2M HILL of the entire Natomas Basin).
The habitat value of the Greenbriar, proposed reserve and DEIR mitigation sites with the Greenbriar project was based on an assumed future condition derived from the project description and mitigation measure 6.13-2 of the DEIR for the project. For this assumed future condition, the acreages of habitats at these sites are presented in Table 2-2. For the Greenbriar site, these assumptions were that the 26.5 acres of preserved grassland that would be created and preserved along Lone Tree Canal would be low quality habitat (because of its proximity to development), and that the rest of the site would not provide any habitat for Swainson’s hawk. For the proposed off-site reserves, these assumptions were that the 59.6 acres of upland at the Natomas 130 and Spangler sites would be alfalfa (or otherwise managed to provide high quality habitat) and that the 59.5 acres of upland components of created marsh would provide moderate quality habitat.
Mitigation measure 6.13-2 of the DEIR, which requires at least 49 acres of land be preserved, enhanced, and managed in perpetuity to provide high quality foraging habitat for Swainson’s hawk so that the project’s proposed mitigation plus this DEIR mitigation would provide equal or greater value to the species than the habitat present at the Greenbriar site in 2005. The location(s) and existing land cover of the Swainson’s hawk foraging habitat that would be required by mitigation measure 6.13-2 have not been determined; this analysis assumed that the current land cover of the mitigation site(s) that would provide foraging habitat for Swainson’s hawk was agricultural land harvested during July–August and providing low quality habitat. As mitigation for the project, it
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP 2-10 City of Sacramento was assumed that this land would be converted to high quality habitat with prey available from April through September. These assumptions represent the minimum acreage at an additional site that would need to be preserved, enhanced, and managed in perpetuity to comply with mitigation measure 6.13-2.
Table 2-2
Habitat Type Acreages Used in Analyses of Effects on Swainson’s Hawk Foraging Habitat Greenbriar Site Proposed Reserves DEIR Mitigation Total Habitat Without
Project
With
Project
Without
Project
With
Project
Without
Project
With
Project
Without
Project
With
Project
Alfalfa - - - 59.6 49 - 108.9
Grassland1 - 26.5 - - - - - 26.5
Idle 62.5 - - - - - 62.5 -
Ruderal 9.2 - - - - - 9.2 -
Pasture 33.8 - - - - - 33.8 -
Upland component of marsh - - - 59.5 - - - 59.5
Field crop – Moderate quality,
harvested September–October
203.7 - 28.4 - - - 232 -
Field crop – Low quality,
harvested July–August
30.4 - - - 49 - 79.4 -
Note:
1 In analysis, this grassland area was considered to be low quality foraging habitat because of its proximity to development.
The EDAW model of Swainson’s hawk foraging habitat uses the same current and assumed future conditions as were used for the NBHCP. The range of habitat quality, however, was divided into four categories, rather than three. These ratings changed seasonally for cropland, and a relative quantitative value was assigned to each category so that the total quantity of food resources potentially available could be estimated. The following text describes EDAW’s methodology for calculating this estimate.
For each month during April–September, each crop and other land cover type providing foraging habitat was assigned to one of four quality ratings: high, high-moderate, moderate, or low. These ratings are given in Table 2-3. Crops and the other land cover types that provide foraging habitat were assigned these ratings on the basis of prey abundance; the accessibility of prey to the hawk; and on the frequency of harvest, flood irrigation, and other activities that create valuable foraging opportunities for Swainson’s hawks, as indicated by the existing literature (Estep 1989, Estep and Teresa 1992). The frequency of harvest, flood irrigation and other activities was considered in rating habitats because of the importance of these activities for hawk foraging. For example, in the radio telemetry study conducted by Estep (1989), approximately half of all Swainson’s hawk foraging was associated with harvest, flood irrigation, and other agricultural activities.
Alfalfa combines a high frequency of mowing and irrigation with low vegetation that leave prey accessible to hawks. For these reasons, this land cover type was rated “high” quality.
Grassland, ruderal, idle cropland, upland components of marsh, and fallowed rice also have low vegetation that leaves prey accessible, and can have prey abundance comparable (or even greater than) alfalfa. However these land cover types lack the frequent cultivation and irrigation activities that provide valuable foraging opportunities, and therefore were rated “high-moderate.”
Row crops with relatively dense vegetation that limits prey accessibility but still allows some foraging throughout the field (e.g., tomato, beets) were rated “moderate.”
Greenbriar Development Project EDAW
City of Sacramento 2-11 Analysis of Effects on the Natomas Basin HCP Dense, tall crops (e.g., corn, wheat) that restrict foraging to field margins were considered “low” quality foraging habitat. Because of its proximity to development, the proposed grassland along Lone Tree Canal also was considered to provide low quality foraging habitat.
Table 2-3
Habitat Quality and Harvest Months for Swainson’s Hawk Foraging Habitats in the Natomas Basin1 Habitat Harvest Month(s) Gr owing Season Quality Harvest Quality Post-Harvest Quality Alfalfa April-Sept High High High
Grassland2 - High-Moderate - -
Idle - High-Moderate - -
Fallowed Rice - High-Moderate - -
Tomato July-August Moderate High Low
Sugar beet September-October Moderate High Low
Beans October Moderate High Low
Squash, pumpkin October Moderate High Low
Upland Marsh - Moderate - -
Pasture - Moderate - -
Ruderal - Moderate - -
Wheat June Low High Low
Unspecified crop July-Aug Low High Low
Safflower August Low High Low
Onions and garlic August Low High Low
Corn September Low High Low
Notes:
1 - Data based on CH2M Hill 2003, except for growing season quality of grassland, idle and fallowed rice, as described in methods section. 2 – Grassland in proposed reserve along Lone Tree Canal was considered to be low quality habitat because of surrounding development.
The harvest of crops makes the relatively high density of prey in cropland much more accessible, and this brief period of high accessibility and high abundance is followed by continued accessibility but rapidly declining abundance. Therefore, crops providing low and moderate quality habitat during the growing season were considered to provide high quality habitat for a two weeks at harvest, and then subsequently their habitat quality was reduced to low. Harvest times were considered to be the same as in the NBHCP analysis (CH2M HILL 2003) and these are listed in Table 2-3. For crops harvested during a two-month period, half of the acreage was assumed to be harvested each month, and for that half of the acreage, the growing season and harvest quality ratings were averaged for that month.
To calculate an estimate of food resources provided by foraging habitats, the value of each habitat type was expressed relative to high quality habitat, which was assigned a value of “1.” These values are an interpretation of the relevant existing scientific literature that includes studies of the use of foraging habitat and relative prey abundance in different crop and other cover types (Estep 1989, Estep and Teresa 1992). Because in low quality habitat, the tall and dense vegetation restricts foraging to field margins, low quality habitats were assigned a value of “0.1.” (However, because harvest makes prey available, the value of these lands is raised to “1” for a two-week interval during the harvest period.) Because the vegetation height and density of moderate quality crops allows some access to prey throughout the field, these crops were assigned a value of “0.3.” (During harvest, moderate
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP 2-12 City of Sacramento quality crops were assigned a “1” rating for a two-week interval, and their rating was subsequently reduced to “0.1”.) Because high-moderate quality foraging habitat has accessible and relatively abundant prey, but not the frequent harvest, flood irrigation, and other activities of high quality habitat, it was assigned a value of “0.5”.
Multiplying the acreage in each habitat quality category by these relative values, and then summing the products, provides an estimate of the total forage available to Swainson’s hawks in the Natomas Basin. The units of this estimate are the equivalent acreage of high quality foraging habitat. These estimates, though rough approximations, provide an explicit, consistent basis for analyzing changes in the quantity of food potentially available to Swainson’s hawk in the Natomas Basin. Estimates were calculated for the Greenbriar, proposed reserve, and mitigation sites with and without the proposed project and DEIR mitigation.
In addition to these analyses, other effects on habitat quality for Swainson’s hawk and giant garter snake also were considered. As in the NBHCP, effects on habitat within 1 mile of recently documented Swainson’s hawk nests (i.e., nests documented in the last 5 years) were considered. For giant garter snake, effects were also considered for upland land cover types that could provide habitat and that were adjacent to canals.
2.3.5 C ONNECTIVITY OF HABITAT IN THE NATOMAS BASIN
The Greenbriar project could affect the connectivity of habitat by eliminating or creating waterways, affecting the use of waterways by covered species, or by altering the length, width, or habitat attributes of existing corridors of natural vegetation. In assessing these effects, several assumptions were made including the following. ► All of the Greenbriar site would be developed, except for a 250-foot wide corridor along Lone Tree Canal. ► All waterways in the developed portion of the Greenbriar site would be eliminated. ► In the absence of avoidance and minimization measures, all waterways and uplands within 800 feet of the Greenbriar, Spangler, or Natomas 130 sites could potentially be affected by the project. (Ecologically significant effects caused by developed land uses were considered to not extend beyond an 800-foot wide zone adjacent to developed land cover and highways, and the basis for selecting this width is further described in Section 2.2.2 Zones with Human-Wildlife Conflicts.)
► At the proposed Spangler and Natomas 130 reserves, waterways would remain except where rice was converted to upland land cover, and land cover would be changed as described in the Draft Conceptual Restoration Plan prepared by Wildlands, Inc. (2005) and subsequent revisions by the project applicant.
Interpretations of effects on connectivity were based on general ecological literature regarding wildlife use of corridors, recent reviews of the ecology of covered species, and consultations with species experts. Along canals, potential changes in physical conditions (e.g., flow regime, culvert dimensions), vegetation structure and extent, human disturbance, and predation were all evaluated as factors potentially altering connectivity.
2.3.6 C ONNECTIVITY OF TNBC RESERVES
The connectivity of TNBC reserves can be altered by altering upland corridors or waterways between existing reserves. Upland corridors are affected by narrowing their width, altering the habitat attributes of the land in them, or by altering their length. The assessment of these potential effects was based on the same assumptions and conducted in the same manner as previously described for Connectivity of Habitat in the Natomas Basin, except that only effects on corridors between existing reserves were considered rather than effects on all lands. (Corridors were considered to not pass through urban land.) We assumed that the most ecologically important upland corridors include the shortest paths between reserves.
Greenbriar Development Project EDAW
City of Sacramento 2-13 Analysis of Effects on the Natomas Basin HCP Waterways are also important corridors connecting TNBC reserves. Thus, altering the location or habitat value of waterways could affect the connectivity of existing reserves. This effect was evaluated by identifying all waterways within 800 feet of the Greenbriar site, and determining if they were part of the shortest path along waterways between reserves, in a corridor between reserves with multiple waterways, or otherwise could be important for species movement between reserves (e.g., species use of the waterway has been documented). We also considered the recent documentation of habitat conditions along canals by Eric Hansen (Jones & Stokes 2005, Eric Hansen, unpublished data). Our analysis of waterways connecting TNBC reserves was based on analysis of GIS data for waterways in the Natomas Basin, and on boundaries of existing TNBC reserves, MAP, City of Sacramento, and Sutter County permit areas, and of the Greenbriar, Spangler, and Natomas 130 sites, and on species distribution data and consultation with knowledgeable individuals. For this analysis, ecologically significant effects of developed land uses and roads were not considered to extend in general beyond an 800-foot zone of adjacent land; the basis for selecting this width is further described in the section describing the evaluation of zones with human-wildlife conflicts.
2.3.7 H ABITAT VALUE OF EXISTING TNBC RESERVES
Changes in adjacent land cover can affect existing TNBC reserves by altering foraging habitat accessible from a reserve or by altering the habitat values of reserve lands through development or preservation of adjacent lands.
Thus, we performed three analyses to evaluate effects on the habitat value of existing TNBC reserves. These analyses are described below.
► The effects of the project on foraging habitat were evaluated based on changes in land cover because of the project within 800 feet and 1 mile of existing reserves. Most effects of developed land uses and roads were considered to not extend beyond an 800-foot wide zone of adjacent land. (The basis for selecting this width is described in the section describing the evaluation of zones with human-wildlife conflicts.) Furthermore, as summarized in Section 4 of this document (Potential Effects of the Greenbriar Project on Covered Species), the territories and home ranges of some covered (and many other) species residing at the reserves are unlikely to extend more than 800 feet from reserve boundaries. However, Swainson’s hawk and other raptors have much larger home ranges and territories; for these species, land within 1 mile of reserves was considered to include the most important habitat for individuals nesting on reserves. (This premise is comparable to that underlying the analysis of Swainson’s hawk habitat in the Natomas Basin presented in Natomas Basin Conservation Plan Impacts to Proposed Covered Species [CH2M HILL 2003] and included in Appendix K of the NBHCP). ► The effects of additional development on habitat values of TNBC reserves were evaluated by calculating the acreage of existing TNBC reserves within 800 feet of additional developed land cover that would result from the project. This 800-foot criterion is the desired distance of reserves from urban land (described on page IV- 16 of the NBHCP) and also includes the area that would experience ecologically significant effects caused by adjacent developed land uses and roads.
► The proximity of the proposed reserves to existing reserves was examined to determine if any were adjacent to existing reserves, and if they expanded the area, increased the habitat variety or reduced the perimeter-to area ratio of the reserve.
2.3.8 W ATER AVAILABILITY AT TNBC RESERVES
The project could alter water availability at TNBC reserves if it were to eliminate sections of canals that are required for water deliveries to TNBC reserves, contribute to the elimination of other canals by affecting demand for water deliveries and increase the land ownership of TNBC and its corresponding water use and ownership of stock in Natomas Mutual.
It was assumed that all canals in developed portions of the Greenbriar site would be eliminated, and that consequently, sections of canal off-site but directly connected to canal segments on the Greenbriar site could be
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP 2-14 City of Sacramento abandoned. The connection of each of these eliminated or potentially abandoned canal segments to TNBC reserves was evaluated, and the effect on water availability to reserves was assessed.
In addition, Natomas Mutual and RD 1000 were contacted regarding waterways that could be eliminated because of the project. Elimination of canals or drains by these water agencies or due to a development project, however, would likely require mitigation under either Section 7 or Section 10 of the Endangered Species Act, and therefore their effects would likely be mitigated even if their elimination occurred separately from the project.
The project’s effect on TNBC stock ownership in Natomas Mutual also was considered. Natomas Mutual is a privately held water company comprised of landowner stockholders. As TNBC acquires mitigation lands in the Natomas Basin, it increases its shares in Natomas Mutual. This increased ownership could result in TNBC changing operations and maintenance practices to support the goals and objectives of the NBHCP. The project would increase TNBC ownership and thus its influence on the operations of Natomas Mutual. The magnitude of this increase in ownership and its likely effects were assessed.
2.3.9 O PPORTUNITIES TO ESTABLISH ADDITIONAL TNBC RESERVES The Greenbriar project could affect opportunities to establish additional TNBC reserves by reducing the acreage of land available for satisfying the mitigation requirements of the development permitted through the NBHCP, or by expanding existing reserves so that more interconnected reserves can be established that exceed the 400-acre minimum desired size. These potential effects were evaluated by estimating the acreage potentially available for NBHCP mitigation with and without the project, and by examining the connectivity of the proposed Spangler and Natomas 130 reserves to existing TNBC reserves.
The acreage potentially available for NBHCP mitigation without the project was estimated by subtracting the following areas from the Natomas Basin’s total acreage of land suitable for preservation followed by restoration or enhancement: MAP, City of Sacramento, and Sutter County permit areas for urban development, the County- owned airport buffer, and levee slopes around the perimeter of the plan area. Land cover considered unsuitable for restoration or enhancement included existing developed land cover outside of permit areas, and other, ruderal and rural residential land cover.
The acreage potentially available for NBHCP mitigation after development of the project was estimated by subtracting the following areas from the acreage potentially available without the project: the proposed Spangler and Natomas reserves and the developed portion of the Greenbriar site (that otherwise would be suitable for preservation). The fragmentation by the project of a block of land that otherwise was potentially suitable for preservation also was considered.
The location of the proposed reserves was examined to determine if these lands expanded existing TNBC reserves, could contribute to the expansion of TNBC reserves in the future or could be expanded into a reserve that was greater than 400 acres in size, or if they were isolated from TNBC reserves by developed lands or other barriers.
2.4 BASIS FOR INTERPRE TATIONS OF EFFECTS ON COVERED SPECIES For each covered species, we evaluated:
► construction-related effects on individuals using the Greenbriar site or adjacent lands, ► change in habitat quantity, and
► change in habitat quality.
For this evaluation, the available information on the ecology and distribution of each covered species was compiled, reviewed, and summarized. Interpretations of construction-related effects on individuals were based on the analysis of the likely alterations of survival and reproduction of individuals using the Greenbriar site or
Greenbriar Development Project EDAW
City of Sacramento 2-15 Analysis of Effects on the Natomas Basin HCP adjacent lands. Interpretations of effects on habitat availability were based on the analysis of alterations to habitat acreage that was described previously.
Interpretations of change in habitat quality were based on the analyses of land cover acreages and connectivity of habitat in the Natomas Basin, and of the acreage in zones with human activity-wildlife conflicts. We also considered changes in the acreage of preserved lands, and in the acreage of high quality habitat.
For each covered species, the interpretations of effects on habitat acreage and quality (and of construction-related effects and human-wildlife conflicts) were used to evaluate the project’s overall effect on the viability of the population using the Natomas Basin. A population’s viability (i.e., its likelihood of long-term persistence) is strongly influenced by population size, population demography, and environmental variability (which in turn has a strong influence on reproduction and mortality). In the Natomas Basin, fluctuations in the acreage of crop types and changes in agricultural practices cause substantial environmental variability affecting the populations that rely on agricultural habitats. By reducing the quantity or quality of habitat, urban development can reduce population size and adversely affect demography.
2.5 BASIS FOR INTERPRETATI ONS OF EFFECTS ON NBHCP
CONSERVATION STRATEGY
The previously described analyses of effects on population and habitat attributes, and on covered species, were used to evaluate the potential effect of the Greenbriar project on the effectiveness of the NBHCP conservation strategy. This strategy is described in Section IV.C of the NBHCP. This section describes six key components of the NBHCP’s conservation strategy for effectively mitigating 17,500 acres of urban development. These components are:
► basis for 0.5 to 1 mitigation ratio (Section IV.C.1.a), ► preparation of site specific management plans (Section IV.C.1.b), ► buffers within the reserve lands (Section IV.C.1.c),
► connectivity (Section IV.C.1.d),
► foraging habitat (Section IV.C.1.e), and
► 2,500-acre/400-acre minimum habitat block size requirements (Section IV.C.1.f).
Potential effects of the Greenbriar project on each of these components was assessed individually (using the results of the analyses described in Section 2.3 Methodology for Analyzing Alterations of Populations and Habitats); these effects were then synthesized into an overall effect of the Greenbriar project on the effectiveness of the NBHCP’s conservation strategy.
2.6 BASIS FOR INTERP RETATIONS OF EFFECTS ON HCP GOALS AND
OBJECTIVES
The NBHCP’s goals and objectives represent the desired outcomes from implementation of the NBHCP’s conservation strategy. Nine of the NBHCP’s goals and objectives could be affected by the Greenbriar project.
Table 2-4 lists these goals and objectives; it also identifies the population and habitat attributes potentially affected by the project that could affect attainment of the NBHCP’s goals and objectives. This effects analysis evaluated the effects of the Greenbriar project on each of these nine goals and objectives of the NBHCP.
Interpretations of the project’s overall effect on the attainment of a goal or objective were based primarily on the sum of these anticipated effects. Substantial effects (beneficial or adverse) could alter the viability of a covered species or interfere with attainment of a goal or objective. Effects that would reduce the viability of a covered species, preclude attainment of a goal or objective, or otherwise result in a change to the NBHCP’s conservation strategy were considered significant effects that would conflict with the NBHCP.
EDAW Greenbriar Development Project
Analysis of Effects on the Natomas Basin HCP 2-16 City of Sacramento
Table 2-4
Relationships Between Applicable NBHCP Goals and Objectives and Attributes Potentially Affected by the Greenbriar Project1 Species and Habitat Attributes
NBHCP Goals and Objectives
Survival and reproduction
of individuals using Project
Site or adjacent lands
Zones with human-wildlife
conflicts
Acreage of habitat in
Natomas Basin
Connectivity of habitat in
Natomas Basin
Connectivity of existing
TNBC reserves
Habitat value of existing
TNBC reserves
Water availability at TNBC
reserves
Opportunities to establish
additional TNBC reserves
Overall Goal 1. Establish and manage in perpetuity a biologically sound and interconnected habitat reserve system that mitigates impacts on Covered Species resulting from Covered Activities and provides habitat for existing, and new viable populations of Covered Species. (NBHCP page I-15)
- - X X X X X X
Overall Goal 3. Preserve open space and habitat that may also benefit local, non- listed and transitory wildlife species not identified within the NBHCP. (NBHCP page I-16)
- - X X X X X X
Overall Goal 4. Ensure that direct impacts of Authorized Development upon Covered Species are avoided or minimized to the maximum extent practicable. (NBHCP, page I-16)
X - - - - - - -
Overall Objective 1. Minimize conflicts between wildlife and human activities, including conflicts resulting from airplane traffic, roads and automobile traffic, predation by domestic pets, and harassment by people. (NBHCP, page I-16)
X X - - - - - -
Overall Objective 3. Ensure connectivity between TNBC reserves to minimize habitat fragmentation and species isolation. Connections between reserves will generally take the form of common property boundaries between reserves, waterways (primarily irrigation and drainage channels) passing between reserves, and/or an interlinking network of water supply channels or canals. (NBHCP, page I-16)
X X X X
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City of Sacramento 2-17 Analysis of Effects on the Natomas Basin HCP Table 2-4
Relationships Between Applicable NBHCP Goals and Objectives and Attributes Potentially Affected by the Greenbriar Project1 Species and Habitat Attributes
NBHCP Goals and Objectives
Survival and reproduction
of individuals using Project
Site or adjacent lands
Zones with human-wildlife
conflicts
Acreage of habitat in
Natomas Basin
Connectivity of habitat in
Natomas Basin
Connectivity of existing
TNBC reserves
Habitat value of existing
TNBC reserves
Water availability at TNBC
reserves
Opportunities to establish
additional TNBC reserves
Wetland Species/Habitat Goal/Objective 1. Acquire, enhance and create a mosaic of wetland habitats with adjacent uplands and connecting corridors to provide breeding, wintering, foraging, and cover areas for wetland species in the Plan Area. (NBHCP, page I-17)
X X X X X
Wetland Species/Habitat Goal/Objective 2. Provide habitat to maintain, attract and sustain viable populations of the Covered Species. The habitat areas should be configured to encompass natural species migration areas, minimize species isolation, and prevent future habitat fragmentation. (NBHCP, page I-17) - X X X X X X X
Upland Species/Habitat Goal/Objective 1. Acquire, enhance and create a mosaic of upland habitat types for breeding, foraging, and cover for species dependent on upland habitats. (NBHCP, page I-17)
- - X - - X - X
Upland Species/Habitat Goal/Objective 2. Ensure reserve land connectivity with travel corridors for upland-dependent species. The habitat areas should encompass grasslands, agricultural croplands, riparian habitats, and shelter and nesting habitat areas (fence rows, clusters of shrubs and small trees), as well as wetland areas to provide a year-round source of water for upland species. The upland areas should be configured to enhance natural species migration, minimize species isolation, and prevent future habitat fragmentation. (NBHCP, page I-17) - - - X X X - X
Note:
1 An “X” indicates that alteration of that species or habitat attribute could directly affect attainment of that goal or objective.
Greenbriar Development Project EDAW
City of Sacramento 3-1 Analysis of Effects on the Natomas Basin HCP 3 GREENBRIAR PROJECT’S ALTERATION OF POPULATION
AND HABITAT ATTRIBUTES
3.1 CONSTRUCTION-RELATED EFFECTS ON SURVIVAL AND
REPRODUCTION
Based on CNDDB, surveys of the Greenbriar site, and other data on the distribution of species in the Natomas Basin, species covered by the NBHCP that likely use the Greenbriar site include Swainson’s hawk, burrowing owl, loggerhead shrike and giant garter snake. For these species, construction at the Greenbriar site could affect the survival and/or reproduction of individuals by killing, injuring or disturbing individuals, or by eliminating habitat that those individuals depend on for food or shelter. These potential effects are summarized below and described in detail in the sections addressing potential effects for each covered species.
Nesting Swainson’s hawks could be affected by the project’s construction activities. Though no Swainson’s hawk nests have been documented on the Greenbriar, Spangler or Natomas 130 sites, five nests have been recently documented within one mile of the Greenbriar site, 12 nests within one mile of the proposed Natomas 130 reserve (where marsh habitat would be constructed), and 59 nests in the Natomas Basin (Jones & Stokes 2005).
Swainson’s hawks at any of these nest sites might have their reproduction and survival affected to some degree by construction of the project, and those at the nest sites within one mile could have reduced nesting success or abandon their nest. To avoid and minimize these potential effects, the project includes the same measures that were included in the NBHCP to avoid and minimize construction-related effects on Swainson’s hawk. An evaluation of the applicability of NBHCP measures and their inclusion in the Greenbriar project and its mitigation is presented in Appendix A. (These measures are also comparable to those incorporated into the MAP HCP [which has been superseded by the 2003 NBHCP].)
Burrowing owls nesting on or near and foraging on the Greenbriar site could be affected by the project’s construction activities. A burrowing owl has been observed on the Greenbriar site. Other burrowing owls could be residing on adjacent land, and any residing within about a mile of the Greenbriar site also could be foraging on the Greenbriar site. Construction of the project could cause nest abandonment or trap or injure owls in their burrows.
To avoid and minimize these potential effects, the DEIR mitigation includes the same measures that were included in the NBHCP to avoid and minimize construction-related effects on burrowing owls. An evaluation of the applicability of NBHCP measures and their inclusion in the Greenbriar project and its mitigation is presented in Appendix A. (These measures are also comparable to those incorporated into the MAP HCP [which has been superseded by the 2003 NBHCP].)
Loggerhead shrikes nesting on or near (i.e., within a quarter-mile) and foraging on the Greenbriar site could be affected by the project’s construction activities. Shrikes were observed on the Greenbriar site during March 2005 surveys. Because shrikes are distributed throughout the Natomas Basin and suitable habitat is present, shrikes also could be present at the proposed Natomas 130 reserve (where marsh habitat will be constructed). Construction of the project could cause nest abandonment. To avoid and minimize this potential effect, the project includes the same measures that were included in the NBHCP to avoid and minimize construction-related effects on loggerhead shrike. An evaluation of the applicability of NBHCP measures and their inclusion in the Greenbriar project or the DEIR mitigation is presented in Appendix A. (These measures are also comparable to those incorporated into the MAP HCP [which has been superseded by the 2003 NBHCP].) Giant garter snakes foraging or residing on the Greenbriar site could be affected by the project’s construction activities. Giant garter snakes have been observed along Lone Tree Canal, which provides high quality habitat for this species; the other canals on and bordering the Greenbriar site, and the uplands adjacent to these canals, also provide habitat for giant garter snake. The proposed reserve sites also contain or are bordered by giant garter snake habitat. Because giant garter snakes in the Natomas Basin travel widely (i.e., several miles or further)
Greenbriar Development Project EDAW
City of Sacramento 3-2 Analysis of Effects on the Natomas Basin HCP during their daily and seasonal movements, the Lone Tree Canal is an important movement corridor for this species, and the Greenbriar site contains suitable habitat, giant garter snakes could be killed or injured during construction activities.
The construction activities associated with the Greenbriar project would be comparable to those covered by the NBHCP, as are the species and habitats affected by these activities. Therefore, the applicable measures from the NBHCP would be appropriate for avoiding and minimizing this project’s construction-related effects, and the project includes the same measures that were included in the NBHCP to avoid and minimize construction-related effects on giant garter snake. The DEIR (EDAW 2005) also proposes additional measures to avoid and minimize construction-related effects on giant garter snake including exclusion fencing erected prior to the onset of the dormant season preceding construction, routine monitoring of giant garter snakes stranded on the interior (i.e., construction side) of the fence, and documentation and reporting of mortality with the provision to modify avoidance and minimization measures to prevent future moralities due to similar causes.
3.2 ZONES WITH HUMAN- WILDLIFE CONFLICTS
As described in the methodology, areas within 800 feet of the MAP, City of Sacramento, or Sutter County permit areas, or major highways, were considered to be areas with high levels of potential human-wildlife conflicts. The Greenbriar project would reduce the total area, and the area of most land cover types, in these zones, and would include measures to reduce effects on adjacent habitats, but it would increase the area of rice and managed marsh within 800 feet of urban development or major highways. Overall, the project with the DEIR mitigation would not significantly increase human-wildlife conflicts in the Natomas Basin.
3.2.1 F UTURE CONDITIONS UNDER THE NBHCP
Under the future conditions resulting from implementation of the NBHCP, a portion of the Greenbriar site would be adjacent to urban development or major highways, and thus potentially experiencing high levels of human- wildlife conflicts. Urban development would be adjacent to the Greenbriar site along its eastern and western sides and part of its southern side (Exhibit 1). Lone Tree Canal and Lone Tree Road would be between the Greenbriar site and urban development to the west. Highway 99 would separate the site from the urban development to the east. Along the site’s southern side, Interstate 5 would be between the site and both urban development and the agricultural or natural vegetation remaining to the southwest. Along the site’s northern boundary, Elkhorn Boulevard would be a six land road between the Greenbriar site and agricultural or natural land cover to the north.
The expansion of Elkhorn Boulevard was authorized by the MAP HCP, and although in this analysis it was not considered urban development or a major highway that would generate high levels of human-wildlife conflicts, it would increase levels of human-wildlife conflicts.
Under the future conditions resulting from implementation of the NBHCP, the proposed Spangler reserve would be bordered to the north by development in Sutter County’s permit area. A portion of the Natomas 130 parcel would be within 800 feet of urban development in the City of Sacramento’s permit area, but would be separated from it by Fisherman’s Lake.
3.2.2 P OTENTIAL EFFECTS OF GREENBRIAR PROJECT UNDER FUTURE CONDITION Development of the Greenbriar project would reduce the area of habitat in zones with potentially high levels of human-wildlife conflicts. This counter-intuitive result would occur because the project would develop portions of the Greenbriar site that would otherwise be in such zones, and would create smaller new zones with potentially high levels of human-wildlife conflicts. Under the future condition resulting from the NBHCP, about 230 acres of the Greenbriar site would be within 800 feet of urban development or major highways. Development of the Greenbriar site would eliminate most of this acreage and would create a new, but smaller, zone with potentially high levels of human-wildlife conflicts north of the Greenbriar site (about 62 acres in size), because this
Greenbriar Development Project EDAW
City of Sacramento 3-3 Analysis of Effects on the Natomas Basin HCP undeveloped land would be within 800 feet of urban land after development of the project. The net change would be a reduction of 137 acres in the extent of areas with high levels of human-wildlife conflicts.
Though land to the north would be adjacent to development on the Greenbriar site, a six-lane road (Elkhorn Boulevard) would be between this land and residential development on the Greenbriar site. The road would partially isolate the Greenbriar site from land to the north, and thus limit human-wildlife conflicts resulting from the Greenbriar Project.
Nonetheless, the project would increase the area of rice and managed marsh that is within 800 feet of urban development or a major highway, and thus increase the area of giant garter snake, northwestern pond turtle and white-faced ibis habitat in zones with potentially high levels of human-wildlife conflicts. In the 2001 land cover map, the area within 800 feet of the northern border of the Greenbriar site was primarily in rice (53 of 62 acres).
This acreage was greater than the 47 acres of rice on the Greenbriar site that were within 800 feet of the MAP or City of Sacramento permit areas. Thus, based on 2001 land cover for the Greenbriar site, the acreage of rice in areas with high levels of human-wildlife conflicts would increase as a result of developing the Greenbriar site. In addition, up to about 14.2 acres of managed marsh could be created at the proposed Natomas 130 reserve within 800 feet of the City of Sacramento’s permit area for urban development, and at the proposed Spangler reserve about 37 acres of the created marsh could be within 800 feet of the Sutter County’s permit area. At the proposed reserves, on-site buffers and reserve management (e.g., limiting access) would reduce human-wildlife conflicts, and the proposed Natomas 130 reserve is separated from urban development in the City of Sacramento by Fisherman’s Lake, which also would limit human-wildlife conflicts.
Compared to the total area of land in the Natomas Basin that is within 800 feet of a major highway or of the MAP, City of Sacramento, or Sutter County permit areas, these changes are relatively small. There is approximately 2,790 acres of land outside of the three permit areas but within 800 feet of such areas or of a major highway. Thus, the Greenbriar project would reduce the area of these zones by about 5%. Similarly, there are roughly 1,420 acres of rice and managed marsh in these zones, and the Greenbriar project would increase this area by 4% (52 acres).
Without mitigation, the Greenbriar project also could increase human-wildlife conflicts along Lone Tree Canal.
Under the future condition resulting from the NBHCP, a 1.1 mile section of the Lone Tree Canal would be within 800 feet of urban development; these urban land uses and highways would be adjacent to one bank of the canal except at road crossings. Development of the project would place urban land uses within 200 feet of the other bank of Lone Tree Canal as well. The Lone Tree Canal is an important corridor for animal movement, particularly for giant garter snake. The project’s potential effects on this canal, and measures to reduce those effects, are discussed in detail in Section 3.4 Connectivity of Habitat in the Natomas Basin.
The project and its mitigation would also implement measures to reduce human-wildlife conflicts. The project includes all of the applicable measures incorporated into the NBHCP to avoid and minimize human-wildlife conflicts. An evaluation of the applicability of NBHCP measures and their inclusion in the Greenbriar project or the DEIR mitigation is presented in Appendix A. To further reduce human-wildlife conflicts along Lone Tree Canal, the project also would implement a comprehensive set of measures including fencing and a barrier. These measures are described in more detail under Section 3.4 Connectivity of Habitats in the Natomas Basin and would be further developed during the HCP process.
Overall, the Greenbriar project, with the DEIR mitigation, would not cause a significant increase in human- wildlife conflicts in the Natomas Basin. This is in part because much of the Greenbriar site is, or under NBHCP and MAP permit conditions would be, bordered by urban development, highways, and major roads under the future condition, and in part because of the measures incorporated into the project and the DEIR mitigation.
Greenbriar Development Project EDAW
City of Sacramento 3-4 Analysis of Effects on the Natomas Basin HCP
3.3 HABITAT ACREAGE IN THE NATOMAS BASIN
The project would reduce the acreage of habitat available in the Natomas Basin for several species covered by the NBHCP. These losses would result from changes in land cover at the Greenbriar and proposed reserve sites.
3.3.1 C HANGE IN HABITAT ACREAGE AT THE GREENBRIAR SITE The Greenbriar project would alter the Greenbriar and proposed reserve sites. Most of the Greenbriar site would be converted to urban land cover (Exhibit 2, Table 3-1). But, a 30.6 acre area along the western edge, bordering the Lone Tree Canal, would be conserved. This area would be preserved, restored as tule marsh (approximately
2.7 acres) or native grassland, and added to the TNBC reserve system. (The existing, disturbed patch of riparian land cover [at the southern end of this conserved area] would probably recover and persist.) Table 3-1
Land Cover Acreages of Greenbriar Project
Greenbriar Site1 Proposed Spangler & Natomas
130 Reserves2 Total
Land Cover Types
2001 2005 Post-
Project 2001 2005 Post-
Project 2001 2005 3 Post-
Project
Alfalfa - - - - - 59.6 59.6
Canals 15.0 15.0 - 7.6 7.6 6.2 22.6 22.6 6.2
Grassland - - 26.5 - - - - - 26.5
Idle 62.5 115.1 - - 28.4 - 62.5 143.5 -
Non-rice crops 234.1 381.0 - 28.4 - - 262.6 381.0 -
Pasture 33.8 - - - - - 33.8 - -
Ponds & seasonally
wet areas - 1.7 2.7 - - 198.2 - 1.7 200.9
Rice 160.0 - - 228 228 0 395.4 228 0
Riparian 1.4 1.4 1.4 1.6 1.6 1.6 3.0 3.0 3.0
Roads and Highways 17.5 17.5 - - - - 17.5 17.5 -
Ruderal 9.2 2.0 - - - - 9.2 2.0 0
Rural Residential 43.3 43.3 - - - - 43.3 43.3 -
Tree Groves - - - 0.2 0.2 0.2 0.2 0.2 0.2
Urban - - 546.4 - - - - - 546.4
Total 577 577 577 265.8 265.8 265.8 842.8 842.9 842.9
Note:
1 The Greenbriar site included the 30.6 acre area along Lone Tree Ca nal that would become a preserve and 546.4 acres that would be developed. Lone Tree Canal was considered immediately adjacent to but outside of the project site. 2 Reserve acreages do not include the additional preservation and enhancement of upland habitats required by mitigation measure 6.13- 2 of the DEIR because location, acreage, and current land cover of this land has not been determined. 3 These 2005 acreages differ from those in the DEIR because they were based on a GIS analysis comparable to that performed for 2001 (as described in the methods) and the DEIR acreages were based on a different analysis that included a field survey of the site.
If the Greenbriar site were to remain predominantly in agricultural land cover, a variety of crops probably would be cultivated on it and portions of the site would be idle in many years. Land cover in 2001 and 2005 indicates the range of habitat values the Greenbriar site could provide over the long-term, and thus that would be lost by the site’s development. In 2001, the site contained idle, pasture, ruderal, canal, rice, riparian, non-rice crops, and rural residential land cover (Table 3-1). In 2005, pasture and rice were no longer present and the area of idle and non- rice cropland had expanded.
Greenbriar Development Project EDAW
City of Sacramento 3-5 Analysis of Effects on the Natomas Basin HCP Estimates of habitat loss depend on whether they are based on 2001 or 2005 land cover. For some species (e.g., giant garter snake), estimates of habitat loss would be greater if based on 2001 land cover than if based on 2005 land cover. For other species (e.g., Swainson’s hawk), estimates of habitat loss would be greater if based on 2005 land cover. For evaluating how the project would alter the future condition of the Natomas Basin, changes from 2001 land cover were used because 2001 land cover was the baseline for the NBHCP’s estimates of future habitat conditions.
Although different analyses were conducted for this effects analysis and for the DEIR, both considered 2001 and 2005 conditions. To evaluate the proposed project’s effects on the effectiveness of the NBHCP, this effects analysis performed an extensive analysis of the project’s potential effects on the future condition of the Natomas Basin. This analysis used the 2001 land cover data that represents baseline conditions of the NBHCP, and also considered 2001–2004 changes in land cover, and 2005 conditions. To comply with CEQA requirements and to assure that the proposed project does not compromise the effectiveness of the NBHCP, the impact analysis in the DEIR evaluated conditions documented in 2005 when the Notice of Preparation (NOP) was released, and provides mitigation designed to reduce impacts to less than significant under both 2005 conditions (for CEQA purposes) and 2001 conditions (to assure that the project does not compromise the effectiveness of the NBHCP).
3.3.2 C HANGE IN HABITAT ACREAGE AT PROPOSED RESERVE SITES Land cover would also be altered at the proposed reserve sites (Table 3-1). Approximately 45 acres of the Spangler site would be converted to upland foraging habitat (assumed to be alfalfa), 184 acres would be converted to marsh that would include upland components, and about 6 acres would be canal. At the Natomas 130 site, about 14 acres that were in non-rice crops in 2001, and are currently idle, would be converted to marsh, about 2 acres would remain in riparian habitat, and the remaining 14 acres at this site would be managed as foraging habitat for Swainson’s hawk. The location and existing land cover of the mitigation site(s) providing at least an additional 49 acres of Swainson’s hawk foraging habitat (to fulfill mitigation measure 6.13-2 of the DEIR) have not been specified, and thus the effects of these land cover changes are not included in Tables 3-1, 3-2 and 3-3.
However, this mitigation needs to provide high quality habitat for Swainson’s hawk, and so land would probably be converted from non-rice crops to alfalfa (or otherwise be managed to provide high quality foraging habitat).
3.3.3 O VERALL CHANGE IN HABITAT ACREAGE
Together, these changes at the Greenbriar and proposed reserve sites, but not including additional DEIR mitigation for Swainson’s hawk, would reduce the acreage of several natural or agricultural land cover types that provide habitat for covered species, and would increase the acreage of alfalfa, grassland, and of ponds or seasonally wet areas (Table 3-2).
Based on 2001 land cover, these changes represent a reduction in habitat acreage for most species that use non- rice cropland and other upland land cover, a net gain of habitat for two plant species that grow in wetlands and along canals, and a net loss for species using both canal and rice land cover (Table 3-3, which does not include additional DEIR mitigation for Swainson’s hawk). (No change in the acreage of vernal pool or riparian habitats would result from the project.) Except for burrowing owl, the covered species that forage in non-rice crops and other upland land cover (Swainson’s hawk, loggerhead shrike, tricolored blackbird, Aleutian Canada goose, and bank swallow) would lose from about 14 to 684 acres of habitat. Because the acreage of created marsh habitats would be much greater than the acreage of lost canal habitats, potential habitat for Sanford arrowhead and delta tule pea (which occur in marsh or canal habitats) would increase by 184 acres.
The acreage of habitat would decrease for white-faced ibis, giant garter snake, and northwestern pond turtle by 144–204 acres, because the loss of rice and canal habitats would be greater than the acreage of marsh created from non-habitat (Table 3-3).
Greenbriar Development Project EDAW
City of Sacramento 3-6 Analysis of Effects on the Natomas Basin HCP Table 3-2
Change in Land Cover Acreage Because of Natomas Basin HCP and Greenbriar Project Future Condition Resulting from NBHCP Plus Project1, 2, 3, 4 Land Cover Natomas
Basin 20011
Future Condition
Resulting from
NBHCP1, 2 2001 Greenbriar Land Cover 2005 Greenbriar Land Cover Airport 1,532 1,492 1,492
(0)
1,492
(0)
Alfalfa 368 368 427
(60)
427
(60)
Canals 1,753 1,162 1,146
(-16)
1,146
(-16)
Grassland 882 284 311
(27)
311
(27)
Highway or Major
Road
1,353 770 753
(-18)
753
(-18)
Idle 1,449 422 360
(-63)
307
(-115)
Non-rice Crops 16,395 9,533 9,271
(-263)
9,152
(-381)
Oak Grove 94 77 77
(0)
77 (0)
Orchard 178 165 165
(0)
165
(0)
Other 460 314 314
(0)
314
(0)
Pasture 660 494 460
(-34)
494
(0)
Ponds & Seasonally
Wet Areas
93 2,259 2,460
(201)
2,458
(199)
Rice 22,129 11,643 11,255
(-388)
11,415
(-228)
Riparian 115 91 91
(0)
91 (0)
Ruderal 1,882 370 361
(-9)
368
(-2)
Rural Residential 369 287 244
(-43)
244
(-43)
Tree Grove 102 44 44
(0)
44 (0)
Urban 3,725 23,763 24,309
(546)
24,309
(546)
Total 53,538 53,538 53,538 53,538
Notes:
1 Acreage along Class II-IV canals included in ac res of canals, thus reducing acreages in other categories from those given in NBHCP. 2 Acreages include changes in land cover occurring at proposed Spangler and Natomas 130 reserves. 3 Change in acreage from future condi tion of NBHCP is in parentheses. 4 Changes resulting from the preservation and enhancement of upland habitat required by Mitigation Measure 6.13-2 are not included in these acreages.
Greenbriar Development Project EDAW
City of Sacramento 3-7 Analysis of Effects on the Natomas Basin HCP Table 3-3
Change in Habitat Acreage Because of Natomas Basin HCP and Greenbriar Project Future Condition Resulting from NBHCP Plus Project1, 2, 3, 4 Species Natomas
Basin 20011
Future Condition
Resulting from
NBHCP1, 2 2001 Greenbriar Land Cover 2005 Greenbriar Land Cover 5 Giant garter snake 23,975 15,064 14,860
(-204)
15,019
(-45)
Swainson’s hawk
(Nesting)
311 211 211
(0)
211
(0)
Swainson’s hawk
(Foraging)
6 21,636 12,018 11,796
(-222)
11,638
(-380)
Burrowing owl6 6,994 3,647 3,673
(24)
3,631
(-16)
Loggerhead shrike 24,339 15,555 15,415
(-141)
15,254
(-301)
Tricolored blackbird
(foraging)
40,434 22,322 21,724
(-598)
21,799
(-523)
Aleutian Canada goose 39,184 21,670 20,986
(-684)
21,061
(-609)
White-faced ibis 24,343 15,432 15,228
(-144)
15,446
(-14)
Bank swallow 42,395 25,834 25,420
(-414)
25,494
(-340)
Valley elderberry
longhorn beetle
115 91 91
(0)
91 (0)
Northwestern pond
turtle
24,090 15,155 14,951
(-204)
15,110
(-45)
Sanford’s arrowhead 1,846 3,421 3,605
(184)
3,604
(183)
Delta tule pea 1,846 3,421 3,605
(184)
3,604
(183)
Notes:
1 Acreage along Class II-IV canals were included in acres of canals, thus reducing acreages in other land cover categories from those given in NBHCP as baseline conditions; this altered habitat estimates as well. 2 Acreages include changes in land cover occu rring at proposed Spangler and Natomas 130 reserves, and assume that land in MAP, City of Sacramento, and Sutter County permit areas would not provide habitat under future conditions. 3 Change in acreage from future conditi on because of NBHCP is in parentheses. 4 Changes resulting from the preservation and enhancement of addi tional upland habitat to satisfy Mitigation Measure 6.13-2 are not included in this table’s acreages because the acreage, location, and current land cover of this land has not been specified. 5 2005 habitat acreages differ from those in the DEIR because different methodologies were used; this effects analysis relied on a GIS analysis comparable to analyses of 2001 land cover, whereas the DEIR used by GIS analyses and field surveys by biologists .to estimate habitat acreages.
6 For these species future c ondition acreages also include upland components of created marshes.
3.4 HABITAT QUALITY IN THE NATOMAS BASIN
Besides these changes in habitat acreage, changes in the quality of the remaining habitat also would occur. In part, changes in habitat quality result from changes in the acreage of land cover types providing lower or higher habitat quality. For example, the project would increase ruderal land cover that provides habitat for Swainson’s hawk, burrowing owl, and loggerhead shrike, but this habitat is of lesser quality than that provided by other land cover types, including types whose acreage was reduced by the project (e.g., idle cropland). Similarly, marshland
Greenbriar Development Project EDAW
City of Sacramento 3-8 Analysis of Effects on the Natomas Basin HCP created by the project would provide higher quality habitat for some species (e.g., northwestern pond turtle and white-faced ibis) than the canal habitats eliminated by the project.
3.4.1 H ABITAT QUALITY ADJACENT TO THE GREENBRIAR SITE
Habitat quality would be reduced on land adjacent to development at the Greenbriar site. Roads, urban, and exurban development detrimentally affect the provision of wildlife habitat and other ecosystem functions on adjacent lands. These effects are caused by a wide variety of mechanisms that include alteration of hydrology, water quality, disturbance regimes, and vegetation structure, and the introduction of non-native species, collisions with vehicles, noise disturbance, and harassment by humans, and predation by cats, dogs, and wildlife associated with human land uses. The distance that effects on wildlife habitat extend from developed land varies with the mechanism causing the effect, the species affected, and attributes of the development and its surrounding landscape, but distances may range from less than 10 to over 1,000 feet (De Snoo and de Wit 1998, Forman and Alexander 1998, Paul and Meyer 2001, ELI 2003, Miller et al. 2003, Allan 2004). The most likely causes of effects on adjacent habitats because of the project are:
► Decreased runoff to and lower water levels in Lone Tree Canal, ► Spread of non-native invasive species,
► Harm and harassment by humans, cats, and dogs,
► Dumping of trash,
► Increased levels of noise and nighttime light, and
► Loss of upland vegetation adjacent to canals.
Several of these effects on wildlife habitat could extend hundreds of feet from the site. Although the mechanisms by which development affects habitat are well understood, a moderate level of uncertainty exists regarding the magnitude and location of the effects resulting from specific development projects (including the Greenbriar project). The degradation of habitat on adjacent lands is also assessed in the sections of this report that address zones with high levels of human-wildlife conflicts and those addressing effects on covered species.
In addition, the habitat quality of adjacent agricultural lands would be altered by changes in crop types or the cessation of agriculture. Land cover on adjacent land north of the Greenbriar site could possibly change because of conflicts between rice cultivation and the residential development created by the project. Aerial application of pesticides and herbicides probably is not feasible immediately adjacent to residential development (C. Aubry, pers. comm.), which could cause part, or all, of the adjacent parcel to be removed from rice cultivation. The North Natomas Community Plan has reduced these conflicts through a 350-foot wide buffer of open space along roads separating developed and agricultural land uses (EDAW 2005). Similarly, the Metro Air Park includes a 250-foot wide buffer along its northern and eastern borders in which developed land uses are restricted to open space, warehouses, or parking areas (USFWS 2001). The Greenbriar project would not contain an open space buffer along its borders between its development and adjacent land uses, and the only buffer would be Elkhorn Boulevard, which would be a six lane road. The project would include notification of all prospective residents and tenants within 500 feet of existing agricultural uses describing the types of agricultural operations that could occur in proximity to their homes or businesses (DEIR mitigation measure 6.11-3). Nonetheless, agricultural-residential conflicts could occur.
The extent of potential conflicts is not known. If all agricultural use of land within 350 feet of the project’s residential development were to cease, roughly 23 acres of rice would become idle land. This would increase the project’s effects on giant garter snake, and on other species associated with rice but not idle land, and would decrease the project’s effects on Swainson’s hawk and other species associated with idle land but not rice.
However, other scenarios are equally plausible, and it would be speculative to quantify the habitat that could be affected, and base mitigation on that estimate.
Greenbriar Development Project EDAW
City of Sacramento 3-9 Analysis of Effects on the Natomas Basin HCP In addition to these local effects, development also degrades wildlife habitat through landscape-scale effects on the distribution of habitat. These effects are described in sections of this report addressing effects on connectivity, the habitat value of existing reserves, and on covered species.
3.4.2 H ABITAT QUALITY AT PROPOSED RESERVES
Habitat quality would be increased through preservation and management of at least 345 acres at the Spangler, Natomas 130, Greenbriar, and DEIR mitigation sites. Habitat quality would increase at these sites because:
1. Habitat would be preserved in perpetuity;
2. Habitat would be monitored and actively ma naged for the benefit of covered species;
3. Habitat would not be subject to c ontinuous disturbance caused by farming or canal maintenance activities; and
4. Habitat would be relatively free of human intrusion (USFWS 2003).
In addition to the increase in habitat quality resulting from preservation, habitat quality would be increased at the proposed reserves as a result of habitat enhancement and conversion to land cover types that provide higher quality habitat.
As part of the proposed project, at the Spangler site, 184 acres of rice at the Spangler site and 14 acres of upland at the Natomas 130 site would be converted to marsh that provides higher quality habitat, and would be managed to increase habitat quality for covered species, particularly giant garter snake. Managed marsh provides substantially greater habitat values for giant garter snakes than does rice for several reasons. These reasons include:
► Giant garter snakes primarily use the margins of rice fields, whereas they use the full extent of managed marshes. These marshes are designed to provide open water, foraging habitat, dense cover, basking sites, and refugia in close proximity throughout the marsh. (For example, an acre of managed marsh provides several times the edge habitat than does a rice field.)
► Marshes provide habitat throughout the active period of the snake. Rice fields do not provide habitat during early and mid-spring, and are typically drained before the end of the snake’s active period. Thus, for a portion of their active period, giant garter snakes must rely entirely on non-rice habitats. In the Natomas Basin, these habitats are canals and managed marsh. In contrast, managed marshes provide habitat year-round. ► Rice is fallowed periodically, and thus does not provide habitat in all years; in contrast, a managed marsh does provide habitat in all years.
The quality of existing upland habitats also would be enhanced at the proposed reserves and the DEIR mitigation site(s). Upland habitat at the proposed Spangler and Natomas 130 reserves would be enhanced, and additional mitigation land (at least 49 acres) would be enhanced through conversion to alfalfa (or would be otherwise managed to provide high quality foraging habitat for Swainson’s hawk).
However, some uncertainty exists regarding the magnitude of habitat enhancement that would result from the project. For example, marsh creation would be used to replace habitat values lost at the Greenbriar site because marsh has greater habitat value than rice. (The general basis for this scenario is repeatedly outlined in the NBHCP, EIR, and BO.) And, for the reasons given previously, this difference in habitat value is inferred to be substantial. But, studies have not yet been conducted that document this difference in habitat value between managed marsh and rice. Furthermore, most marshes created by TNBC are only several years old, and the habitat attributes of created marsh changes rapidly during their first few years. Therefore, the long-term results of marsh creation and management have not yet been determined. Currently, it is known that giant garter snakes are using created marshes to some extent, our understanding of giant garter snake’s ecology supports arguments that marsh
Greenbriar Development Project EDAW
City of Sacramento 3-10 Analysis of Effects on the Natomas Basin HCP provides substantially higher quality habitat than rice (and higher quality than canals), and preserved lands are more likely to continue to provide habitat than unpreserved lands.
The effects of changes in the quality of habitat provided by enhanced and preserved land, are further described in the sections of this report that address potential effects on each covered species.
3.4.3 H ABITAT QUALITY FOR SWAINSON’S HAWK FORAGING
The effects of the Greenbriar project on the quality of Swainson’s hawk foraging habitat was evaluated through three analyses: acres of foraging habitat in low, moderate and high quality categories; total acres of foraging habitat available per month; and total foraging habitat available each month expressed as an equivalent acreage of high quality foraging habitat. The first two analyses (acres by habitat quality category and monthly availability) were conducted as in the NBHCP, and the third was developed for this evaluation of the Greenbriar project. All three methods are described in detail in the methods section. The acres of habitat types at the Greenbriar, proposed reserve and DEIR mitigation sites with and without the project that were used in these analyses of effects on Swainson’s hawk foraging habitat are shown in Table 2-2.
The project would result in a net loss of habitat acreage but an increased percentage of the remaining habitat would be in the high quality category (Exhibit 3a). This increase in high quality habitat would result from enhancement of habitat at the Spangler, Natomas 130, and the DEIR mitigation sites. Upland habitat at the proposed Natomas 130 reserve would be enhanced, and high quality foraging habitat would be created at the proposed Spangler reserve and to satisfy the DEIR mitigation at least 49 acres of land would be enhanced and managed to provide high quality foraging habitat for Swainson’s hawk.
Based on the analysis approach in the NBHCP, the project would result in greater availability of foraging habitat during April–September, despite causing a net loss in overall acreage of habitat (Exhibit 3b). (However, this approach assumes that row and field crops are not available to foraging hawks except at harvest, and thus underestimates the acreage of foraging habitat available, particularly during April–May, which is prior to the harvest of row and field crops in the Natomas Basin.)
Based on EDAW’s evaluation approach, total foraging resources would be comparable with and without the project. At the Greenbriar, proposed reserve, and DEIR mitigation sites, during April–June, slightly greater foraging resources would be available with the project (the equivalent of 129 acres of high quality foraging habitat with versus 122 acres without the project), while during July–September there would be less (129 versus 140 acres in July–August and 162 acres in September) (Exhibit 4). (Throughout the Natomas Basin, during July– September, more foraging resources are available because that is when most crops are harvested [CH2M HILL 2003].)
3.5 CONNECTIVITY OF HABITA T IN THE NATOMAS BASIN
The Greenbriar project would cause adverse and beneficial effects on connectivity of habitats in the Natomas Basin. By developing the Greenbriar site, it would fragment habitats for loggerhead shrike, burrowing owl, Swainson’s hawk, and the other covered bird species, which would adversely affect connectivity. It also could cause detrimental effects on connectivity because of human disturbance and predation on giant garter snake and northwestern pond turtle using habitat along Lone Tree Canal. However, the project and the DEIR mitigation include measures to reduce human disturbance and predation effects resulting from the project, and to create and enhance habitat along Lone Tree Canal, which would beneficially affect connectivity of canal and marsh habitats.
In addition, the proposed reserves would increase connectivity of habitats for giant garter snake and northwestern pond turtle. Further, the project would ensure the long-term conservation of a corridor along a segment of Lone Tree canal. This canal is important for maintaining connectivity of canal habitats between the southern and northern Natomas Basin, but a corridor along the canal has not yet been preserved.
Greenbriar Development Project EDAW
City of Sacramento 3-11 Analysis of Effects on the Natomas Basin HCP 0 100
200
300
400
Low Moderate High
Swainson's Hawk
Habitat Quality
Acres
2001
Post-Project
A) Total acres of high, moderate, and low quality habitat at the project and mitigation sites; quality assessed as in CH2M Hill 2003.
Availability of Swainson's Hawk Foraging Habitat
0 100
200
300
April May June July Aug Sep
Month
Acres
2001
Post-project
B) Acres of foraging habitat availabl e by month; availability of prey assessed as in CH2M Hill 2003.
Notes: Estimates are based on approach used by CH2M Hill to support the NBHCP.
Sources: Wildlands 2005, DWR 1993, and CH2M Hill 2001
Quality and Availability of Swainson’s Hawk
Foraging Habitat at the Project and Mitigation Sites Exhibit 3
Greenbriar Development Project EDAW
City of Sacramento 3-12 Analysis of Effects on the Natomas Basin HCP Total Swainson's Hawk Foraging Habitat
0 50
100
150
200
April May June July Aug Sep
Month
Equivalent High Quality Acre 2001
Post-project
Low, moderate, high-moderate, and high quality habitats were combined in an estimate of the acreage of high quality habitat providing equivalent foraging resources, as described in the methods section.
Sources: Wildlands 2005, DWR 1993, and CH2M Hill 2001
Total Swainson’s Hawk Foraging Habitat Exhibit 4
Overall, the project (with the mitigation included as part of the project design and with the DEIR mitigation) is unlikely to significantly reduce connectivity of habitat for covered bird species. Depending on the location, land cover, and management of the mitigation land providing foraging habitat for Swainson’s hawk, the project could cause small, but significant, effects (adverse or beneficial) on connectivity of habitat for covered bird species.
The following sections provide a detailed description of the Greenbriar project’s effects on connectivity at the regional and local levels, and along Lone Tree Canal. This section also evaluates the effect of the Greenbriar project on the implementation of the connectivity measures in the NBHCP’s conservation strategy.
3.5.1 O VERVIEW OF EXISTING AND FUTURE CONDITIONS
In 2001 and currently, the proposed Greenbriar site provides agricultural and canal habitats, as do some adjacent lands. However, because the Greenbriar site is bordered to the south and east by Interstate 5 and State Route 99, respectively, habitats for less mobile animals, or those highly sensitive to human disturbance, are at least partially isolated from similar habitats to the east or south. Birds, including covered species, can fly over these highways.
The Greenbriar site’s canal habitats are connected to similar habitats to the south by a culvert under Interstate 5 through which Lone Tree Canal flows, and the site’s canal habitats are also connected to habitats north of the site by Lone Tree Canal and a culvert in the northeastern corner of the site. These culverts may limit animal movement from the southern to central Natomas Basin across the site. Nonetheless, Lone Tree Canal currently
Greenbriar Development Project EDAW
City of Sacramento 3-13 Analysis of Effects on the Natomas Basin HCP provides a movement corridor and habitat for giant garter snake. In recent years, flows in the canal have not been optimal for giant garter snake, although the Metro Air Park HCP provides assurances that at least some water will be present in this drainage canal in the future (see pages 70-71 in Thomas Reid Associates 2001). The other canals within and along the southern and eastern borders of the Greenbriar site also have recently provided (or still provide) some habitat for giant garter snake, and they may also serve as a movement corridor. Lone Tree Canal is the primary remaining corridor for movement of giant garter snakes between the southern and central portions of the Natomas Basin (C. Aubry, pers. comm.; E. Hansen, pers. comm.). Loss of this corridor could isolate the southern portion of the Natomas Basin, dividing the current giant garter snake population into two smaller populations, which would substantially reduce the likelihood of giant garter snakes persisting in the Natomas Basin.
Under the future condition (i.e., assuming development as permitted under the NBHCP), the Greenbriar site would occupy much of one of two remaining corridors connecting the southern and central Natomas Basin.
Except for these two corridors, the Sacramento International Airport, Metro Air Park and City of Sacramento would separate the southern and central Basin (Exhibit 1). A western corridor, between the airport and the Sacramento River, would be 0.4–1.6 miles wide. This western corridor may not contain sufficient canal, rice and wetland habitats to provide for connectivity of populations of giant garter snake, western pond turtle and other wetland and aquatic species between the southern and central portions of the Natomas Basin. To the east, another corridor would pass between the Metro Air Park and the City of Sacramento. At Interstate 5, this corridor would be about 0.4 miles wide and at the northern end of the Greenbriar site it would be almost a mile wide. In this eastern corridor, the Lone Tree Canal, which passes under Interstate 5, would be an important waterway, and possibly the only waterway, connecting habitats in the southern and central Natomas basin (Jones & Stokes 2005; C. Aubry, pers. comm.; E. Hansen, pers. comm.); this canal has a north-south orientation along the western edge of this corridor.
Under the future condition, the proposed Spangler and Natomas 130 reserves would be outside of but adjacent to permit areas where development has been authorized. The northern border of the proposed Spangler reserve would be immediately adjacent to development in the Sutter County permit area. The eastern border of the proposed Natomas 130 reserve would be across Fisherman’s Lake from development in the City of Sacramento’s permit area.
3.5.2 C ONNECTIVITY OF AQUATIC, WETLAND, AND RICE HABITATS WITHIN THE
NATOMAS BASIN
Within the Natomas Basin, aquatic, wetland, and rice habitats are connected by a series of irrigation and drainage canals. Most of these waterways are suitable for use and movement of a variety of animals, including giant garter snake and western pond turtle, and thus provide movement corridors for these animals between wetland and rice habitats.
In the Natomas Basin, irrigation water is provided by Natomas Central Mutual Water Company (Natomas Mutual), a private water company. Natomas Mutual diverts water from five locations along the Sacramento River and the Natomas Cross Canal, and distributes this water throughout the Basin through a series of canals and pump stations.
Drainage and flood control is provided by Reclamation District (RD) 1000, a public agency. RD 1000 operates the primary drainage canals within the Natomas Basin and is responsible for conveying and pumping nonurban stormwater runoff from the Basin. Runoff from agricultural lands within the Natomas Basin flows into numerous local drainage ditches that ultimately flow into the primary RD 1000 canals. RD 1000’s primary system of interior drains includes the following:
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City of Sacramento 3-14 Analysis of Effects on the Natomas Basin HCP ► The East Drainage Canal conveys drainage water from the northern and eastern Natomas Basin to its confluence with the Main Drainage Canal northwest of the Interstate 80 (I-80)/Interstate 5 (I-5) interchange.
At its closest point the East Drainage Canal is approximately 1.8 miles east of the Greenbriar site. ► The West Drainage Canal conveys drainage water from the western Natomas Basin northwest of Sacramento International Airport to its confluence with the Main Drainage Canal. Fisherman’s Lake, a natural slough, is a portion of the West Drainage Canal. The West Drainage Canal is approximately 3,000 feet (0.6 mile) south of the Greenbriar site at its closest point across I-5, just before the drainage canal turns south toward Fisherman’s Lake.
► The Main Drainage Canal conveys the combined flows of the East and West Drainage Canals from their confluence northwest of the I-80/I-5 interchange through South Natomas west of I-80. Drainage water from the Main Drainage Canal is pumped into the Sacramento River approximately 5 land miles to the south (downstream) of the Greenbriar site.
► The North Drainage Canal is an interior canal that conveys drainage water from the Sutter County portion of the Natomas Basin northward, where it is pumped into the Natomas Cross Canal. ► The Cross Canal conveys drainage water from central portions of Sutter County westward to the Sacramento River. The Cross Canal connects with the Sacramento River approximately 7.1 miles north of the Greenbriar site.
► The Natomas East Main Drainage Canal conveys drainage water from Dry Creek, Arcade Creek, and a large portion of the Natomas area north of the confluence with Dry Creek. The Natomas East Main Drainage Canal is also referred to as Steelhead Creek. The Natomas East Main Drainage Canal outfalls to the Sacramento River at the northern edge of Discovery Park and near the confluence of the Sacramento River and American River approximately 5.2 miles south of the Greenbriar site.
These primary drainage canals are significant corridors of aquatic habitat to which the entire drainage network is connected. Exhibit 5 graphically depicts this primary drainage system.
Although the canal network hydrologically connects aquatic and wetland habitats throughout the Natomas Basin, roads impede or block the movement of many animals through aquatic or wetland habitats. Even for animals that could attempt crossing a road surface, such as turtles and snakes, major roads are effectively impassable (Forman et al. 2003, Dodd et al. 2004, Aresco 2005). For major roads, passage is restricted to the culverts through which the canal waters flow. Culverts are themselves obstacles to animal movement; although a wide variety of animals will move through culverts, for most species, the frequency of these movements is low (Yanes 1995, Rodriguez et al. 1996, Clevenger et al. 2001, Forman et al. 2003, Ng et al. 2004). In general, the use of culverts decreases with their length and with the presence of fencing or debris pits (Yanes 1995, Rodriguez et al. 1996, Clevenger et al. 2001, Forman et al. 2003, Ng et al. 2004). Nonetheless, regular animal crossings (including by other species of garter snake) have been documented through even long culverts that are comparable to those under I-5 (see Forman et al. 2003, Ng et al. 2004, Dodd et al. 2004). Conversely, the use of culverts increases with presence of adjacent habitat or cover, roadside fencing that “funnels” animals towards culverts, and with increased visibility through the culvert (Yanes 1995, Rodriguez et al. 1996, Clevenger et al. 2001, Forman et al. 2003, Ng et al. 2004).
Within the Natomas Basin, Interstate 5 (I-5) and State Route 99 (SR 99) are major barriers to animal movement that are crossed by only a few long culverts. Thus, habitat south of I-5 (i.e., in the southern Natomas Basin), such as at Fisherman’s Lake, is partially isolated from habitat north of I-5. Similarly, habitats west of SR 99 (i.e., in the northwestern Natomas Basin), such as at Pritchard Lake, are partially isolated from habitat east of SR 99 (i.e., in the northeastern Natomas basin), such as Snake Alley.
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City of Sacramento 3-15 Analysis of Effects on the Natomas Basin HCP
Source: CH2M Hill, EDAW 2005
Canals and Drains of Natomas Basin Exhibit 5
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City of Sacramento 3-17 Analysis of Effects on the Natomas Basin HCP In 2001 and presently, habitats east and west of SR 99 are linked by culverts on the V Drain, R Drain, H1 Drain, and Central Main Canal; each of these canals in turn connects to a series of drains and ditches.
In 2001, aquatic habitats north and south of I-5 were linked through culverts by the West Drainage Canal, the N Drain (parallel to Powerline Road), and the Lone Tree Canal. The West Drainage Canal passes north under I-5 to the west of the airport. The N Drain and Lone Tree Canal pass north under I-5 to the west and east of MAP where each is connected to a series of ditches, drains, and canals (including Meister Canal) throughout the northwestern portion of the Basin, and to the culverts under SR 99 to the northeastern portion of the Basin. After it passes under Interstate 5, the N Drain, via Powerline Ditch, also connects giant garter snake habitats south of I-5 to those in the northwestern portion of the Basin.
However, as the development authorized by the MAP HCP and the NBHCP has occurred, and will occur, the system of canals connected to the culverts under I-5 has been changing and will continue to change. Except for the West Drainage Canal, all corridors connecting giant garter snake habitats in the southern Natomas Basin to habitats north of I-5 pass through or drain the MAP, and thus they all will be altered under the future condition of the Natomas Basin permitted by the NBHCP. Development authorized by the MAP HCP and NBHCP will eliminate the Powerline Ditch, No. 4 and 4a ditches, and Meister Canal, eliminate water sources to the Airport East Ditch, and replace the open Central Main Canal with an underground pipe. It also will affect habitat along Lone Tree Canal by reducing the area of land draining into Lone Tree Canal, placing urban development along one side of the canal, and widening Elkhorn Boulevard to six lanes (Thomas Reid Associates 2001, USFWS 2002). (The widening of Elkhorn will not increase the length of the culvert, which is already 115 feet long, but it will increase its diameter from 2.5 feet to 4 feet.
Thus, under the future condition permitted by the NBHCP, giant garter snake habitat south of Interstate 5 would be largely isolated from habitat north of Interstate 5. Two possible corridors would remain: the West Drainage Canal and Lone Tree Canal. Both corridors could connect important habitats in the southern Natomas Basin (such as Fisherman’s Lake which is along the West Drainage Canal) with those in the northwestern and northeastern portions of the Basin. Along both of these potential corridors, there will be obstacles to giant garter snake movement. Both waterways will pass under Interstate 5 through long culverts (over 300 feet long). The West Drainage Canal currently has limited connection to other waterways north of Interstate 5; in the future, it will probably remain isolated because zones of canals and drainage ditches that are currently not suitable habitat for giant garter snake will likely continue to separate it from habitats north and east of the airport. Lone Tree Canal will pass through a culvert under Elkhorn Boulevard (115 feet long). Development of the Metro Air Park will also affect water flow within Lone Tree Canal, however, the MAP HCP includes provisions under changed circumstances (pages 70-71 in Thomas Reid Associates 2001) that address these effects if water levels are less than 12 inches.
Even if snake movement along these north-south corridors were a rare event, this movement would be very important. It would allow genetic interchange between the Basin’s northern and southern subpopulations of giant garter snake, and it would allow giant garter snakes to reestablish in the southern Natomas Basin if that smaller subpopulation were to become extirpated (e.g., due to environmental fluctuations or demographic stochasticity).
Thus, although the relative importance for connectivity of the Lone Tree Canal was not described in the NBHCP, the opportunity for giant garter snakes to move along Lone Tree Canal will be important for the viability of the giant garter snake population in the Natomas Basin.
Under the future condition permitted by the NBHCP at the Greenbriar site, water in Lone Tree Canal would flow south under Elkhorn Boulevard through a 4-foot diameter culvert 115 feet long. It would then flow in a waterway 12 feet wide at the bottom and about 6 feet deep. Along this waterway, set back 25 feet from its western bank will be a low wall 3 feet high, on the other side of which will be Lone Tree Road and commercial and industrial development. Along the eastern bank will be agricultural, ruderal, or natural vegetation. This vegetation would extend for nearly a mile and if cultivated it would include waterways that irrigate and drain the area. At the
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City of Sacramento 3-18 Analysis of Effects on the Natomas Basin HCP southern end of the Greenbriar site, water from the Metro Air Park would enter the canal, and together these waters would flow into three 8-foot by 5-foot box culverts and two 6.5-foot diameter pipes, and pass under Interstate 5.
For this section of Lone Tree Canal between the Interstate 5 and Elkhorn Boulevard culverts, the Greenbriar project would alter these future conditions. The following description of conditions under the future condition with the Greenbriar project is based on the description of the Greenbriar project in the DEIR, BA, the draft conceptual mitigation plan for the project and mitigation measure 6.13-1 of the DEIR. Water would still flow through a 4-foot diameter culvert 115 feet long under Elkhorn Boulevard; there would still be a low wall and development along the western shore, and water would still enter from the Metro Air Park and then flow under Interstate 5 through three 8-foot by 5-foot box culverts and two 6.5-foot diameter pipes. However, near the center of this section of Lone Tree Canal, there would be an additional road crossing (100 feet wide with a 50-foot span that would be 7 feet in height) where Meister Way would cross the canal and an additional road crossing where residential Street 3 would cross the canal (a 53-foot wide crossing). (These crossings would be designed to minimize obstacles to giant garter snake movement [as described in mitigation measure 6.13-1 of the DEIR].) Also, along the eastern bank would be strip (a bench) of tules and other emergent vegetation. This strip of marsh and open water would be relatively narrow; grassland would be on its far side, and within 250 feet of the water flowing in the canal would be a barrier wall and fence separating the corridor along the canal from residential development to the east. There would also be fencing and a wall along Meister Way where it crossed the corridor of managed vegetation along Lone Tree Canal.
This corridor of vegetation along the eastern bank, and the associated structures, would be developed, preserved, maintained, monitored, and adaptively managed by TNBC or another 503(C)(1) organization. This management would be funded by an endowment sufficient for this purpose provided along with the fee title to TNBC (or another 503(C)(1) organization if necessary) which will be established through the process of developing an HCP for the project.
Flows within the canal would also be maintained. The MAP and Greenbriar projects would reduce the area draining into Lone Tree Canal. However, the MAP HCP contains assurances that sufficient water will be maintained in Lone Tree Canal to provide aquatic habitat (as described on pages 70-71 in Thomas Reid Associates 2001), and the Greenbriar project provides an additional assurance that suitable aquatic habitat will be maintained (as described in mitigation measure 6.13-1 of the DEIR).
3.5.3 P OTENTIAL CONSEQUENCES OF THE GREENBRIAR PROJECT FOR FUTURE
CONNECTIVITY
Development of the Greenbriar site, and the creation, enhancement and preservation of habitat at the proposed reserves, could affect the connectivity of habitats at local and regional scales. At a local scale, both development and habitat enhancement/restoration alter the spatial distribution of habitat. Development reduces connectivity and the quantity of habitat accessible to individuals on nearby lands, increases the distance individuals must travel to meet their needs for food and shelter, and increases the risks individuals are exposed to during these movements. Conversely, the enhancement and creation of habitat can increase connectivity, by creating larger areas of contiguous habitat, increasing the food and shelter provided by habitat, or by facilitating movement of individuals. The preservation and active management for habitat values also can maintain connectivity.
POTENTIAL EFFECTS ON CONNECTIVITY AT A LOCAL SCALE
Development of the Greenbriar site would adversely affect connectivity of some habitats at a local scale. At this scale, development of the Greenbriar site would reduce the quantity and contiguity of habitat available to individuals of some species using this site and adjacent lands. These individuals would lose part or all of the habitat in their home ranges or territories, and the remaining habitat could be split into separate pieces (i.e., fragments) that would be isolated by development, or require increased risk and energetic cost to access. This
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City of Sacramento 3-19 Analysis of Effects on the Natomas Basin HCP fragmentation of habitat would occur along the northern and southern borders of the Greenbriar site where lands would not be developed under the future condition resulting from the NBHCP, and it would occur along the western border for those species still able to use the remaining corridor of land as habitat. Habitat fragmentation attributable to the Greenbriar project could affect all covered species, except those associated with vernal pools.
For example, both burrowing owl and loggerhead shrike currently use the Greenbriar site; after development of the project, patches of habitat for these species would be smaller in size and separated by greater widths of non- habitat.
Conversely, the connectivity of habitats at a local scale would be increased by the creation, enhancement, and preservation of habitat at the proposed Spangler and Natomas 130 reserves, and at the unidentified DEIR mitigation site(s) providing the Swainson’s hawk foraging habitat. For example, the marsh created at the Natomas 130 site would be in close proximity to similar habitats at Fisherman’s Lake, and the adjoining TNBC Cummings Reserve (Exhibit 5). Based on the evaluation contained in this effects analysis, on balance, the proposed project would not adversely affect habitat connectivity within the Natomas Basin.
POTENTIAL EFFECTS ON CONNECTIVITY AT A REGIONAL SCALE
At a regional scale, development can create barriers that isolate areas of otherwise suitable habitat or can subdivide a population into two smaller, and thus less viable, populations. Conversely, habitat creation and enhancement as a result of a conservation strategy associated with development can reduce or eliminate barriers, and can increase connectivity at a regional scale.
In the absence of effective mitigation, development at the Greenbriar site could adversely affect habitat connectivity at a basin-wide scale. Land use at the Greenbriar site could affect connectivity of the southern and central Basin, because it occupies one of the two corridors of habitat that would remain under the future condition resulting from the NBHCP.
The Greenbriar project would convert this site to urban land cover except for a 250-foot wide zone that would remain along the Lone Tree Canal and patches of ruderal habitat east of the Greenbriar site (Exhibit 2). In addition, this remaining habitat along Lone Tree Canal would be crossed by Meister Way and Street 3, which would be new roads that connect the developed Greenbriar site to Lone Tree Road. This development would reduce connectivity of the southern and central Natomas Basin for some species.
If connectivity of habitats were reduced at the Greenbriar site, relatively few species would be adversely affected.
First, most species in the Natomas Basin are abundant, widely distributed and highly mobile. (The species observed during monitoring for TNBC support this characterization [Jones & Stokes 2005].) This is largely a consequence of the Natomas Basin being primarily an agricultural (and developed) landscape that is frequently disturbed. Second, Interstate 5 (which is along the entire southern border of the site), and adjacent development to the east and west, already reduces use of the site as a movement corridor by terrestrial animals that are less mobile or are highly sensitive to human disturbance.
The species most likely to be adversely affected at a regional scale by a reduction in connectivity across the Greenbriar site are species dependant on the aquatic or wetland habitat in and immediately adjacent to canals.
This is because under the future condition resulting from the NBHCP, there will be few corridors (or perhaps only this one) along canals between the southern and central Natomas Basin, none of which is likely to provide for relatively high levels of movement and dispersal. In particular, in the absence of comprehensive and effective avoidance, minimization, and mitigation measures to offset its effects, development at the Greenbriar site could cause substantial adverse effects on habitat connectivity for the giant garter snake.
At a regional scale, the mitigation for the Greenbriar project also could improve connectivity of wetland and rice habitats in the northern Natomas Basin through its enhancement of habitat at the proposed Spangler reserve, and in the southern Natomas Basin through its creation of marsh habitat at the proposed Natomas 130 reserve. These
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City of Sacramento 3-20 Analysis of Effects on the Natomas Basin HCP sites are connected to the regional system of waterways; thus, the restoration, enhancement and preservation of habitat at these sites could facilitate the movement of covered species along these waterways. This effect, while less important than effects at the Greenbriar site, could still be significant.
The potential effects on connectivity of giant garter snake habitat are further evaluated in the following section.
POTENTIAL EFFECTS ON CONNECTIVITY OF GIANT GARTER SNAKE HABITAT AT THE GREENBRIAR SITE The effects analysis for the connectivity of giant garter snake habitats are based on several assumptions including:
1. Giant garter snakes currently use Lone Tree Canal at th e Greenbriar site and are likely to continue to do so under the future condition resulting from the NBHCP;
2. Occasionally snakes cross through the culverts under Interstate 5;
3. The frequency of crossings under Inters tate 5 is affected by the extent that snakes use the adjacent sections of Lone Tree Canal;
4. The level of snake use is affected by the habita t features provided by Lone Tree Canal and immediately adjacent land (i.e., movement along the canal is not independent of habitat availability and condition along the canal); and
5. Mitigation for other projects affec ting Lone Tree Canal south of Interstate 5 and north of Elkhorn Boulevard would sustain giant garter snake habitat along those segments of Lone Tree Canal.
In the absence of effective mitigation to maintain or improve connectivity, the Greenbriar project could substantially affect the use of Lone Tree Canal (and of the entire Greenbriar site) by giant garter snakes. The project would:
► eliminate canals and natural vegetation within the Greenbriar site, ► create additional road crossings of Lone Tree Canal at Meister Way and Street 3, ► create residential development within 250 feet of Lone Tree Canal, and ► reduce the acreage draining into Lone Tree Canal (potentially reducing flow in the canal).
In the absence of mitigation, these changes could affect giant garter snake use of Lone Tree Canal. Developing agricultural land at the Greenbriar site would directly eliminate habitat that provides prey, cover, basking sites, and refugia. Additional obstacles, increased predation, and increased human activities all could degrade the quality of remaining habitat, increase mortality and reduce snake use of this segment of Lone Tree Canal.
To offset the effects resulting from these changes and to retain giant garter snake habitats and the movement corridor along Lone Tree Canal, the project would have to:
► Assure that water would be provided in the canal to maintain adequate aquatic habitat, ► Minimize effects on giant garter snake movement at the crossings of Meister Road and Street 3, ► Maintain vegetation and conditions along the canal and in adjacent uplands to meet requirements for giant garter snake use and movement, and
► Reduce the effects of human disturbance, mortality from vehicle collisions, and predation by the cats, dogs, and wildlife associated with developed land uses.
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City of Sacramento 3-21 Analysis of Effects on the Natomas Basin HCP Thus, measures would need to include:
► Providing some water to the canal in perpetuity or otherwise ensuring that adequate aquatic habitat would be maintained,
► Restricting adjacent land uses to allow only those compatible with provision of snake habitat, barriers to human and animal use of the site,
► Designing the Meister Road and Street 3 crossings to minimize impediments to snake movement (e.g., maximize cross-sectional area of and visibility across the canal crossing), ► Incorporating barriers that prevent giant garter snake access to developed areas and visually screening developed areas, and
► Funding site maintenance and management of habitat along the canal and on adjacent land.
The Greenbriar project with applicant-proposed and DEIR mitigation, includes such a set of measures. Measures in the DEIR include:
a. To ensure that the project does not diminish habitat connectivity for giant garter snake between the southwest and northwest zones identified in the NBHCP, approximately 30.6 acres along Lone Tree Canal shall be protected and managed as giant garter snake habitat. This on-site habitat preservation shall protect an approximately 250-foot wide corridor of giant garter snake habitat that includes the canal and approximately 200 feet of adjacent uplands. Uplands within the linear open space/buffer area shall be managed as perennial grassland as described below. Additional aquatic habitat for giant garter snake shall be created along the east bank of Lone Tree Canal by construction and maintenance of a 2.7 acre tule bench. The habitat shall be managed in perpetuity as high-quality habitat for giant garter snake. Compliance and biological effectiveness monitoring shall be performed and annual monitoring reports prepared within six months of completion of monitoring for any given year. This monitoring, reporting, and adaptive management shall be performed as described in Section IV of the NBHCP.
b. To ensure that the project does not diminish gian t garter snake movement along Lone Tree Canal, all new road crossings of Lone Tree Canal shall be designed to minimize obstacles to giant garter snake movement.
The use of culverts under new road crossings on Lone Tree Canal shall be prohibited unless it can be demonstrated that the culverts will not diminish the potential for giant garter snake movement through the section of Lone Tree Canal protected by the setback fence and conservation easement. . c. Upland giant garter snake habitat within the Lone Tree Canal linear open space/buffer area shall be created and managed to provide cover, basking areas, and refugia during the winter dormant period. Hibernaculae would be constructed at regular intervals by embedding concrete or coarse rock in the bank or in a berm along the Lone Tree Canal corridor to provide additional winter refugia. Upland habitat with the linear open space/buffer areas shall be converted to native perennial grassland and managed, in perpetuity, as perennial grassland habitat.
d. Aquatic habitat shall be maintain ed throughout the giant garter snake active season in Lone Tree Canal, in perpetuity. This is the legal responsibility and obligation of Metro Air Park property owners (MAP). The MAP HCP includes provisions for maintaining water in the canal such that the basic habitat requirements of the giant garter snake are met. The MAP HCP also provides a road map, through “Changed Circumstances”, to address procedures to follow if water is not being maintained in the canal to meet these requirements. As described in the MAP HCP, the MAP is legally obligated to assure these requirements are met, and financial and procedural mechanisms are included in the MAP HCP to enforce this. It is, therefore, assumed that MAP will provide water to Lone Tree Canal, as required by the MAP HCP and ITP, in perpetuity. It is also assumed that USFWS will use all reasonable means available to it, to enforce this MAP HCP requirement. If
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City of Sacramento 3-22 Analysis of Effects on the Natomas Basin HCP water is not provided to Lone Tree Canal by the MAP to meet the habitat requirements of giant garter snake, as required by the MAP HCP, and USFWS exhausts its enforcement responsibilities, the project applicant shall assume the responsibility of providing suitable giant garter snake aquatic habitat throughout the section of Lone Tree Canal protected by the fence and conservation easement. However, as stated herein, the project applicant shall only assume this responsibility if it has been sufficiently demonstrated to the City that USFWS has exhausted all reasonable means to compel MAP to comply with the relevant conditions of the MAP ITP.
Specific requirements related to ensuring suitable aquatic habitat in Lone Tree Canal is present, in perpetuity, throughout the giant garter snake active season shall be developed through consultation with DFG and USFWS, and included in the new or amended HCP for Greenbriar, and may include mechanisms, such as installation of a well, to assure water is provided in the canal to meet habitat requirements. e. A barrier shall be installed between the giant ga rter snake habitat linear open space/buffer area and the adjacent Greenbriar development to ensure that giant garter snakes do not enter the development area, and to prohibit humans and pets from entering the giant garter snake habitat. The design of this barrier shall be subject to USFWS and CDFG review and approval. The entire length of the barrier, which shall be bordered by yards rather than roadways, shall be maintained on the preserve side by a nonprofit land trust to ensure that vegetation or debris does not accumulate near the barrier and provide opportunities for wildlife and pets to climb over the barrier. On the development side, Covenants, Codes and Restrictions (CCRs) shall prohibit accumulation of vegetation or debris adjacent to the barrier. Chain link fencing shall be placed at both ends of the corridor, with locked gates permitting entry only by RD 1000 and NMWD for channel maintenance, and by the preserve manager for habitat monitoring and maintenance purposes. f. Specific requirements associated with the barrier sh all be developed through consultation with USFWS and DFG, and may include the following and/or other specifications that DFG and USFWS consider to be equally or more effective:
► Adequate height and below-ground depth to prevent snakes or burrowing mammals from providing a through-route for snakes by establishing burrows from one side to the other crossing; ► Constructed using extruded concrete or block construction extending a minimum of 36-inches above ground level;
► Maintenance to repair the barrier and to prevent the establishment of vegetation or collection of debris that could provide snakes with a climbing surface allowing them to breech the barrier; ► A cap or lip extending at least two-inches beyond the barrier’s vertical edge to prevent snakes from gaining access along the barrier’s top edge; and
► Signage to discourage humans and their pets from entering the area. g. The Lone Tree Canal linear open space/buffer area sha ll be protected in perpetuity under a conservation easement and managed to sustain the value of this area for giant garter snake habitat connectivity. Compliance and biological effectiveness monitoring shall be performed and annual monitoring reports prepared. This monitoring, reporting, and adaptive management shall be performed as described in Section IV of the NBHCP or following procedures developed in formal consultation with USFWS and DFG and contained in an ESA Incidental Take Permit for the Greenbriar project.
Assessment of Required Width and Other Setback Attributes To date, several recommendations have been made regarding the required width of a setback to conserve canal habitat for giant garter snake use and movement. These previous recommendations include:
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City of Sacramento 3-23 Analysis of Effects on the Natomas Basin HCP ► In the avoidance and minimization measures of a biological opinion for a programmatic consultation with the U.S. Army Corps of Engineers, a measure was included to avoid construction activities within 200 feet from the banks of giant garter snake aquatic habitat (USFWS 1997). The basis given for this distance was that most giant garter snake use of uplands was within 200 feet of aquatic habitat. This same biological opinion also included a requirement that replacement habitat must be located at least 200 feet from roadways “to reduce vehicular mortality” (USFWS 1997).
► The NBHCP includes a requirement (for which there may be exceptions) that reserves be at least 800 feet from existing or planned urban lands, because intensively developed land is “significantly incompatible with the objectives and purposes of the reserve system” and that urban lands are likely to cause significant adverse effects on reserve viability or on covered species occupying the reserve (City of Sacramento et al. 2003, page IV-16). The NBHCP does not include an explanation of why these effects would no longer be significant with urban land at a distance of 800 feet.
► The NBHCP includes a requirement that reserves contain a buffer (typically of natural or ruderal vegetation) 30–75 feet in width to minimize the effects of incompatible land uses. These effects are referred to as “population mortality effects”; the relationship of these effects to the width of the buffer is not described. ► Planning documents for North Natomas have included setbacks ranging from 200 to 250 feet in width between urban development and adjacent agricultural areas (Padre Associates 2005). Initially, these setbacks were intended to reduce conflicts between agriculture and development; later, open space and habitat benefits were added to their purpose.
► The Fisherman’s Lake Buffer Zone Study (Padre Associates 2005) includes a species account for giant garter snake, a review of the USFWS, Natomas Community Plan, and NBHCP setbacks and buffers described above, and a brief evaluation of the effectiveness of the 250- and 800-foot wide buffers that were under consideration at Fisherman’s Lake. This evaluation concludes that “For GGS, all scenarios from the City Boundary and the RD 1000 ROW Boundary alternatives would provide adequate protection of 200 feet from the edge of the channel banks per USFWS guidelines.” Relationships between setback width and particular effects on giant garter snake were not evaluated in this study.
Although the documents with these recommendations did not include analyses to support their recommended setback or buffer widths, our understanding of the ecology of giant garter snake, and of the effects of development on adjacent habitats is sufficient to evaluate the width of habitat required in canal setbacks, the benefits of different buffer widths, and the need for active management and for other measures in setbacks in addition to buffers.
Without a setback that includes sufficient habitat for giant garter snake use and movement, a buffer to prevent adjacent development from degrading this habitat, other measures (such as barriers) incorporated into the setback, and active management of the setback, giant garter snakes might not use and move along Lone Tree Canal.
Determining the required width and constituents of setbacks are subject to several factors. First, increasing land values are a factor in the purchase of the needed setback areas. Second, the level of scientific understanding can adequately determine the need for setbacks, but is generally not adequate for determining the required width for the setbacks (or even a relatively wide range of widths, in many cases) (ELI 2003). In general, wider setbacks reduce adverse effects of adjacent development, but some types of effects diminish only gradually with increased setback width (such as increased predation), and some adverse effects are largely unaltered across a wide range of setback widths (such as the introduction and spread of invasive plants). Consequently, unless setbacks are actively managed and include additional measures (such as barriers) only very wide setbacks (over a thousand feet wide) can preclude most adverse effects.
Although such wide buffers would sustain habitat functions, they are often impracticable, and generally would be a more inefficient use of conservation. Narrower but actively managed setbacks with barriers are also expensive and provide relatively little habitat. They are, however, justified if the conserved habitat is irreplaceable or
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City of Sacramento 3-24 Analysis of Effects on the Natomas Basin HCP otherwise of very high value. Assuming that giant garter snakes would use Lone Tree Canal under the future condition permitted by the NBHCP, and occasionally cross under I-5, Lone Tree Canal provides high value habitat that merits conservation even at a relatively high cost.
Along Lone Tree Canal, the purpose of the setback is to conserve giant garter snake use of, and movement along, the canal to facilitate the occasional movement of individuals through the culverts under I-5. In general, a moderate level of uncertainty exists of the attributes necessary for wildlife use of corridors (ELI 2003). Important factors affecting animal use of a corridor include the corridor’s suitability as habitat, the feasibility of passing through the corridor and the level of effort and of risk involved in doing so. If a corridor does not meet a species’ habitat requirements for residence or foraging, it may not be used for daily or seasonal movement, or for dispersal, and hence would not connect habitat patches (Noss et al. 1996, Rosenberg et al. 1997; Brinson et al. 2002).
Therefore, a setback along Lone Tree Canal should include sufficient habitat to support giant garter snake use of the canal for foraging and residence. This habitat would need to include the canal itself and adjacent uplands.
In general, even species associated with wetlands, streams and waterways may require and regularly use wide zones of adjacent uplands as habitat. For this reason, to provide habitat that meets year-round requirements, setbacks of several hundred feet or more have been recommended for many wetland- and riparian-associated animals (Semlitsch and Bodie 2003).
The width of uplands used by giant garter snakes varies considerably. Giant garter snakes primarily use canals, canal banks, immediately adjacent uplands, and the edges of rice fields. Giant garter snakes generally do not use non-rice agricultural crops (Wylie and Casazza 2000). Many summer basking and refuge areas used by this snake are immediately adjacent to canals and other aquatic habitats, and may even be located in the upper canal banks (Eric Hansen, pers. comm.).
Giant garter snakes, however, also use uplands hundreds of feet from waterways or wetlands. They have been observed hibernating as far as 820 feet from water, and any land within this distance could be important for snake survival in some cases (Hansen 1988). (Hibernaculae [i.e., hibernation sites] this distant from water, however, are most often found in areas with high winter floods.) Giant garter snakes also seek refuge in upland burrows during hot summer weather (Hansen and Brode 1993), and have been documented up to 164 feet from aquatic habitat during this time (Wylie et al. 1997). Use of sites at greater distances from wetlands is associated with landscapes where suitable close sites are not available. This is not generally the case in the agricultural landscape of the Natomas Basin because canal banks often provide refuges and hibernaculae, and the agricultural lands themselves are at slightly lower elevations than canal banks, generally have less cover and fewer refugia than canal banks, and may be flooded or tilled during winter.
The width required to provide cover, forage, refugia, and basking sites along Lone Tree Canal could be quite narrow. Many canals provide cover, foraging habitat, and refugia; and, giant garter snakes regularly use narrow corridors of habitat along canals crossing agricultural landscapes. Although giant garter snake use of, and movement along, a canal might require little more than habitat along the canal and its banks, habitat on adjacent land would likely increase giant garter snake use of, and movement along, a canal.
In addition to habitat, a setback also must contain a sufficient buffer to preclude degradation of canal habitats by human activities. Different types of effects on canal habitats could diminish substantially over short distances, gradually over relatively large distances, or the magnitude of effects could be largely unrelated to setback width.
For example, alteration of local microclimates, drift of herbicides and pesticides applied on adjacent lands, and sediment and pollutants in runoff from adjacent land all typically diminish substantially across a distance of 50– 100 feet (de Snoo and de Wit 1998, Wenger 1999, Forman et al. 2003).
In contrast, the effects of human disturbance diminish gradually with increasing distance. In this context, human disturbance is any human activity that changes the contemporaneous behavior or physiology or one or more animals (Nisbet 2000). Human activities could interrupt the foraging or reproductive activities of animals and
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City of Sacramento 3-25 Analysis of Effects on the Natomas Basin HCP cause them to flee or avoid an area. This may expose these animals to increased risk of mortality, or reduce their reproductive success. In essence, animals perceive humans as potential predators and respond accordingly (Frid and Dill 2002). This perceived predation risk diminishes with distance, but it is affected by other factors. The sensitivity to human disturbance varies among animal species (Cooke 1980, Blumstein et al. 2003), across sites (Blumstein et al. 2003, Rodgers et al. 1997), on trails versus off trails (Miller et al. 2001), with barriers visible to animals (Ikuta and Blumstein 2003) the number of humans (Beale and Monaghan 2004), the type of activity (Holmes et al. 1993, Rodgers and Smith 1995, Rodgers and Smith 1997, Miller et al. 2001), and the visibility of humans to animals (Richardson and Miller 1997, Phillips et al. 2001). Also, to some extent, some animals habituate to human activities (Cooke 1980, Nisbet 2000).
Giant garter snakes are highly sensitive to such human disturbance, and will abandon otherwise suitable habitat as a result of increased human activity such as fishing (Eric Hansen, pers. comm.). Human visits to areas occupied by snakes could result in lowered snake abundance even when the visits are brief in duration and no more than one person, once per day (Eric Hansen, pers. comm.). Human activities can also degrade giant garter snake habitats by trampling vegetation, compacting soils, destabilizing banks, and crushing burrows.
Human use of habitats along Lone Tree Canal would diminish with increasing distance from development.
However, human access from Elkhorn Boulevard, Lone Tree Road, Meister Way, and Street 3 would allow dumping, trampling of vegetation and refugia, and harassment of snakes to occur almost independent of buffer width. This human access would probably reduce giant garter snake use of this section of Lone Tree Canal.
Maintained fences, however, would probably reduce human access to levels that would not reduce snake use of the canal or degrade habitat quality by trampling vegetation and damaging banks.
Similarly, domestic and feral cats and dogs associated with residential development can range widely (hundreds of feet), and harass or prey upon a wide variety of small animals (Crooks and Soule 1999, Hayes et al. 1999, Risbey et al. 2000, Odell and Knight 2001, Lepczyk et al. 2003). Therefore, although it has not been studied, such harassment and predation of giant garter snakes should be considered likely until evidence indicates otherwise. In addition to causing mortality, this predation and harassment could reduce giant garter snake use of the canal. A wide variety of fences have been used to exclude cats and other animals from conserved areas, and many have been found to be effective with regular maintenance (Long and Robley 2004, Moseby and Read 2005).
Some effects are unrelated to buffer width. For example, the effects of road crossings and other structures within setbacks are not mitigated by increasing buffer width. Roads frequently are located across riparian areas, canals, and conserved corridors. These crossings can provide human access across buffers and setbacks, alter physical processes, cause mortality of animals from collisions with vehicles, and create obstacles to animal movement.
At the Greenbriar site, existing culverts on Lone Tree Canal reduce animal movement and the project would also add an additional road crossing at Meister Way and at an additional residential street (Street 3). The canal would not pass under Meister Way through a culvert but rather the roadway would span the canal leaving a 50-foot wide by 7-foot high space for the canal to flow through. At Street 3, the crossing would be 53 feet wide, and although flow under the crossing could be accommodated by two 42-inch culverts, mitigation measure 6.13-1 of the DEIR prohibits placing Lone Tree Canal in culverts at new road crossings (unless it is demonstrated that the culverts would not reduce the potential for giant garter snake movement). Thus, this crossing also would likely be an open span. The effect of these crossings would not be directly related to setback width, but the flow of water through this section of canal, and the enhancement and management of vegetation near the crossings, would likely affect giant garter snake use.
Collisions with vehicles may be an important source of mortality for giant garter snake (Leidy 1992; E. Hansen pers. comm.). Numerous studies have documented mortality of snakes along roads (Rosen and Lowe 1994, Bonnet et al. 1999), negative correlations of reptile or amphibian abundance with road density or traffic levels (Marchand and Litvaitis 2004; Pellet et al. 2004), and the potential for roads to affect population persistence (Marchand and Litvaitis 2004; Gibbs and Shriver 2002). Increasing setback width would not reduce this effect along roads that cross the
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City of Sacramento 3-26 Analysis of Effects on the Natomas Basin HCP setback. Therefore, barriers to prevent snakes from entering roads (and adjacent developed areas) should be incorporated into setbacks. The effectiveness of such barriers has been demonstrated for other species where culverts also exist to allow passage under the road (Guyot and Clobert 1988; Dodd et al. 2005; Aresco 2005).
Buffers can reduce the effects of altered hydrology where they include a considerable portion of the watershed, or where the alteration involves increased overland flow. The effects of water diversions, however, are not reduced by setbacks.
Because of the existence of effects that do not diminish with setback width (or that diminish gradually), additional measures are necessary to buffer canal habitats from adjacent land uses. These additional measures include barriers to human and pet access, visual barriers to shield nearby human activities from sight, provision of supplemental water, and active management of the buffer.
Where barriers are added to buffers, and conserved habitat and buffers are actively managed, the width required for an adequate setback (i.e., conserved habitat plus buffer) can be determined with more precision, because many types of adverse effects can be substantially reduced and some aspects of habitat structure can be maintained by human action.
For giant garter snake setbacks, the buffer must be of sufficient width to include barriers to human and pet access into the buffer, a barrier to prevent snake access to developed areas and roads, and a barrier that shields human activities in developed areas from the vision of snakes. It also should be of sufficient width to include an access road and additional habitat features that are necessary or beneficial for giant garter snake use of the protected corridor.
Because canals, unlike riparian areas, have stable boundaries, the habitat, barrier, and road components of a managed setback can be located in a zone immediately adjacent to the base of the canal bank. The width of this zone would vary primarily with the width desired for incorporating additional habitat components, because the road, fence, and other barrier features would require relatively standard widths.
A setback that consisted of a canal and a buffer of 25–50 feet from the base of each canal bank might be sufficiently wide to include a corridor of canal habitat for giant garter snake use and movement, and an access road and necessary barriers. But, it would not allow additional giant garter snake habitat to be incorporated.
Although giant garter snake uses narrow corridors within agricultural landscapes, additional habitat along canals may be necessary or beneficial in more intensively developed landscapes, particularly if such corridors are lengthy or include impediments to movement, as at the Greenbriar site. In an agricultural landscape, in addition to canal habitat, snakes have access to some cover basking sites, refugia, and foraging habitat on adjacent land, and the presence of these adjacent habitat features could influence snake use of canals. This adjacent habitat also could help protect them from predators, floodwaters, and canal maintenance and other human activities. In particular, because maintenance of vegetation along canals and fluctuations in water levels could temporarily degrade canal habitat along a conserved corridor, additional adjacent habitat may enhance use of the corridor by providing more stable conditions. (This may be important at the Greenbriar site because RD 1000 has an easement for access and maintenance of the Lone Tree Canal.) Wider setbacks would provide the opportunity to incorporate such additional habitat, provide greater flexibility for future management, and would likely result in more effective conservation of conserved corridors along canals. Setbacks with buffers outside of the canal banks that are 100 feet or more in width probably should be sufficient to incorporate habitat components such as channels parallel to the canal and with an adjacent strip of marsh vegetation. To incorporate large water features or wide tracts of managed marsh, buffers would need to be several hundred feet wide. However, creating such extensive habitat immediately adjacent to development may not be desirable. A notable exception might be the inclusion of storm water retention basins; including these structures within canal setbacks may result in wider buffers that more effectively isolate canal habitat from development, while also making more land available for development. It is not known if storm water detention basins and associated structures can be designed to provide suitable habitat for giant garter snake.
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City of Sacramento 3-27 Analysis of Effects on the Natomas Basin HCP In summary, canal habitats actively used by giant garter snake for movement along a canal may be relatively narrow (i.e., less than 50 feet from the canal banks). But, to sustain giant garter snake use of this habitat, a buffer is required to reduce adverse effects from adjacent development and allow additional habitat to be created along the canal as necessary, and to provide some flexibility for future management. To reduce adverse effects, buffers must either be very wide (hundreds to thousands of feet in width), or incorporate barriers to prevent human and pet access and to prevent giant garter snakes from entering developed areas, and must be accessible and actively managed. These components probably add 25–50 feet to the required buffer. Habitat components that may be necessary for giant garter snake use of a canal corridor through a developed landscape probably require at least an additional 50–100 feet, and some types of additional habitat features (e.g., large water bodies) may require a buffer with a width of several hundred feet. Therefore, the total width of setbacks should be at least the width of the canal and its banks, plus an additional 125–200 feet.
The setback proposed by the Greenbriar project is consistent with this width. With the DEIR mitigation it would contain fencing, barrier, habitat enhancement, and management measures, habitat would be enhanced, and the effects of adjacent land uses on this habitat would be minimized. (The specific design of fencing/barriers along Lone Tree Canal, the location of the access road, and the details of habitat enhancement and management measures would be developed in consultation with DFG and USFWS during the development of an HCP for the project.)
OVERALL EFFECT ON CONNECTIVITY OF GIANT GARTER SNAKE HABITATS The DEIR mitigation would likely offset the Greenbriar project’s effects on giant garter snake movement along Lone Tree Canal, and are in addition to, and do not conflict with, the measures incorporated into the MAP HCP. (For example, a smaller setback and a barrier also exist on the Metro Air Park side of Lone Tree Canal.) In addition, because existing conditions do not provide high value habitat for giant garter snake along the entire length of Lone Tree Canal and are not optimal for movement of the snake along the canal, opportunities also exist to enhance connectivity. Management of the canal and adjacent uplands for giant garter snake would result in an improvement over current conditions, and over the future condition resulting from the NBHCP. The project and the mitigation proposed in the DEIR include measures to enhance habitat along the canal (e.g., the creation of marsh habitat along the eastern bank of the canal).
In conclusion, for giant garter snake, significant adverse effects on connectivity between habitats in the southern and central Natomas Basin would be unlikely, and would not cause adverse effects on the implementation of the NBHCP giant garter snake conservation measures.
3.6 CONNECTIVITY OF EXISTING TNBC RESERVES
In the absence of effective avoidance, minimization, and mitigation, the Greenbriar project could adversely affect connectivity of TNBC reserves in the Natomas Basin. As described in the preceding section, in the absence of mitigation measures proposed in the DEIR connectivity of habitats in the southern and central portions of the Natomas Basin could be reduced by the Greenbriar development, and this reduction would be substantial for species that would not pass through the corridor remaining along Lone Tree Canal.
For species not passing through the remaining corridor along Lone Tree Canal, the connectivity of TNBC reserves would be reduced. The travel distances between reserves in the southern and central Natomas Basin, with and without passing through a corridor between the Metro Air Park and the City, indicate this change in reserve connectivity. For example, passing through the Greenbriar site, the distance between the nearest reserve in the southern Basin (the Rosa property) and the nearest reserve in the central Basin (the Tufts property) is about 4 miles across uplands and 4.2 miles along canals (Exhibit 5). If development of the Greenbriar site prevented a species from passing between the Air Park and the City, these distances would become 6.7 and 8.7 miles via uplands and canals, respectively. (These distances assume that an individual that cannot pass between the Air Park and the City also can not pass between the Air Park and the Airport.) Similarly, crossing the Greenbriar site, the shortest distance between
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City of Sacramento 3-28 Analysis of Effects on the Natomas Basin HCP existing reserves in the southern and central Basin (i.e., the Rosa and Ayala properties) is about 3.8 miles across uplands and 5.2 miles along canals. If development of the project prevented movement through a corridor between the Air Park and City, then these distances would increase to 9.4 and 11.2 miles via uplands and canals, respectively.
Though these examples involved the southern reserves closest to the central Natomas Basin, the change in connectivity would be comparable at other reserves in the southern Natomas Basin.
However, as described in the preceding section that addressed effects on habitat connectivity, the Greenbriar project (with the mitigation proposed in the DEIR) would include a set of measures to reduce effects on connectivity; in addition, canal and adjacent upland habitats would be enhanced along Lone Tree Canal.
Therefore, significant adverse effects on the connectivity of existing TNBC reserves would be unlikely.
The project’s proposed off-site reserve lands also could cause some positive effects on connectivity. This would be due primarily to the enhancement of habitat on the Spangler site, which could increase connectivity among the nearby reserves to the east and northwest (the Atkinson/Ruby and Sills reserves, respectively). The preservation of additional land to provide Swainson’s hawk foraging habitat (as required by mitigation measure 6.13-2 of the DEIR) also could increase connectivity of existing TNBC reserves. The location of these lands, however, has not been determined, and thus this potential benefit cannot be described in any detail.
3.7 HABITAT VALUE OF EX ISTING TNBC RESERVES
The Greenbriar project would cause adverse and beneficial effects on the habitat value of existing TNBC reserves.
The adverse effects would result from reducing the acreage of foraging habitat most accessible to (i.e., within 1 mile of) an existing TNBC reserve. The beneficial effects would result from preserving, creating and enhancing habitat adjacent to or near existing TNBC reserves.
3.7.1 E FFECTS OF DEVELOPMENT AT GREENBRIAR SITE
No existing TNBC reserves are within 800 feet of the Greenbriar site and only one reserve (the Rosa property) is within a mile (Exhibit 5). Development at the Greenbriar site would detrimentally affect the quantity and connectivity of foraging habitat for raptors nesting at or near this reserve, and also would similarly affect the Souza and Natomas Farms reserves that are within one and a quarter miles of the site.
The foraging habitat available to raptors nesting at these existing reserves would be detrimentally affected by development at the Greenbriar site. Of the land within a mile of TNBC’s Rosa property, about 31% is in the Metro Air Park or City of Sacramento permit areas; the Greenbriar site accounts for an additional 6%. Thus, habitat value for raptors nesting at this reserve would be reduced under the future condition of the Natomas Basin, and development of the Greenbriar site would further reduce habitat value for raptors. Development of the Greenbriar site also would detrimentally affect the value of TNBC’s Souza and Natomas Farms reserves for nesting raptors, though to a lesser degree than at the Rosa property because these reserves are further from the Greenbriar site (Exhibit 5).
The DEIR requires additional mitigation to offset these effects. For Swainson’s hawk foraging habitat lost, mitigation measure 6.13-2 of the DEIR requires preservation of habitat that provides equal or greater habitat values than the habitat lost at the Greenbriar site. To provide equal or greater foraging habitat values, this mitigation measure would require enhancement and preservation of at least 49 acres of to provide high quality habitat within one mile of an existing TNBC reserve (or of the Swainson’s hawk zone along the Sacramento River). This DEIR mitigation is in addition to the project’s proposed reserves. The habitat provided by this mitigation measure would likely offset the project’s effect on Swainson’s hawks and other raptors residing at or near existing reserves, though the reserves benefiting from habitat enhancements may differ from those adversely affected by the loss of foraging habitat on the Greenbriar site.
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City of Sacramento 3-29 Analysis of Effects on the Natomas Basin HCP Though it is possible that the project could detrimentally affect foraging habitat available to giant garter snakes at the Rosa, Souza and Natomas Farms reserves, this effect was considered insignificant. Because canals connect these reserves to habitat suitable for giant garter snake on the Greenbriar site, and because the site is within 1–2 miles of these reserves (Exhibit 5), development of the Greenbriar site could reduce the quantity of suitable habitat available to giant garter snakes foraging or residing at these reserves. While not discountable, this effect may be negligible because the culvert at Interstate 5 may restrict snake movement along the canal such that snakes residing south of Interstate 5 rarely forage north of Interstate 5. Furthermore, loss of habitat within 1–2 miles of these reserves would be partially, or perhaps even fully, offset by the creation of 14 acres of marsh habitat at the Natomas 130 parcel that is also connected to these reserves by canals, and is at a distance from the reserves comparable to that of the Greenbriar site.
3.7.2 E FFECTS OF PROPOSED RESERVES
The restoration of marsh at the proposed reserves would cause both adverse and beneficial effects on the habitat value of existing reserves. The acreage of Swainson’s hawk foraging habitat would be reduced at the Natomas 130 parcel. Restoration at this proposed reserve would reduce the acreage of Swainson’s hawk habitat because 14 acres of fallow agricultural land (which was non-rice crop in 2001) would be converted to marsh, which would provide only smaller areas of moderate quality foraging habitat, while only 14 acres would be enhanced for Swainson’s hawk foraging on the remainder of the site. However, the enhanced foraging habitat would be of high quality which would provide resources sufficient to offset the lost habitat acreage.
The proposed reserves could increase habitat available to giant garter snakes at existing TNBC reserves in the Central Basin (i.e., the Tufts, Sills, Ruby, and Atkinson reserves) because one of these reserves (the Spangler property) could be accessible to snakes using those reserves. These existing reserves are all within two miles of the proposed Spangler reserve where marsh would be created and rice will be managed to enhance its habitat value for giant garter snake (Exhibit 5).
The project’s proposed reserves would contribute to the size and connectivity of existing TNBC reserves. The North Natomas 130 parcel is immediately north of the TNBC Cummings reserve (Exhibit 5) and would increase the size of that reserve; the Spangler parcel is located between the Tufts and Atkinson reserves and is also connected to them via canals and drains (Exhibit 5); thus, it would increase their connectivity. The preservation of additional land to provide Swainson’s hawk foraging habitat (as required by mitigation measure 6.13-2 of the DEIR) also could increase connectivity of existing TNBC reserves. By increasing the size and connectivity of existing reserves, and by increasing the area of preserved land in the vicinity of existing reserves, the project would beneficially affect the habitat value of existing reserves.
3.7.3 O VERALL EFFECT ON HABITAT VALUE OF TNBC RESERVES Overall, the Greenbriar project would not adversely affect the habitat quality of the existing TNBC reserve system, and could cause a beneficial effect by preserving, creating, and enhancing habitat on adjacent or nearby lands that would benefit wildlife residing at or using existing TNBC reserves. However, it could cause small adverse effects on the foraging habitat available to Swainson’s hawks nesting at or near reserves in the southern Natomas Basin, and though its mitigation would provide foraging habitat for hawks nesting at TNBC reserves, these may not be the same reserves that would experience a loss of foraging habitat. Thus, individual reserves may experience small adverse or beneficial effects due to the Greenbriar project.
3.8 WATER AVAILABILI TY AT TNBC RESERVES
The Greenbriar project would eliminate several canals on the Greenbriar site, and would convert this site from predominantly agricultural to urban land cover. These changes, however, would not be anticipated to alter water availability to TNBC reserves or cause additional canals to be eliminated outside of the Greenbriar site (Dave Fischer, Natomas Central Mutual Water Company, pers. comm.).
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City of Sacramento 3-30 Analysis of Effects on the Natomas Basin HCP The project would alter drainage of the Greenbriar site, and eliminate delivery of irrigation water by canals. These changes would affect water levels in canals and drains connected to the site. Because no TNBC reserves are adjacent to the Greenbriar site, these alterations are not anticipated to alter water availability at TNBC reserves.
The additional reserve lands associated with the Greenbriar project are in the Natomas Basin and thus would increase the portion of the Natomas Central Mutual Water Company held by shareholders concerned with the habitat values of the canal system and with the availability of water at TNBC reserves. In fact, TNBC has already requested changes to operations and maintenance practices (J. Roberts, pers. comm.). In the future, this may contribute to attainment of NBHCP goals and objectives, but is not anticipated to alter any specific operations by the water company in the near future.
3.9 OPPORTUNITIES TO ESTABLISH ADDITIONAL TNBC RESERVES The Greenbriar project would cause both beneficial and adverse effects on opportunities to establish additional TNBC reserves. The adverse effects would result from reducing the acreage of land available to provide the mitigation required by the NBHCP. The beneficial effects would result from increasing the total acreage of reserves in the Natomas Basin, and thus increasing opportunities to establish larger reserves.
3.9.1 E FFECTS ON AVAILABILITY OF LAND FOR NBHCP RESERVE ESTABLISHMENT Mitigation for the NBHCP consists of 8,750 acres of managed marsh, rice, and uplands. Based on the acreage of the Metro Air Park, City of Sacramento, and Sutter County permit areas for urban development, and of existing development outside of those areas, the Natomas Basin contains substantially more than 8,750 acres of land potentially suitable as and potentially available for mitigation. Of the Natomas Basin’s 53,537 acres, about 26,376 are outside of permit areas and in land cover types suitable for preservation. However, at least 5,205 acres of these lands are unavailable for preservation as NBHCP mitigation (e.g., lands in suitable land cover that are owned by the Sacramento International Airport). Thus, there are about 21,171 acres of land that are both potentially suitable as mitigation and potentially available.
Although the acreage of potentially suitable and available land could be over twice the acreage required by the NBHCP for preservation, the NBHCP, nonetheless, requires that a substantial portion of suitable land in the Natomas Basin be preserved. Thus, numerous factors affecting the suitability of land for preservation could complicate establishment of an interconnected reserve system of this size, and may increase its cost or compromise the habitat quality of reserves. These factors include existing easements, infrastructure and buildings, availability of land for purchase, adjacent land uses and proximity to urban development, connectivity to other reserves, availability of water, suitability of soils for the establishment of managed marsh, and parcel size relative to the desired size of reserves.
The Greenbriar project would reduce the acreage available for preservation as mitigation for development permitted by the NBHCP and affect the feasibility of preserving land adjacent to the Greenbriar, proposed reserve and mitigation sites. Because of the Greenbriar project, 815 acres would become unavailable or unsuitable for preservation. These lands include: 546 acres developed at the Greenbriar site, 265.8 acres at the proposed Natomas 130 and Spangler reserves, 30.6 acres at the proposed reserve along Lone Tree Canal, and at least 49 acres of Swainson’s hawk foraging habitat required by mitigation measure 6.13-2 of the DEIR at mitigation site(s) still to be determined. Of this land, 76 acres are already in land cover types that are unsuitable for preservation and subsequent restoration or enhancement (e.g., rural residential land). Thus, overall, the Greenbriar project reduces the acreage of land potentially suitable and available for preservation by 815 acres, from 21,171 to 20,356 acres, a reduction of about 4%. Even with this reduction, the remaining acreage of land potentially suitable and available for preservation (20,356 acres) would be more than twice the 8,750 acres the NBHCP requires for the reserve system.
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City of Sacramento 3-31 Analysis of Effects on the Natomas Basin HCP
3.9.2 E FFECTS OF GREENBRIAR SITE DEVELOPMENT ON TNBC RESERVE
ESTABLISHMENT
Though the NBHCP did not identify the Greenbriar site as a potential reserve, the NBHCP also did not identify a complete set of potential reserve sites; therefore, most land outside of areas permitted for urban development, including the Greenbriar site, could be considered a potential reserve site. Development of the Greenbriar site would reduce options for establishing a reserve over 400 acres in size that included parcels adjacent to the Greenbriar site, and would eliminate any opportunity for a reserve that included the Greenbriar site.
Consequently, this eliminates the option of preserving the entire corridor between the Metro Air Park and Sacramento City permit areas.
The Greenbriar site has, or could be enhanced to provide, conservation values that would merit preservation, but it also has several major limitations on the habitat values that it could provide. Much of the Greenbriar site provides habitat for covered species, and the site could be managed to provide various combinations of marsh, rice, upland, and canal habitats. It also occupies a corridor between the southern and central Natomas Basin that is important for the movement and dispersal of individuals, particularly for giant garter snake. A portion of the site, however, is in land cover types that are unsuitable for preservation and subsequent restoration or enhancement (e.g., rural residential land). Other portions of the site are immediately adjacent to major highways, or under the future condition of the Basin would be adjacent to urban development, and these areas would potentially experience high levels of human-wildlife conflicts. Nearly half of the site is either unsuitable for preservation and restoration or would be within 800 feet of a major highway or urban development. Highways and urban development would also reduce the connectivity of habitats on the Greenbriar site with habitats that would remain to the north and to the south. Despite these limitations, preserving the Greenbriar site could contribute more to sustaining the viability of the Basin’s giant garter snake population and to attaining the goals and objectives of the NBHCP than would many other sites, because the Greenbriar site provides the opportunity to preserve and enhance the connectivity of canal habitats between the southern and central Natomas Basin.
Though it would develop most of the site, the project would preserve the most important portion of the site for giant garter snake and for connectivity between the southern and central Natomas Basin. It would preserve 30.6 acres immediately adjacent to Lone Tree Canal that would establish a 250-foot wide conserved corridor. This reserve would include barriers to reduce effects of adjacent development, measures to assure water flow, restoration and enhancement of habitat, and funding for TNBC to actively manage the site. Thus, the project would contribute to the conservation of a narrow, but ecologically important, corridor along this canal adjacent to the Metro Air Park.
3.9.3 E FFECTS OF PROPOSED RESERVES ON NBHCP RESERVE ESTABLISHMENT The Greenbriar project’s reserves also could contribute to the size and connectivity of future reserves. By preserving additional land adjacent to TNBC reserves, the project creates additional opportunities to create reserves of a given size and to create larger reserves (which would tend to have greater habitat values per acre than smaller reserves). For example, the Spangler reserve potentially could be joined to the Tufts reserve through future land acquisitions, as it would be only about a quarter-mile from the Tufts reserve (Exhibit 6); in this case, preservation of the intervening parcel would result in a larger reserve than would have resulted without the Greenbriar project’s preservation of the Spangler property.
Overall, the Greenbriar project would not substantially reduce opportunities for establishing additional reserves for the NBHCP because sufficient suitable land is available to provide reserves both for the NBHCP and for the Greenbriar project, the project would preserve the most ecologically important portion of the Greenbriar site, and the project’s reserves would increase opportunities to establish larger reserves.
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City of Sacramento 3-32 Analysis of Effects on the Natomas Basin HCP
Source: Wildlands 2005
Location of TNBC Reserves Exhibit 6
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City of Sacramento 4-1 Analysis of Effects on the Natomas Basin HCP 4 POTENTIAL EFFECTS OF THE GREENBRIAR PROJECT ON
COVERED SPECIES
4.1 GIANT GARTER SNAKE
4.1.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
Giant garter snakes (Thamnophis gigas) typically inhabit sloughs, marshes, and drainage canals characterized by slow flowing or standing water, permanent summer water, mud bottoms, earthen banks, and an abundance of preferred forage species.
During their active season (May through October), mature giant garter snakes typically spend the majority of their time in canals and sloughs (Wylie and Casazza 2000). During late spring and summer, rice fields also provide foraging habitat for this species (Brode and Hansen 1992). Use of rice, however, is concentrated around the perimeter of the fields (Wylie and Casazza 2000; E. Hansen, pers. comm.). (Rice may, however, be an important source of prey and may export prey with drain waters into connected canals.) Giant garter snakes avoid areas of dense riparian overstory, and use burrows, crevices, undercut banks and large rocks to hide from predators.
Winter hibernaculae include small burrows and soil crevices above prevailing flood elevations; these are typically located near aquatic habitat and in grassland or ruderal vegetation. (In the Natomas Basin, most canal banks have small burrows and crevices, and thus the banks of canals that are dewatered in winter can provide hibernaculae.) Managed marsh also provides habitat for giant garter snake. In contrast to rice, managed marsh provides habitat year-round, and habitat elements (such as dense cover, basking sites, and refugia) to meet all of the giant garter snakes daily and seasonal needs. Managed marshes in the Natomas Basin have been designed to provide these habitat elements throughout the marsh, as opposed to the limited availability of the same elements in rice, which contributes to the use of rice primarily around the perimeter of rice fields.
The USFWS (1997) has determined that essential habitat components consist of the following:
► Adequate water during the snake’s active period (early spring through mid-fall) to provide a prey base and cover;
► Emergent, herbaceous wetland vegetation, such as cattail and bulrushes, for escape cover and foraging habitat;
► Upland habitat for basking, cover, and retreat sites; and ► Higher elevation uplands for cover and refuge from flood waters.
Land cover types designated as giant garter snake habitat in the NBHCP include canals, ponds and seasonally wet areas and rice. Managed marsh also provides habitat. Small fish are the primary prey of this species; they will also take amphibians when available.
Home Range Size and Movement
Based on radio-telemetry studies by Wylie and Casazza (2000), the size of giant garter snake home ranges were between 32 and 215 acres (median = 86 acres) at Elverta and Fisherman’s Lake sites. For comparison, home
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City of Sacramento 4-2 Analysis of Effects on the Natomas Basin HCP ranges were between 5 and 213 acres (median = 39.5 acres) at Gilsizer Slough in Sutter County, and 22 and 2,070 acres (median = 128 acres) at the Colusa National Wildlife Refuge. Most giant garter snake activity within these home ranges is concentrated along canals, sloughs, and the edge of aquatic habitats (Wylie and Casazza 2000; Wylie et al. 2000; Wylie et al. 2003).
Giant garter snakes rely on canals and ditches as movement corridors. These corridors provide important habitat, are used during daily movements within a home range, and are necessary for giant garter snake dispersal and the resulting exchange of individuals and alleles between subpopulations. Unvegetated canals may be used as dispersal corridors, but snakes typically do not remain in exposed canals because of increased vulnerability to predators. Giant garter snakes have been reported traveling over one mile, and may move as much as two miles in a day (Hansen and Brode 1992).
The USFWS has previously considered 200 feet as the width of upland vegetation providing habitat along the borders of aquatic habitat for giant garter snake (USFWS 1997). However, the width of uplands used by giant garter snakes varies considerably. Many summer basking and refuge areas used by this snake are immediately adjacent to canals and other aquatic habitats, and may even be located in the upper canal banks (Eric Hansen, pers. comm.). Giant garter snakes have also been observed hibernating as far as 820 feet (250 m) from water, however, and any land within this distance may be important for snake survival in some cases (Hansen 1988). (Hibernaculae this distant from water, however, are most often found in areas with high winter floods.) Giant garter snakes also seek refuge in upland burrows during hot summer weather (Hansen and Brode 1993), and have been documented up to 164 feet from aquatic habitat during this time (Wylie et al. 1997).
Mechanisms of Habitat Degradation
Increased Predation
Known predators of giant garter snake include raccoons, skunks, opossums, foxes, hawks, egrets, herons, and bitterns (USFWS 1999a). All of the mammalian predators in this list increase in proximity to residential areas as a result of supplemental food sources and reduced coyote abundance (Crooks and Soule 1999). Domestic dogs may also prey on giant garter snakes, and cats may prey on juveniles. Although predation of giant garter snake by cats and dogs has not been studied scientifically, the effects of cats and dogs on small animals has been documented in a variety of ecosystems, and based on current understanding, cat and dog predation on giant garter snake is highly likely.
Disturbance from Human Activity
Giant garter snakes are highly sensitive to human disturbance, and will abandon otherwise suitable habitat as a result of increased human activity such as fishing (Eric Hansen, pers. comm.). Human visits to areas occupied by snakes may result in lowered snake abundance even when the visits are brief in duration and no more than one person, once per day (Eric Hansen, pers. comm.). Human activities can also degrade giant garter snake habitats by trampling vegetation, compacting soils, destabilizing banks, and crushing burrows, and can cause vehicle collisions with snakes.
Habitat Fragmentation
In a dynamic habitat such as the Natomas Basin, giant garter snakes frequently move in response to changing conditions in their rice, marsh, canal, and ditch habitats, especially during the dry summer months (Wylie and Casazza 2000). Connectivity between these areas is thus extremely important for snake survival and reproduction, as well as the genetic interchange and patch-recolonization ability necessary for the viability of the overall Basin population. Any loss or degradation of snake movement corridors may thus cause effects that far outreach the area of the directly impacted corridors.
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City of Sacramento 4-3 Analysis of Effects on the Natomas Basin HCP Operation and Maintenance of Waterways
Water channels lose their habitat value for giant garter snakes when cleaned of aquatic vegetation, during low/no flow periods or when high water releases eliminate or alter basking sites, refugia, foraging areas or juvenile microhabitat (USFWS 1999a). In the Natomas Basin, canal and drain maintenance, and irrigation practices, involve periodic clearing of vegetation along waterways, and short-term, seasonal and inter-annual changes in flow in waterways. A recent habitat assessment of canals and drains throughout the Natomas Basin indicates that operation and management practices are reducing habitat quality along a substantial portion of these waterways (Jones & Stokes 2005). Water diversions may also reduce the abundance of the snakes’ aquatic prey. Water diversions or changes in land use within the area served by a canal or drain watershed may alter flows or even cause a canal or drain to be abandoned.
Water Quality
Aquatic communities may be greatly affected by surrounding land use. Urban areas can exert different and in some cases stronger effects than agricultural lands (Bury 1972, Moore and Palmer 2005). Residential developments typically result in increased runoff of hydrocarbons and of chemicals used for lawns and gardens, and increased stormwater volume (and associated increases in flow depths and velocities) because of high coverage of impervious surfaces.
DISTRIBUTION
Information on CNDDB Occurrences
The 2002 CNDDB records cited in the NBHCP listed 168 giant garter snake occurrences in California, 38 of which occurred in the Natomas Basin. As of 2005, there are 171 known occurrences in California, of which 170 are considered extant. At this time, CNDDB lists 42 occurrences in the Natomas Basin, of which 42 are considered extant.
Other Information on Distribution and Abundance in Natomas Basin A USGS-BRD study conducted from 1998 to 1999 recorded 277 individual giant garter snakes in the Natomas Basin (Wylie and Casazza 2000). Surveys conducted in 2004 for the Natomas Basin Conservancy recorded 152 snake observations, at least 86 of which were verified individuals (Natomas Basin Conservancy 2004). At the western edge of the Greenbriar site, sampling conducted during 1998 and 1999 detected at least five giant garter snakes in Lone Tree Canal; based on these results, giant garter snake population density for the canal was estimated at 2.4 snakes per 1,000 feet of canal length (95% confidence interval = 2–3.7) (Wylie et al. 2000). The density of snakes recorded at the Greenbriar site and elsewhere along canals and in rice lands of the Natomas Basin has a couple of important implications for this analysis. First, any alteration of even an acre of these land cover types is likely to affect at least one giant garter snake. Second, canals can provide moderate or high quality habitat, and thus arguments based on the premise that canals in general provide marginal habitat may be inaccurate.
Monitoring data collected in 2004 for The Natomas Basin Conservancy (Jones & Stokes 2005) recorded smaller snake sizes on average (corresponding to younger snakes with lower reproductive outputs) than in previous years.
When combined with data from previous years, this suggests a declining trend in snake size, which would correspond to an on-going decline in population viability unless coupled with a rapidly increasing population size (which is not indicated by the monitoring data). However, changes in sampling techniques and sampling locations make the interpretation of these data problematic.
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City of Sacramento 4-4 Analysis of Effects on the Natomas Basin HCP
4.1.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
Changes in habitat acreages are summarized in Table 4-1. At the Greenbriar site, there would be a loss of an estimated 172 acres of GGS habitat from conditions at the time of the NBHCP (2001). At the proposed reserves, approximately 45 acres of snake habitat would be converted to non-habitat and 14 acres of snake habitat would be created from non-habitat. Thus, the project as a whole would yield a net loss of 204 acres of snake habitat.
Table 4-1
Change in Acreage of Giant Garter Snake Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total
Change
Future Condition
with Project
Canals 1,162 -15.0 0.0 -1.4 -16.4 1,146
Ponds & seasonally wet areas 2,259 2.7 14.2 184 200.9 2,460 Rice 11,643 -160.0 - -228 -388 11,255
Total 15,064 -172.4 14.2 -45.4 -203.5 14,860
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
Effects on Quality of Habitat
Areas Adjacent to Developed Land or Highways
As discussed above in Mechanisms of Habitat Degradation, without mitigation, snakes traveling through the Lone Tree Canal or using other canal and rice habitats near the proposed development would likely be adversely affected by the project’s residential development through increased predation, disturbance, and degradation of aquatic habitat. (The adjacent Metro Air Park development does not include residential development.) Development of the Greenbriar site also would reduce the acreage of land draining into Lone Tree Canal, and thus would likely lead to reduced flows in the canal. In the absence of measures to offset these alterations, the quality of giant garter snake habitat along Lone Tree Canal would likely be reduced.
The project does, however, include measures to reduce these effects, and the DEIR mitigation includes additional measures. These measures are described in the following section (Effects on Connectivity).
The project also could create conflicts with continued cultivation of rice on the property north of the Greenbriar site. Aerial application of pesticide and herbicide probably is not feasible immediately adjacent to residential development (C. Aubry, pers. comm.), which could affect the viability of rice cultivation on the adjacent parcel.
This issue is discussed further under Habitat Quality in the Natomas Basin in Chapter 3 of this report.
Alteration of Habitat Quality at Proposed Reserve Sites At the proposed Spangler and Natomas 130 reserves, in addition to the 14 acres of marsh habitat creation (from non-habitat), 190 acres of giant garter snake habitat would be enhanced by creating marsh from rice (i.e., 184 acres of marsh and 6 acres of associated canals). This change in land cover and management should considerably increase habitat quality for giant garter snake, because marsh provides higher quality habitat for giant garter snake than rice. The reasons that marsh provides higher quality habitat than rice include:
Greenbriar Development Project EDAW
City of Sacramento 4-5 Analysis of Effects on the Natomas Basin HCP ► Giant garter snakes use the full extent of managed marshes, whereas they primarily use the margins of rice fields;
► Marshes provide habitat throughout the active period of the snake, whereas rice fields do not provide habitat during early and mid-spring, and are typically drained before the end of the snake’s active period; and ► Marsh provides habitat in all years, whereas rice is fallowed periodically.
Though some uncertainty exists regarding the magnitude of benefits resulting from these enhancements, it is likely that they offset the habitat values that would be lost by development at the Greenbriar site. The preservation and management of this 204 acres of habitat for giant garter snake also provides benefits (such as reduced human disturbance) in addition to the benefits resulting from the conversion of rice to managed marsh.
Effects on Connectivity
The Greenbriar project’s potential effects on connectivity of giant garter snake habitat are described in detail in Section 3.5 Connectivity of Habitat in the Natomas Basin.
Effects of Construction-Related Activities
During the construction at the Greenbriar and proposed reserve sites, giant garter snakes could be killed or injured by vehicle strikes (Leidy 1992), crushed beneath heavy machinery, entombed in or excavated from their winter retreats (Wylie and Casazza 2000). The Greenbriar DEIR and Natomas Basin HCP include measures to avoid and minimize direct loss of giant garter snakes through construction. For the Greenbriar project, these measures include:
a. To ensure that the project does not diminish habitat connectivity for giant garter snake between the southwest and northwest zones identified in the NBHCP, approximately 30.6 acres along Lone Tree Canal shall be protected and managed as giant garter snake habitat. This on-site habitat preservation shall protect an approximately 250-foot wide corridor of giant garter snake habitat that includes the canal and approximately 200 feet of adjacent uplands. Uplands within the linear open space/buffer area shall be managed as perennial grassland as described below. Additional aquatic habitat for giant garter snake shall be created along the east bank of Lone Tree Canal by construction and maintenance of a 2.7 acre tule bench. The habitat shall be managed in perpetuity as high-quality habitat for giant garter snake. Compliance and biological effectiveness monitoring shall be performed and annual monitoring reports prepared within six months of completion of monitoring for any given year. This monitoring, reporting, and adaptive management shall be performed as described in Section IV of the NBHCP.
b. To ensure that the project does not diminish gian t garter snake movement along Lone Tree Canal, all new road crossings of Lone Tree Canal shall be designed to minimize obstacles to giant garter snake movement.
The use of culverts under new road crossings on Lone Tree Canal shall be prohibited unless it can be demonstrated that the culverts will not diminish the potential for giant garter snake movement through the section of Lone Tree Canal protected by the setback fence and conservation easement. . c. Upland giant garter snake habitat within the Lone Tree Canal linear open space/buffer area shall be created and managed to provide cover, basking areas, and refugia during the winter dormant period. Hibernaculae would be constructed at regular intervals by embedding concrete or coarse rock in the bank or in a berm along the Lone Tree Canal corridor to provide additional winter refugia. Upland habitat with the linear open space/buffer areas shall be converted to native perennial grassland and managed, in perpetuity, as perennial grassland habitat.
d. Aquatic habitat shall be maintain ed throughout the giant garter snake active season in Lone Tree Canal, in perpetuity. This is the legal responsibility and obligation of Metro Air Park property owners (MAP). The
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City of Sacramento 4-6 Analysis of Effects on the Natomas Basin HCP MAP HCP includes provisions for maintaining water in the canal such that the basic habitat requirements of the giant garter snake are met. The MAP HCP also provides a road map, through “Changed Circumstances”, to address procedures to follow if water is not being maintained in the canal to meet these requirements. As described in the MAP HCP, the MAP is legally obligated to assure these requirements are met, and financial and procedural mechanisms are included in the MAP HCP to enforce this. It is, therefore, assumed that MAP will provide water to Lone Tree Canal, as required by the MAP HCP and ITP, in perpetuity. It is also assumed that USFWS will use all reasonable means available to it, to enforce this MAP HCP requirement. If water is not provided to Lone Tree Canal by the MAP to meet the habitat requirements of giant garter snake, as required by the MAP HCP, and USFWS exhausts its enforcement responsibilities, the project applicant shall assume the responsibility of providing suitable giant garter snake aquatic habitat throughout the section of Lone Tree Canal protected by the fence and conservation easement. However, as stated herein, the project applicant shall only assume this responsibility if it has been sufficiently demonstrated to the City that USFWS has exhausted all reasonable means to compel MAP to comply with the relevant conditions of the MAP ITP.
Specific requirements related to ensuring suitable aquatic habitat in Lone Tree Canal is present, in perpetuity, throughout the giant garter snake active season shall be developed through consultation with DFG and USFWS, and included in the new or amended HCP for Greenbriar, and may include mechanisms, such as installation of a well, to assure water is provided in the canal to meet habitat requirements. e. A barrier shall be installed between the giant ga rter snake habitat linear open space/buffer area and the adjacent Greenbriar development to ensure that giant garter snakes do not enter the development area, and to prohibit humans and pets from entering the giant garter snake habitat. The design of this barrier shall be subject to USFWS and CDFG review and approval. The entire length of the barrier, which shall be bordered by yards rather than roadways, shall be maintained on the preserve side by a nonprofit land trust to ensure that vegetation or debris does not accumulate near the barrier and provide opportunities for wildlife and pets to climb over the barrier. On the development side, Covenants, Codes and Restrictions (CCRs) shall prohibit accumulation of vegetation or debris adjacent to the barrier. Chain link fencing shall be placed at both ends of the corridor, with locked gates permitting entry only by RD 1000 and NMWD for channel maintenance, and by the preserve manager for habitat monitoring and maintenance purposes. f. Specific requirements associated with the barrier sh all be developed through consultation with USFWS and DFG, and may include the following and/or other specifications that DFG and USFWS consider to be equally or more effective:
► Adequate height and below-ground depth to prevent snakes or burrowing mammals from providing a through-route for snakes by establishing burrows from one side to the other crossing; ► Constructed using extruded concrete or block construction extending a minimum of 36-inches above ground level;
► Maintenance to repair the barrier and to prevent the establishment of vegetation or collection of debris that could provide snakes with a climbing surface allowing them to breech the barrier; ► A cap or lip extending at least two-inches beyond the barrier’s vertical edge to prevent snakes from gaining access along the barrier’s top edge; and
► Signage to discourage humans and their pets from entering the area. g. The Lone Tree Canal linear open space/buffer area sha ll be protected in perpetuity under a conservation easement and managed to sustain the value of this area for giant garter snake habitat connectivity. Compliance and biological effectiveness monitoring shall be performed and annual monitoring reports prepared. This monitoring, reporting, and adaptive management shall be performed as described in Section IV of the NBHCP or following procedures developed in formal consultation with USFWS and DFG and contained in an ESA Incidental Take Permit for the Greenbriar project.
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City of Sacramento 4-7 Analysis of Effects on the Natomas Basin HCP In combination, these measures would minimize injury and mortality to giant garter snakes as a direct result of construction-related activities.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
As discussed above in Mechanisms of Habitat Degradation, without mitigation, giant garter snakes would likely experience increased predation near the proposed residential development because of the increased abundance of domestic dogs and cats, as well as human-associated raccoons, skunks and opossums. Domestic cats have been recorded between 98–590 feet from homes, unattended domestic dogs between 590–1,083 feet from homes (Odell and Knight 2001), and increased abundance of native predators may extend farther. As this distance is well beyond the proposed 250-foot wide corridor between the proposed residential development and the Lone Tree Canal, the project would likely result in increased predation of snakes using the canal. The increased human population in the area would also increase the potential for human activity near the canal, which may lead to site avoidance or abandonment by snakes (Eric Hansen, pers. comm.). Increased human activity along the canal could result in increased canal maintenance including further clearing of vegetation. Snake mortality because of vehicle strikes (Leidy 1992) may also increase on existing roads because of the increased traffic associated with the project.
The project does, however, include measures to reduce these effects, and the DEIR mitigation includes additional measures. These measures are described in the preceding section (Effects on Connectivity).
OVERALL EFFECT ON POPULATION VIABILITY
The project would cause both adverse and beneficial effects on the giant garter snake population of the Natomas Basin. Beneficial effects would include preserving, creating, and enhancing habitat at the reserve sites, preserving a corridor along Lone Tree Canal, and contributing to the connectivity of habitat and existing TNBC reserves adjacent to or near the proposed reserves. Adverse effects would include a reduction in the total acreage of habitat, and possibly degradation of habitat near the Greenbriar site and reduced connectivity along Lone Tree Canal due to increased human disturbance and predation. The DEIR mitigation, however, would reduce adverse effects and ensure that connectivity of giant garter snake habitat was conserved along Lone Tree Canal.
Overall, the project would not adversely affect giant garter snake, and its overall effect on population viability could be beneficial. The loss of habitat acreage would probably be offset by the increased habitat quality resulting from the preservation of habitat, and conversion of rice to marsh.
The proposed creation of 14 acres of marsh from non-rice crops, conversion of 184 acres of rice to marsh, and preservation of an additional 6.2 acres along associated canals would likely offset the loss of 388 acres of rice and 16 acres of canal habitat. The basis of this interpretation is the greater habitat value of managed marsh relative to rice and the general benefits of habitat preservation.
Managed marsh provides substantially greater habitat values for giant garter snakes than rice for several reasons.
These reasons include:
► Giant garter snakes primarily use the margins of rice fields, whereas they use the full extent of managed marshes. These marshes are designed to provide open water, foraging habitat, dense cover, basking sites, and refugia in close proximity throughout the marsh. (For example, an acre of managed marsh provides several times the edge habitat than does a rice field.)
► Marshes provide habitat throughout the active period of the snake. Rice fields do not provide habitat during early and mid-spring, and are typically drained before the end of the snake’s active period. Thus, for a portion of their active period, giant garter snakes must rely entirely on non-rice habitats. In the Natomas Basin, these habitats are canals and managed marsh. In contrast, managed marshes provide habitat year-round.
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City of Sacramento 4-8 Analysis of Effects on the Natomas Basin HCP ► Rice is fallowed periodically, and thus does not provide habitat in all years; in contrast, a managed marsh does provide habitat in all years.
Preservation of habitat has benefits in addition to those of habitat enhancement. In the Natomas Basin, a particularly important benefit of habitat preservation is that it ensures that the habitat will continue to exist, and it buffers total habitat availability from year to year fluctuations. For giant garter snake, privately owned habitat in the Natomas Basin is primarily rice and associated canals, and there are no assurances that rice cultivation will continue on any particular site. Furthermore, agricultural markets will cause the total acreage of rice, and consequently of giant garter snake habitat, to fluctuate substantially from year to year. Such environmental fluctuations strongly influence populations and reduce their viability. In contrast, preserved lands will provide habitat on a much more consistent basis, and thus reduce the magnitude of fluctuations in habitat availability.
Both habitat enhancement and preservation also can contribute to population viability by reducing anthropogenic causes of mortality. Preservation reduces human disturbance, and minimizes activities that could harm or kill snakes. Habitat enhancement also reduces or eliminates agricultural activities that can harm or kill snakes. In addition, the preservation and enhancement of habitat typically results in larger blocks of higher quality habitat, and this should reduce long distance movements by snakes, which would also reduce the risk of mortality associated with those movements. (Dispersal and other long distance movements are dangerous for snakes, particularly where road crossings are involved [Bonnet et al. 1999, Rosen and Lowe 1994].) For these reasons, an acre of managed marsh may provide habitat values comparable to or substantially greater than two acres of rice. The project would reduce rice acreage by 388 acres (and canal acreage by 16 acres) and would increase the acreage of preserved, managed marsh by 201 acres. Thus, it is likely that the project would not reduce habitat values for giant garter snake, and thus would not reduce the viability of the giant garter snake population due to a reduction in habitat values.
The project is also unlikely to reduce the viability of the giant garter snake population due to adverse effects on connectivity. The project (with the DEIR mitigation) would conserve connectivity and habitat for giant garter snake along Lone Tree Canal, which is an important waterway connecting the southern and central Natomas Basin, and proposed reserves would contribute to connectivity of habitats and reserves in the southern and central Basin.
4.2 NORTHWESTERN POND TURTLE
4.2.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
Northwestern pond turtles (Clemmys marmorata marmorata) are most commonly found in permanent or nearly permanent wetlands, ponds, slow-moving streams and irrigation ditches (Zeiner et al. 1988). Adjacent upland areas are also used for basking and egg-laying. Land cover types designated as pond turtle habitat in the NBHCP include canals, ponds and seasonally wet areas, rice and riparian. Special habitat features that improve turtle abundance, survival and reproductive success are rocks, logs, open mud banks, emergent aquatic vegetation and streamside vegetation. These features provide the turtles with basking sites and cover from predators (Stebbins 1972). Although pond turtles feed primarily on aquatic invertebrates (USFWS 1992), they also feed on plants, small fish and carrion.
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City of Sacramento 4-9 Analysis of Effects on the Natomas Basin HCP Home Range Size and Movement
Upland areas adjacent to aquatic habitat are essential for reproduction, and eggs may be laid as far as 1,319 feet (0.25 mi) from water (Hays et al. 1999). Hatchling and adult turtles may winter in upland sites, and turtles may move more than one mile overland in response to desiccation of local water bodies or other forms of habitat loss or degradation.
Mechanisms of Habitat Degradation
Increased Predation
Hayes et al. (1999) documented predation on pond turtles by domestic dogs; unattended dogs have been recorded between 590–1,083 feet (180–330 m) from homes (Odell and Knight 2001). These distances indicate the project would likely result in increased predation of any pond turtles using Lone Tree Canal for movement between habitat areas to the north and south of the property. Populations of native pond turtle predators such as raccoons and opossums also typically increase in proximity to residential areas as a result of supplemental food sources and reduced coyote abundance (Crooks and Soule 1999).
Disturbance from Human Activity
Pond turtle observations have been known to decline in areas with increased human activity (Eric Hansen, pers. comm.). Human visits to areas occupied by turtles may result in lowered turtle abundance even when the visits are brief in duration and no more than one person, once per day (Eric Hansen, pers. comm.).
Habitat Fragmentation
Although pond turtles may travel less frequently than giant garter snakes, turtles occupying dynamic habitats such as the Natomas Basin may need to travel in response to changing conditions in their aquatic habitats, especially during the dry summer months. Connectivity between these areas may thus be important for turtle survival and reproduction, as well as the genetic interchange and patch-recolonization ability that may be necessary for the viability of the overall Basin population. Any loss or degradation of turtle movement corridors may thus yield effects that outreach the area of the directly impacted corridors.
Operation and Maintenance of Waterways
Water channels lose their habitat value for pond turtles when cleaned of aquatic vegetation, during low/no flow periods and when high water releases eliminate or alter basking sites, refugia, foraging areas or hatchling microhabitat (Holland 1991a; USFWS 1999). Water diversions or changes in land use within the area served by a canal or drain watershed may alter flows or even cause a canal or drain to be abandoned.
Water Quality
Aquatic communities may be greatly affected by surrounding land use. Urban areas can exert different and in some cases stronger effects than agricultural lands (Bury 1972; Moore and Palmer 2005). Residential developments typically result in increased traffic and fuel runoff, runoff of chemicals used for lawns and gardens, and increased stormwater volume and currents because of high coverage of impervious surfaces. Increased exposure to contaminants has been implicated in pond turtle population declines (Bury 1972; Holland 1991).
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City of Sacramento 4-10 Analysis of Effects on the Natomas Basin HCP
DISTRIBUTION
Information on CNDDB Occurrences
When information was compiled for the NBHCP in 2001, there were 117 known occurrences in California, of which 116 were considered extant. At that time, CNDDB did not list northwestern pond turtle occurrences in the Natomas Basin. As of 2005, there are 232 known occurrences in California, of which 231 are considered extant.
At this time, CNDDB does not list northwestern pond turtle occurrences within one mile of the Natomas Basin.
Other Information on Distribution and Abundance in Natomas Basin Surveys conducted in 2004 for the Natomas Basin Conservancy documented six northwestern pond turtle occurrences in the Natomas Basin. Two of these occurrences were just over one mile from the Greenbriar site, one was less than a mile from the proposed Natomas 130 reserve, and another was just over a mile from the proposed Spangler reserve. Many Natomas Basin canals are considered suitable habitat for this species, and high quality habitat exists near the Greenbriar and Natomas 130 sites, at Fisherman’s Lake.
4.2.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
Effects on the acreage of pond turtle habitat are summarized in Table 4-2. The proposed development at the Greenbriar site would result in the loss of an estimated 172 acres of pond turtle habitat from conditions at the time of the NBHCP (2001), and an additional 45 acres of rice habitat would be converted to upland at the Spangler site. Although the canal and marsh on the Greenbriar site were determined by the DEIR biologist to be of marginal quality and unlikely to support pond turtles, we have included these acres in our analysis for consistency with the broad habitat categories in the GIS analysis and NBHCP, and also because turtles may occasionally use the site as a movement corridor between higher quality habitats to the north and south of the site. At the proposed reserves, approximately 14 acres of pond turtle habitat would be created from non-habitat. Thus, the project as a whole would yield a net loss of 204 acres of turtle habitat.
Table 4-2
Change in Acreage of Northwestern Pond Turtle Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total
Change
Future Condition
with Project
Canals 1,162 -15.0 0.0 -1.4 -16.4 1,146
Ponds & seasonally wet areas 2,259 2.7 14.2 184 200.9 2,460 Rice 11,643 -160.0 - -228 -388.0 11,255
Riparian 91 0.0 0.0 - 0 91
Total 15,155 -172.4 14.2 -45.4 -203.5 14,951
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
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City of Sacramento 4-11 Analysis of Effects on the Natomas Basin HCP Effects on Quality of Habitat
Areas Adjacent to Developed Land or Highways
As discussed above in Mechanisms of Habitat Degradation, turtles traveling through the Lone Tree Canal or inhabiting other canals and wetlands downstream from the proposed development would likely be adversely affected by residential development through increased predation, disturbance, and degradation of aquatic habitat. (The adjacent Metro Air Park development does not include residential development.) Development of the Greenbriar site also would reduce the acreage of land draining into Lone Tree Canal, and thus could lead to reduced flows in the canal. In the absence of measures to offset this alteration, the quality of pond turtle habitat along Lone Tree Canal could be reduced by this loss of water. However, both the MAP HCP (see pages 70-71 in Thomas Reid Associates 2001) and the DEIR (mitigation measure 6.13-1) contain measures to assure the maintenance of aquatic habitat in Lone Tree Canal.
As described under Connectivity of Habitats in the Natomas Basin (in Section 3 of this report), the project and mitigation proposed in the DEIR for the Greenbriar project include measures that would substantially reduce the effects of development at the Greenbriar site on adjacent pond turtle habitat.
Alteration of Habitat Quality at Proposed Reserve Sites In addition to 14 acres of managed marsh that would be created from upland at the Natomas 130 reserve and the
2.7 acres of marsh that would be created along Lone Tree Canal, rice would be converted to marsh at the Spangler reserve enhancing 190 acres of habitat (184 acres of marsh and 6 acres of associated canals). This created and enhanced habitat would be preserved and managed for its habitat values.
These changes should considerably increase habitat quality for pond turtle, primarily because marsh provides much higher quality habitat for pond turtle than rice, management would include reduce adult mortality caused by human disturbance, and nesting and overwintering habitat would be created. Though a moderate level of uncertainty exists regarding the magnitude of benefits resulting from these enhancements, it is likely that they offset the habitat values that would be lost by development at the Greenbriar site.
Effects on Connectivity
The importance of habitat connectivity for this species is discussed in Mechanisms of Habitat Degradation, above. In the absence of effective mitigation, the project would reduce connectivity of pond turtle habitat by altering adjacent uplands, reducing water flows in the canal, and increasing predation and human disturbance.
However, as described under Connectivity of Habitats in the Natomas Basin (in Section 3 of this report), the project and mitigation proposed in the DEIR for the Greenbriar project include measures that would substantially reduce these effects. These measures include creation, enhancement and preservation of habitat (including tule bench along Lone Tree Canal) in the 30.6 acre reserve along Lone Tree Canal, a barrier/fencing to reduce predation and human disturbance effects, an additional assurance that aquatic habitat would be maintained in Lone Tree Canal, and funding to maintain and operate this conserved area. These measures would substantially reduce project’s effects on connectivity.
EFFECTS OF CONSTRUCTION-RELATED ACTIVITIES
Construction-related activities associated with the project could affect this species, though the Greenbriar site currently provides only marginally suitable habitat. Also, construction-related degradation of water quality in Lone Tree Canal could affect turtles downstream. In addition, pond turtles could be harmed during restoration activities at the proposed Natomas 130 reserve, by crushing under equipment or entombment in their winter burrows. Measures to avoid and minimize take of northwestern pond turtles and giant garter snakes, described in the Greenbriar project DEIR and Natomas Basin HCP, would reduce any direct construction-related effects on
Greenbriar Development Project EDAW
City of Sacramento 4-12 Analysis of Effects on the Natomas Basin HCP this species. These measures where listed in Section 4.1 Giant Garter Snake under Effects of Construction-related Activities.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
As discussed above in Mechanisms of Habitat Degradation, in the absence of avoidance and minimization northwestern pond turtles would likely experience increased predation near the proposed residential development because of the increased abundance of domestic dogs and cats, as well as human-associated raccoons, skunks and opossums. The increased human population in the area would also increase the potential for human activity near the canal, which may lead to site avoidance by turtles (Eric Hansen, pers. comm.). Mortality because of vehicle strikes may also increase on existing roads because of the increased traffic that the project would produce.
However, as described under Connectivity of Habitats in the Natomas Basin (in Section 3 of this report), the project and the DEIR mitigation include measures that would substantially reduce these effects.
OVERALL EFFECT ON POPULATION VIABILITY
The project would cause both adverse and beneficial effects on the northwestern pond turtle population in the Natomas Basin. Beneficial effects would include preserving, creating, and enhancing habitat at the reserve sites, preserving a corridor along Lone Tree Canal, and contributing to the connectivity of habitat and existing TNBC reserves adjacent to or near the proposed reserves. Adverse effects would include a reduction in the total acreage of habitat, and possibly degradation of habitat near the Greenbriar site and reduced connectivity along Lone Tree Canal due to increased human disturbance and predation. The DEIR mitigation would reduce these adverse effects and ensure that connectivity of pond turtle habitat was maintained along Lone Tree Canal.
Overall, the project would not adversely affect pond turtle. The loss of habitat acreage would be more than offset by the increased habitat quality resulting from the preservation of habitat, conversion of rice to marsh, and management of rice to enhance habitats. The project would have a beneficial effect on pond turtle habitat largely because the created marsh would provide much higher quality habitat for pond turtle than rice (USFWS 2003).
Also, the project (with the DEIR mitigation) would conserve connectivity and habitat for pond turtle along Lone Tree Canal and near proposed reserves in the southern and central Basin. These beneficial effects on habitat and connectivity may be sufficient to increase the viability of the Natomas Basin’s northwestern pond turtle population.
4.3 SWAINSON’S HAWK
4.3.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
Swainson’s hawks (Buteo swainsoni) are most commonly found in grasslands, low shrublands, and agricultural habitats that include large trees for nesting. Land cover types designated as Swainson’s hawk nesting habitat in the NBHCP include oak groves, tree groves, and riparian. These habitats are suitable for nesting only where adjacent to adequate foraging habitat. Land cover types designated as Swainson’s hawk foraging habitat in the NBHCP include alfalfa, grassland, idle, non-rice crops, pasture, and ruderal. Swainson’s hawks will also nest in these foraging habitats if large trees are available; however, isolated trees may be less suitable for nesting than trees in groves or riparian areas.
Prey abundance and accessibility (for capture) are the most important features determining the suitability of hawk foraging habitat. In addition, agricultural operations (e.g., mowing, flood irrigation) have a substantial influence
Greenbriar Development Project EDAW
City of Sacramento 4-13 Analysis of Effects on the Natomas Basin HCP on the accessibility of prey and thus create important foraging opportunities for Swainson’s hawk (Estep 1989).
Crops which are tall and dense enough to preclude the capture of prey (e.g., corn) do not provide suitable habitat except around field margins, but prey in these habitats are accessible during and immediately following harvest.
Other crops (e.g., tomato, sugar beet) are tall and dense enough to inhibit but not to prevent the capture of prey during the growing season, and also provide valuable foraging opportunities during their harvest. Alfalfa, idle crop land, and most ruderal land and grassland have low and or open vegetation that doesn’t impede prey capture, but prey abundance varies among these habitats and so does the frequency of agricultural operations (which are absent from ruderal land and grassland). Based on these considerations, we have divided crops and other foraging habitats into four categories of quality (i.e., low, moderate, high-moderate, and high) (Table 2-3). The basis for this classification is described in detail in the methods section (Section 2) under Habitat Quality.
Home Range Size and Movement
Although the most important foraging habitat for Swainson’s hawks lies within a one-mile radius of each nest (City of Sacramento et al. 2003), Swainson’s hawks have been recorded foraging up to 18.6 miles from nest sites (Estep 1989). Any habitat within this foraging distance may provide food at some time in the breeding season that is necessary for reproductive success. In a dynamic agricultural environment such as the Natomas Basin, the area required for hawk foraging depends on the time of season, crop cycle, crop type, and discing/harvest schedule, as these factors affect the abundance and availability of prey (City of Sacramento et al. 2003). Swainson’s hawk foraging ranges during the breeding season have been estimated at approximately 1,000-7,000 acres (Bechard 1982, Estep 1989, Johnsgard 1990).
Mechanisms of Habitat Degradation
Reduction of Prey Base
The order of habitat suitability for Swainson’s hawks listed above was determined by the abundance and availability of prey. Conversion of higher-suitability habitats to lower-suitability habitats would be accompanied by a reduction in prey base that may reduce nest survival or the fat reserves required by hawks for their fall migration to Central Mexico (Swainson’s Hawk Technical Advisory Committee 2001), without any change in overall habitat acreage.
Changes in the hawks’ rodent prey base may also result from impacts of residential development to adjacent mammalian predator communities. Crooks and Soule (1999) quantified the impacts of domestic cats on rodents and other small animals. They estimated that the average domestic cat population in moderately sized fragments (~50 acres of upland habitat bordered by 100 residences) returns about 840 rodents, 525 birds, and 595 lizards to residences each year. Assuming that cats do not bring back all prey that they kill, actual impacts to hawk prey numbers are probably even greater. Crooks and Soule (1999) also documented increased extirpations of songbird species in habitat fragments with higher densities of cats, raccoons and opossums, all of which often increase in proximity to residential development. Although rodents are the primary prey of breeding Swainson’s hawks in the Natomas Basin, songbirds also contribute to their diets.
Several studies indicate that the abundance of bird species is lower near residential development. Compared to undeveloped areas at least 2,297 feet from development, Odell and Knight (2001) demonstrated lower densities of the hawks’ secondary songbird prey within 1,083 feet of sparse residential development (less than 0.4 dwelling units/acre); impacts of higher density development are expected to be greater. Similarly, Blair (1996) reported 1/3 fewer bird species in lands adjacent to residential development, when compared to habitat preserves in the same area. Increased predation on the hawks’ rodent prey is likely to extend between 98–590 feet from homes because of domestic cats, 590–1,083 feet from homes because of domestic dogs, and farther because of increased populations of small wild predators such as opossums and foxes (Odell and Knight 2001).
Greenbriar Development Project EDAW
City of Sacramento 4-14 Analysis of Effects on the Natomas Basin HCP Habitat Fragmentation and Reduced Patch Size
The contiguity of foraging habitat and its placement near nest sites may also affect hawk foraging (and subsequently breeding) success. Longer foraging flights carry higher energetic costs than foraging closer to nests, and reduce the amount of time adults are present to defend nests from predators. Similarly, there may be a threshold of required habitat area near each nest, related to the foraging ranges discussed above, such that habitat loss beyond this threshold would result in a greater impact to nest survival than habitat loss from a larger area.
The diversity and abundance of Swainson’s hawk prey have also been reported to decline in fragmented habitat (Crooks et al. 2001; Helzer and Jelinski 1999; Hinsley et al. 1995).
Increased Predation
Corvids (crows, magpies) and great horned owls are the most common predators of Swainson’s hawk eggs and nestlings (England et al. 1997). Corvid populations typically increase near human settlement because of the supplemental food source of human refuse and additional perches provided by urban trees, street lights, and other infrastructure (Steenhof et al. 1993; Marzluff et al. 2001). This increase in predator abundance may result in increased nest predation near residential development.
Nest Disturbance
Swainson’s hawk responses to nest disturbance vary with each nesting pair and the timing, regularity, and nature of the disturbance. Although some researchers have described disturbed nest sites that successfully fledge young (Estep 1989; England et al. 1995), others have recorded nest abandonment in response to human activity, especially during nest building and incubation (Bent 1937; Stahlecker 1975). In addition to nest abandonment, significant disturbances near hawk nests may interfere with parental care and feeding of young in a way that reduces nest success.
DISTRIBUTION
Information on CNDDB Occurrences
When information was compiled for the NBHCP in 2001, there were 892 known occurrences in California, of which 882 were considered extant. The NBHCP did not list CNDDB occurrences for the Natomas Basin, but local surveys (described below) provided extensive data. As of 2005, there are 1,380 known Swainson’s hawk occurrences in California, of which 1,350 are considered extant. At this time, 35 occurrences are known in the Natomas Basin, of which 34 are considered extant. Sixteen additional occurrences are known within one mile of the Basin, all of which are considered extant. Of these occurrences, two are within one mile of the Greenbriar site and eight are within one mile of the proposed reserve sites. All ten of these occurrences are considered extant.
Other Information on Distribution and Abundance in Natomas Basin Estep (2001) indicates that nesting sites and foraging activity occur throughout the Basin, depending on the availability of suitable nest trees in proximity to upland foraging areas. The most recent survey of the Natomas Basin at the time the Habitat Conservation Plan was prepared located 62 breeding sites in or immediately adjacent to the Basin (Swainson’s Hawk Technical Advisory Committee 2001). Hawks nesting at the 35 sites adjacent to the Basin were located along the Sacramento River and may have depended on the Basin’s foraging habitat for their survival and reproduction. The NBHCP asserts that the Swainson’s hawk population supported by the Natomas Basin is “important to the continued viability” of the species, which has been estimated by the California Department of Fish and Game to have declined by 94% from historical conditions in the state (Bloom 1980, California Department of Fish and Game 1989).
The most recent survey published by the Natomas Basin Conservancy mapped 89 nest sites in or adjacent to the Basin in 2004, of which 59 were active in that year. Each of these nests was within the 18.6 mile recorded
Greenbriar Development Project EDAW
City of Sacramento 4-15 Analysis of Effects on the Natomas Basin HCP foraging distance from the project and proposed reserve sites and may be affected by changes in land cover at those sites. The Natomas Basin Conservancy has mapped five nests within one mile of the Greenbriar site, two of which were active in 2004, and 12 nests within one mile of the proposed Natomas 130 reserve, six of which were active in 2004. No Swainson’s hawk nests have been mapped within one mile of the proposed Spangler reserve.
The most recent monitoring report prepared for The Natomas Basin Conservancy (Jones & Stokes 2005) also contains information on population trends in the Natomas Basin. In 2004, the number of successful nests increased by five, but the downward trend in number of young per successful nest has continued, resulting in reproduction relatively similar to previous years (1999–2003).
4.3.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
The project would not change the acreage of Swainson’s hawk nesting habitat at the Greenbriar or proposed reserve sites from current (2005) conditions or conditions at the time of the NBHCP (2001), but would preserve two acres of nesting habitat.
The project’s effects on foraging habitat are summarized in Table 4-3. The project would reduce the acreage of Swainson’s hawk foraging habitat in the Natomas Basin from conditions at the time of the NBHCP (2001). The proposed development at the Greenbriar site would reduce foraging habitat by an estimated 313 acres from conditions in 2001. At the proposed Spangler and Natomas 130 reserves, foraging habitat would increase by 91 acres. Thus, the project as a whole would yield a net loss of 222 acres of Swainson’s hawk foraging habitat.
Table 4-3
Change in Acreage of Swainson’s Hawk Foraging Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total Change Future Condition
with Project
Alfalfa 368 - 14.2 45.4 59.6 428
Grassland 284 26.5 - - 26.5 311
Idle 422 -62.5 - - -62.5 360
Non-rice crops 9,533 -234.1 -28.4 - -262.5 9,271
Pasture 494 -33.8 - - -33.8 460
Ruderal 370 -9.2 - - -9.2 361
Upland marsh components 547 - 4.3 55.2 59.5 607
Total 12,018 -313.1 -9.9 100.6 -222.4 11,796
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
Effects on Quality of Habitat
Areas Adjacent to Developed Land or Highways
Although the expanded urban area that would be created by the Greenbriar project would result in a net reduction of areas within 800 feet or one mile of urban development or highways, the project would expand a gradient of urban influence into the previously unaffected area to the north of the property and could increase the urban
Greenbriar Development Project EDAW
City of Sacramento 4-16 Analysis of Effects on the Natomas Basin HCP influence on the agricultural land to the southwest. The impacts to Swainson’s hawk prey in this area that could occur as a result of proximity to development are discussed under Mechanisms of Habitat Degradation, above.
However, the existing roads that border the site, would function as partial barriers that limit the extent of urban influences on adjacent agricultural lands.
The current land use immediately to the north of the Greenbriar site is rice and as such does not support Swainson’s hawk habitat except when fallowed. However, the creation of hawk habitat at the Greenbriar site between 2001 and 2005 attests to the potential for the area to the north to become hawk habitat in the future. The recent creation of habitat at the Greenbriar site resulted from the conversion of the rice acreage to non-rice crops and fallow agriculture. The current land use to the southwest of the property is idle cropland, which supports Swainson’s hawk habitat.
Altered Habitat Quality at Proposed Reserve and Mitigation Sites The project with the DEIR mitigation would enhance and preserve at least 190 acres of foraging habitat (26.5 acres of grassland along Lone Tree Canal, 59.7 acres of alfalfa [or other high quality foraging habitat] and 59.5 acres of upland marsh components at Spangler and Natomas 130, and at least an additional 49 acres of high quality foraging habitat required by the DEIR mitigation). Habitat at the unspecified DEIR mitigation site(s) and at the proposed Spangler and Natomas 130 reserves would be actively managed with the primary goal of providing high quality foraging habitat.
Conservation of the corridor along Lone Tree canal may improve its value as foraging habitat because it would be converted to perennial grassland that might have higher habitat value than the corridor’s current or recent agricultural land cover. This corridor, however, would be a relatively narrow band of potential habitat surrounded by urban development, and this setting might limit its use by Swainson’s hawk. Consequently, this proposed corridor was considered to provide only low quality foraging habitat.
Habitat quality for Swainson’s hawks would increase in the remaining upland habitat at the proposed Natomas 130 reserve because it would be managed to provide high quality Swainson’s hawk habitat.
The proposed Spangler property does not currently function as Swainson’s hawk habitat except when fallowed.
One hundred eighty four acres of this proposed reserve would be restored to marsh (with upland components providing foraging habitat) and the remainder (45 acres) would be converted to upland managed to provide high quality foraging habitat for Swainson’s hawk. Although the Spangler property is within the 18.6 mile maximum foraging distance from all known nests in the Basin, its distance from the Greenbriar site would limit its benefit as foraging habitat for hawks affected by the project regardless of the reserve’s management.
Mitigation measure 6.13-2 of the DEIR requires the enhancement and preservation of at least 49 acres to provide high quality foraging habitat that would prevent a net loss of foraging habitat values. This mitigation is in addition to the proposed reserves.
The effect of the Greenbriar project with the DEIR mitigation on the quality of Swainson’s hawk foraging habitat was evaluated through three analyses:
1. acres of foraging habitat in low, m oderate and high quality categories;
2. total acres of foraging habitat available per month; and
3. total foraging habitat available each month expressed as an equivalent acreage of high quality foraging habitat.
The first two analyses (acres by habitat quality category and monthly availability) were conducted as in the NBHCP, and the third was developed for this effects analysis. All three methods are described in detail in the methods section.
The acres of habitat types at the Greenbriar, proposed reserve and DEIR mitigation sites with and without the project that were used in these analyses are shown in Table 2-2, and are also tabulated in tables 3-1 and 4-3.
Greenbriar Development Project EDAW
City of Sacramento 4-17 Analysis of Effects on the Natomas Basin HCP Though the project would result in a net loss of habitat acreage, an increased percentage of the remaining habitat would be in the high quality category (Exhibit 3a). This increase in high quality habitat would result from the creation and enhancement of habitat at the Spangler, Natomas 130, and the DEIR mitigation sites. Upland habitat at the proposed Natomas 130 reserve would be enhanced, 45 acres of high quality foraging habitat would be created at the Spangler site and to provide DEIR mitigation at least 49 acres of land would be enhanced and managed to provide high quality foraging habitat for Swainson’s hawk.
Based on the analysis approach in the NBHCP, the project also would result in greater availability of foraging habitat during April–September, despite causing a net loss in overall acreage of habitat (Exhibit 3). (However, this approach assumes that row and field crops are not available to foraging hawks except at harvest, and thus underestimates the acreage of foraging habitat available, particularly during April–May, which is prior to the harvest of row and field crops in the Natomas Basin.)
Based on EDAW’s analysis approach, total foraging resources would be comparable with and without the project.
At the Greenbriar, proposed reserve, and DEIR mitigation sites, during April–June, slightly greater foraging resources would be available with the project (the equivalent of 129 acres of high quality foraging habitat with versus 122 acres without the project), while during July–September there would be less (129 versus 140 acres in July–August and 162 acres in September) (Exhibit 4). (Throughout the Natomas Basin, during July–September, more foraging resources are available because that is when most crops are harvested [CH2M HILL 2003].) Effects on Connectivity
With the exception of the 250-foot wide proposed conservation easement along Lone Tree Canal, the Greenbriar site would become urban land cover, which would reduce upland connectivity between the Swainson’s hawk nests south of the site and foraging habitat north of the Greenbriar site. This connectivity will already be reduced by development of the Metro Air Park, which would leave the Greenbriar site as the last north-south habitat corridor in the Basin east of the mile-wide corridor along the Sacramento River. Although nesting hawks have the ability to fly past a developed Greenbriar site to northern foraging areas, they may be less likely to use foraging habitat beyond this 546-acre urban area because of the energetic cost and additional time away from the nest required by the flight. (Long foraging flights are more likely to follow lines of contiguous habitat, as hawks may scan for prey along the entire flight.)
For Swainson’s hawk, the consequences of this potential habitat fragmentation depend on the distribution of foraging and nesting habitat under the future condition of the Natomas Basin resulting from the NBHCP.
Currently, there is relatively little foraging habitat north and east of the Greenbriar site, and this habitat is already fragmented. There also is very little potential nesting habitat north and east of the Greenbriar site. (Both foraging habitat and nesting habitat are concentrated to the south and west of the Greenbriar site.) Thus, changes in land cover at the Greenbriar site are unlikely to cause substantial alterations of movement of Swainson’s hawks across the Greenbriar site. However, the distribution of Swainson’s hawk habitat in the Natomas Basin could change, and under the future condition of the Natomas Basin there would be non-urban land both north of the Greenbriar site in the central Natomas Basin and to the south of the Greenbriar site in the southern Natomas Basin. Thus, the potential for effects on connectivity of Swainson’s hawk habitat can not be discounted.
The potential effects of habitat fragmentation and reduced upland connectivity on Swainson’s hawk prey are discussed under Mechanisms of Habitat Degradation, above.
EFFECTS OF CONSTRUCTION-RELATED ACTIVITIES
Construction at the Greenbriar site and habitat management at the proposed reserve sites has the potential to displace and/or disturb nesting Swainson’s hawks. Nest disturbance from the operation of heavy construction equipment and continued activity near nest sites could cause nest abandonment or interfere with the incubation and feeding of young in a way that reduces nesting success.
Greenbriar Development Project EDAW
City of Sacramento 4-18 Analysis of Effects on the Natomas Basin HCP The DEIR for the Greenbriar project and the Natomas Basin HCP both include measures to avoid and minimize construction-related effects on Swainson’s hawks. In the DEIR, these measures include:
► Pre-construction surveys shall be conducted for Swainson’s hawk and other raptors no more than 14 days and no less than 7 days prior to the beginning of any construction activity between March 15 and August 15. The survey area shall include all potential nesting sites located within ½ mile of the project and mitigation-sites ► Should nesting be discovered within the survey area, a qualified biologist shall notify DFG and no new disturbance shall occur within 1/2 mile of the nest until the nest is no longer active or appropriate avoidance measures are approved by DFG to ensure that the nest is adequately protected. Potential mitigation measures may include visual screening and timing restrictions for construction activity. Monitoring (funded by the project applicants) of active nests by a DFG-approved raptor biologist shall be required to determine if project construction is disturbing Swainson's hawks at the nest site. Exact implementation of this measure shall be based on specific information at the project site.
These measures should adequately reduce the impacts to Swainson’s hawks that may result specifically from construction-related activities. Any construction-related displacement of hawks from foraging habitat is akin to habitat loss, as discussed above.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
The proposed development is located within a ½ mile of one Swainson’s hawk nest active in 2005. Although this nest tree was cut down (without authorization) during the breeding season, the pair attempted to renest in another nearby tree and may return in future years. This breeding pair would be close enough to the Greenbriar site that human disturbance from the residential development proposed at the Greenbriar site may cause nest abandonment (Bent 1937; Stahlecker 1975) or interfere with incubation and feeding of young in a way that reduces reproductive success. Predation of eggs and young chicks by crows and other corvids may also increase as a result of increased human refuse and infrastructure at the Greenbriar site (Steenhof et al. 1993; Marzluff et al. 2001). Mortality because of vehicle strikes may also increase on existing roads because of the increased traffic associated with the project. Human-wildlife conflicts are unlikely to occur at the proposed reserves.
OVERALL EFFECT ON POPULATION VIABILITY
The project would cause both adverse and beneficial effects on the Swainson’s hawk population nesting and foraging in the Natomas Basin. Adverse effects would include a reduction in the total acreage of foraging habitat, fragmentation, and possibly degradation of habitat near the Greenbriar site, and a reduction in habitat available to hawks nesting at reserves near the Greenbriar site. Beneficial effects would include increasing the acreage of high quality habitat, preserving high quality habitat within a mile of TNBC reserves (or of the Swainson’s Hawk zone along the Sacramento River), and possibly contributing to the connectivity of foraging habitat adjacent to the mitigation site(s) required by mitigation measure 6.13-2.
Overall, based on the USFWS interpretation of effects on Swainson’s hawk due to the NBHCP (USFWS 2003), the Greenbriar project would not be expected to adversely affect the viability of the Swainson’s hawk population in the Natomas Basin. Because the availability of foraging habitat during April-July is considered to limit the abundance and reproductive success of Swainson’s hawk in the Natomas Basin (CH2M HILL 2003; USFWS 2003), and the project would not reduce the acreage of habitat available during these months, the project would not be expected to reduce the number of hawks nesting in the Natomas Basin or their reproductive success.
Greenbriar Development Project EDAW
City of Sacramento 4-19 Analysis of Effects on the Natomas Basin HCP
4.4 BURROWING OWL
4.4.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
Burrowing owls (Athene cunicularia hypugea) typically inhabit grasslands, savannahs and other open habitats with low-lying vegetation. Land cover types designated as burrowing owl habitat in the NBHCP include alfalfa, grassland and pasture. Owls are also known to nest and forage in idle agricultural fields, ruderal fields and the edges of cultivated fields, although these areas provide lower quality habitat than native grasslands. The NBHCP also describes canals as potential nesting habitat for burrowing owls, although it does not include canals in the habitat table for this species. Levees and upper banks of canals and ditches provide burrowing owl nesting habitat when canal maintenance activities are limited, water levels remain below nesting burrows and the area remains relatively undisturbed. Small mammal populations (particularly California ground squirrels) are the most important feature in burrowing owl habitat, as these mammals provide both food and nesting burrows for the owls. When natural burrows are scarce, burrowing owls will also nest in artificial structures such as culverts.
They often nest in elevated areas such as berms and levees, where they may scan adjacent lands for predators and prey. Burrowing owls feed primarily on large insects and rodents, and will also feed opportunistically on birds, reptiles and amphibians (NatureServe 2005).
Home Range Size and Movement
Although the more northern burrowing owl populations migrate seasonally, burrowing owls are year-round residents of the Natomas Basin. The owls often form loose colonies, with nest burrows 46–2,952 feet apart (Ross 1974; Gleason 1978). Surprisingly few data are available on home range size for this species. Published estimates vary from 0.05–1.86 square miles (Haug and Oliphant 1990).
Mechanisms of Habitat Degradation
Increased Predation
Ground- and burrow-nesting birds such as burrowing owls are particularly vulnerable to predation by domestic dogs and cats. Many wild predators of burrowing owls also increase near human habitation. In proximity to residential development, dominant carnivores such as coyotes are typically replaced by foxes, opossums, skunks, and other small predators that feed on burrowing owls (Sheffield 1997; Wellicome 1997b; Crooks and Soule 1999). Avian predators such as great-horned owls and crows may also increase in proximity to residential development, in response to introduced nesting trees, increased food supplies and increased hunting perches such as street lights and other infrastructure (Steenhof et al. 1993; Marzluff et al. 2001). This increase in predator abundance would likely result in increased predation of burrowing owl nests and adults near residential development.
Reduction of Prey Base
Changes in the owls’ prey base may result from residential development affecting adjacent mammalian predator communities. Rodents and insects are the primary prey of burrowing owls; songbirds also contribute to their diets (NatureServe 2005). Crooks and Soule (1999) quantified the effects of domestic cats on small animals. They estimated that the average domestic cat population in moderately sized fragments (~50 acres of upland habitat bordered by 100 residences) returns about 840 rodents, 525 birds and 595 lizards to residences each year.
Assuming that cats do not bring back all prey that they kill, actual effects on prey numbers are probably even greater. Crooks and Soule (1999) documented increased extirpations of songbird species in habitat fragments with
Greenbriar Development Project EDAW
City of Sacramento 4-20 Analysis of Effects on the Natomas Basin HCP higher densities of cats, raccoons and opossums, all of which often increase in proximity to residential development.
Compared to undeveloped areas at least 2,296 feet from development, Odell and Knight (2001) demonstrated lower densities of the owls’ secondary songbird prey within 1,083 feet of sparse residential development (about
0.4 houses per acre); impacts of higher density development are expected to be greater. Similarly, Blair (1996) reported 1/3 fewer bird species in lands adjacent to residential development, when compared to habitat preserves in the same area.
Habitat Fragmentation and Reduced Patch Size
Habitat fragmentation has been implicated as a major cause of population decline in grassland birds in general, and is likely to specifically impact burrowing owls. Helzer and Jelinski (1999) found both overall avian species richness and the presence of several common grassland species to increase with the size of habitat patches (especially when >124 acres) and decrease with the perimeter-area ratio of these patches, which reflects the proportion of habitat influenced by edge effects.
In fragments 5–250 acres in size, Crooks et al. (2001) found fragment size to be the most important factor determining extinction and colonization of songbirds. No fragments up to 247 acres in size were large enough to support the full complement of native bird species with 95% probability over a 100-year period. Burrowing owls forage in larger habitat patches than the smaller birds studied by Crooks et al. (2001), and are likely to be similarly affected by fragmentation. Hinsley et al. (1995) also demonstrated the instability of bird populations in habitat fragments.
Nest Disturbance
Although burrowing owls are tolerant of human activity outside of the breeding season, they have been shown to abandon nests if disturbed during incubation. In addition to nest abandonment, significant disturbances near owl nests may interfere with parental care and feeding of young in a way that reduces nest success.
DISTRIBUTION
Information on CNDDB Occurrences
When information was compiled for the NBHCP in 2001, there were 370 known occurrences in California, of which 300 were considered extant. At that time, three occurrences were known from the Natomas Basin, all of which were considered extant. As of 2005, there are 709 known occurrences in California, of which 671 are considered extant. At this time, seven occurrences are known in the Natomas Basin, of which six are considered extant. Of these occurrences, one is within a mile of the Greenbriar site, and none are within a mile of the proposed reserve sites.
Other Information on Distribution and Abundance in Natomas Basin No systematic surveys have been conducted to determine burrowing owl distribution or abundance across the Natomas Basin. A burrowing owl was incidentally observed in a culvert on the southwestern portion of the Greenbriar site during the March 17, 2005 site visit. A number of owl pellets and whitewash were also observed, indicating extended use of the site by at least one owl for roosting and foraging over a period of time, and possible nesting. During biological effectiveness monitoring for the NBHCP, burrowing owls were observed in the eastern Basin south of Elverta Road and in the central Basin along Highway 99 (approximately 1.3 miles north of the Greenbriar site) (Jones & Stokes 2005). Burrowing owls have also been incidentally observed east of the Greenbriar site along Elkhorn Blvd. and west of the Greenbriar site on the Metro Air Park and Sacramento International Airport.
Greenbriar Development Project EDAW
City of Sacramento 4-21 Analysis of Effects on the Natomas Basin HCP
4.4.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
The project’s effects on foraging habitat for burrowing owl are summarized in Table 4-4. The project would reduce the acreage of burrowing owl habitat in the Natomas Basin from conditions at the time of the NBHCP (2001). The proposed development at the Greenbriar site would reduce habitat by an estimated 94 acres from conditions in 2001. At the proposed reserves, 118 acres of burrowing owl habitat would be created (assuming the Swainson’s hawk foraging also provided burrowing owl habitat). Thus, the project as a whole would yield a net gain of 24 acres of burrowing owl habitat. Additional burrowing owl foraging habitat may be created by the enhancement and management of at least 49 acres of land to provide high quality foraging habitat for Swainson’s hawk that is required by mitigation measure 6-13.2 of the DEIR.
Table 4-4
Change in Acreage of Burrowing Owl Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total Change Future Condition
with Project
Alfalfa 368 - 14.2 45.4 59.6 428
Canals 1,162 -15.0 0.0 -1.4 -16.4 1,146
Grassland 284 26.5 - - 26.5 311
Idle 422 -62.5 - - -62.5 360
Pasture 494 -33.8 - - -33.8 460
Ruderal 370 -9.2 - - -9.2 361
Upland marsh components 547 - 4.3 55.2 59.5 607
Total 3,647 -94.1 18.5 99.2 23.7 3,673
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
Effects on Quality of Habitat
Areas Adjacent to Developed Land or Highways
Although the expanded urban area that would be created at the Greenbriar site would result in a net reduction of areas within 800 feet or 1 mile of development, the project would expand a gradient of urban influence into the previously unaffected area to the north of the property and could increase the urban influence in the idle field to the southwest. The potential effects on burrowing owls and their prey in these areas are discussed under Mechanisms of Habitat Degradation, above. These adverse effects, however, would be limited by Interstate 5 along the Greenbriar site’s southern border, and by Elkhorn Boulevard (which would be expanded to six lanes) that would serve as partial barriers between development on the Greenbriar site and adjacent agricultural lands.
The current land use immediately to the north of the Greenbriar site is rice and as such does not support burrowing owl habitat. However, the creation of burrowing owl habitat at the Greenbriar site between 2001 and 2005 attests to the potential for the area to the north to become burrowing owl habitat in the future. The habitat creation on the Greenbriar site resulted from the conversion of a portion of the rice acreage to fallow agriculture.
The current land use to the southwest of the property is fallow agriculture, which supports burrowing owl habitat.
Greenbriar Development Project EDAW
City of Sacramento 4-22 Analysis of Effects on the Natomas Basin HCP Altered Habitat Quality at Proposed Reserve and Mitigation Sites In addition to habitat lost due to development of the Greenbriar site, and created at the proposed reserves, the quality of burrowing owl habitat could be altered at the conserved corridor along Lone Tree Canal, the proposed Spangler and Natomas 130 reserves, and the mitigation site that would be required by mitigation measure 6.13-2 of the DEIR.
Conservation of the corridor along Lone Tree canal may improve its value as foraging habitat because it would be converted to perennial grassland that might have higher habitat value. This corridor, however, would be a relatively narrow band of potential habitat surrounded by urban development, and this setting might limit its use by burrowing owl.
At all of the proposed reserves, management practices would enhance habitat for burrowing owl. These enhancements include maintaining buffers in as natural a state as possible, controlling feral cats if necessary, and reducing human disturbance due to trespassers (City of Sacramento et al. 2003, John Roberts, TNBC, personal communication). Also, preservation of habitat, even without enhancement measures, provides some benefits, including that it precludes land use changes that would eliminate habitat, and should reduce or eliminate uses that could cause mortality of individuals.
In addition to habitat enhancement at the proposed reserves, mitigation measure 6.13-2 of the DEIR requires that at least 49 acres be enhanced to provide high quality foraging habitat. This mitigation could also benefit burrowing owls. This mitigation land will be managed to provide high quality foraging habitat for Swainson’s hawk, but would also enhance foraging habitat for burrowing owl.
Effects on Connectivity
With the exception of the 250-foot wide conservation easement proposed along Lone Tree Canal, the development at the Greenbriar site would eliminate the existing contiguity of upland habitats to the north and south of the site. This connectivity will already be substantially reduced by development at the Metro Air Park, which would leave the Greenbriar site as the last north-south corridor of habitat in the Basin east of the mile-wide corridor along the Sacramento River. Owl survival and reproduction are likely to be higher in larger, more contiguous habitat areas. Connectivity benefits owls by providing greater ease of locating mates, greater flexibility in year-round foraging opportunities, and safer passages for juvenile dispersal. The potential effects of reduced connectivity on upland birds in general are discussed under Mechanisms of Habitat Degradation, above.
The proposed reserves and mitigation site(s) could increase connectivity of burrowing owl habitat elsewhere in the Natomas Basin. If larger, more contiguous areas of habitat resulted from the creation of these reserves, this would benefit owl survival and reproduction. Other foraging habitat is available near the Natomas 130 site, and thus this proposed reserve would result in larger more continuous areas of habitat (Jones & Stokes 2005). The land cover surrounding the Spangler property is primarily rice (Jones & Stokes 2005)
EFFECTS OF CONSTRUCTION-RELATED ACTIVITIES
Earth-moving activities may trap or injure owls in their burrows, and disturbance near nests may cause nest abandonment. Both the Greenbriar DEIR and Natomas Basin HCP require comparable measures to avoid impacts to burrowing owls during construction. The DEIR measures include:
a. No more than 30 days and no less than 14 day prior to project site grading, a qualified biologist shall conduct focused surveys for burrowing owls in areas of suitable habitat on and within 300 feet of the project site.
Surveys shall be conducted in accordance with DFG protocol (DFG 1995). b. If no occupied burrows are found in the survey area, a letter report documenting survey methods and findings shall be submitted to DFG, and no further mitigation is necessary.
Greenbriar Development Project EDAW
City of Sacramento 4-23 Analysis of Effects on the Natomas Basin HCP c. If occupied burrows are found in the survey area, imp acts shall be avoided by establishing a buffer of 165 feet during the non-breeding season (September 1 through January 31) or 300 feet during the breeding season (February 1 through August 31). The size of the buffer area may be adjusted if a qualified biologist and DFG determine it would not be likely to have adverse effects. No project activity shall commence within the buffer area until a qualified biologist confirms that the burrow is no longer occupied. If the burrow is occupied by a nesting pair, a minimum of 6.5 acres of foraging habitat contiguous to the burrow shall be preserved until the breeding season is over.
d. If impacts to occupied burrows are unavoidable, on- site passive relocation techniques may be used if approved by DFG to encourage owls to move to alternative burrows outside of the impact area. However, no occupied burrows shall be disturbed during the nesting season unless a qualified biologist verifies through non-invasive methods that the burrow is no longer occupied. Foraging habitat for relocated pairs shall be provided in accordance with guidelines provided by DFG (1995). DFG guidelines recommend a minimum of
6.5 acres of foraging habitat per pair or unpaired resident bird, be acquired and permanently protected. e. If relocation of the owls is approved for the site by DFG, the developer shall hire a qualified biologist to prepare a plan for relocating the owls to a suitable site. The relocation plan must include: (a) the location of the nest and owls proposed for relocation; (b) the location of the proposed relocation-site; (c) the number of owls involved and the time of year when the relocation is proposed to take place; (d) the name and credentials of the biologist who will be retained to supervise the relocation; (e) the proposed method of capture and transport for the owls to the new site; (f) a description of the site preparations at the relocation-site (e.g., enhancement of existing burrows, creation of artificial burrows, one-time or long-term vegetation control, etc.); and (g) a description of efforts and funding support proposed to monitor the relocation. Relocation options may include passive relocation to another area of the site not subject to disturbance through one way doors on burrow openings, or construction of artificial burrows in accordance DFG guidelines. f. The project applicant shall implement Mitigation M easure 6.12-2 to mitigate for the loss of burrowing owl foraging habitat.
By following these measures, the potential for injury, entrapment, and nest abandonment would be reduced.
However, nests may be abandoned because of loss of the surrounding foraging habitat during construction, and owl viability at relocation sites is not guaranteed.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
On the remaining habitat adjacent to the proposed development, human activity may cause owl nest abandonment or interfere with the incubation and feeding of young in a way that reduces reproductive success. Increased owl predation would also likely occur in proximity to the proposed development, as a result of the typical increase in human-associated owl predators discussed above under Mechanisms of Habitat Degradation. Increased predation by domestic cats is likely to extend between 98–540 feet from homes, predation by domestic dogs is likely to extend between 540–990 feet from homes, and increased predation by wild predators is likely to extend farther (Odell and Knight 2001). Mortality because of vehicle strikes may also increase on existing roads because of the increased traffic that would result from the project.
OVERALL EFFECT ON POPULATION VIABILITY
The Greenbriar project with the DEIR mitigation would cause both adverse and beneficial effects on burrowing owl. Adverse effects would include loss of occupied habitat, and fragmentation and some degradation of habitat adjacent to development at the Greenbriar site. Beneficial effects would include a net increase in acreage of foraging habitat, and preservation and enhancement of at least 197 acres of habitat, and possibly increased connectivity of habitats in the vicinity of the mitigation lands. Overall, the project would likely result in a beneficial effect on burrowing owl. However, the project is unlikely to have a substantial effect on burrowing
Greenbriar Development Project EDAW
City of Sacramento 4-24 Analysis of Effects on the Natomas Basin HCP owls using the Natomas Basin, and since the Basin accounts for a very small portion of the Central Valley’s burrowing owl population and of the habitat it occupies (USFWS 2003), the project would not alter the viability of the burrowing owl population using the Natomas Basin.
4.5 LOGGERHEAD SHRIKE
4.5.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
Loggerhead shrikes (Lanius ludovicianus) are most commonly found in grasslands, agricultural lands, open shrublands, and open woodlands (Bent 1950). Land cover types designated as shrike habitat in the NBHCP include alfalfa, grassland, non-rice crops, oak groves, orchard, pasture, ponds and seasonally wet areas, riparian, ruderal, rural residential, tree groves, and canals. Special habitat features that improve shrike abundance, survival, and reproductive success are hunting perches, low nesting trees and shrubs, thorny vegetation, and/or barbed wire on which to impale their prey. Shrikes select a variety of prey including insects, reptiles, mammals, and birds.
Home Range Size and Movement
The mean territory size of breeding loggerhead shrikes in mainland California is 22 acres (Miller 1931). The range-wide maximum and minimum breeding territory sizes recorded are 1.7 and 44 acres (Yosef and Grubb 1994). Territory size varies with habitat quality, prey abundance and availability, and density of hunting perches (Kridelbaugh 1982, Yosef and Grubb 1992). Loggerhead shrikes have been observed foraging up to a quarter mile from active nests (Brooks 1988). Shrikes are year-round residents in California, and breeding pairs disband in autumn to defend separate, adjacent, winter territories (Miller 1951, Craig 1978). As food availability decreases in winter, seasonal home ranges may increase to 128 acres (Blumton et al. 1989). Juvenile shrikes move an average of 3.4 miles from their natal territories to their fall territories.
Mechanisms of Habitat Degradation
Increased Predation
Domestic cats are a common predator of loggerhead shrike adults, juveniles and nests (Luukkonen 1987, Novak 1989), and would increase in abundance following the proposed development. Crooks and Soule (1999) quantified the impacts of domestic cat predation on songbirds such as loggerhead shrikes, and estimated that the average domestic cat population in moderately sized fragments (~50 acres of upland habitat bordered by 100 residences) returns about 525 birds to human residences each year. Assuming that cats do not bring back all prey that they kill, actual impacts to birds are probably even greater.
Many wild mammalian predators of shrikes also increase near human habitation. In proximity to residential development, dominant, larger carnivores such as coyotes are typically replaced by foxes, opossums, skunks, and other small predators that feed on shrikes and other songbirds. Crooks and Soule (1999) have recorded increased avian extirpation rates in habitat fragments as a result of these predator increases.
Shrike nest predators such as crows also typically increase in proximity to residential development, in response to introduced nesting trees, increased food supplies, and increased hunting perches such as street lights and other infrastructure (Steenhof et al. 1993; Marzluff et al. 2001). Predation of loggerhead shrike nests is also more intense along roads, urban edges, and other linear habitats (DeGeus 1990), presumably because of the increased use of linear rights-of-way by crows and mammalian predators (Knight et al. 1995). Of loggerhead shrike nest failures, 40–90% have been attributed to predation in the various studies of this species (NatureServe). Shrike
Greenbriar Development Project EDAW
City of Sacramento 4-25 Analysis of Effects on the Natomas Basin HCP mortality from vehicle collisions has also been significant in some areas (NatureServe), and may increase with increased traffic generated by the proposed residential development.
Nest Disturbance
Loggerhead shrikes will abandon nests if disturbed by humans during egg-laying or early in incubation. Shrikes are generally tolerant of human activity near nests later in the breeding season, however, and nest abandonment is not generally a significant factor in nest failure (Collister 1994).
Habitat Fragmentation
Habitat fragmentation has been implicated as a major cause of population decline in grassland birds in general, and is likely to specifically affect loggerhead shrikes. Helzer and Jelinski (1999) found both overall avian species richness and the presence of several common grassland species to increase with the size of habitat patches (especially when >50 ha) and decrease with the perimeter-area ratio of these patches, which reflects the proportion of habitat influenced by edge effects. Hinsley et al. (1995) and Crooks et al. (2001) also demonstrated the instability of upland bird populations in habitat fragments.
DISTRIBUTION
Information on CNDDB Occurrences
Although loggerhead shrikes are known to occur in open habitats throughout California (California Department of Fish and Game 1990), they have not been extensively surveyed and few occurrence data are available in the state.
The CNDDB lists five occurrences for this species, all in southern California.
Other Information on Distribution and Abundance in Natomas Basin The Natomas Basin Conservancy lists 82 shrike occurrences throughout the Basin, and suitable nesting and foraging habitat is common throughout the area. Shrikes were observed on the Greenbriar site during March 2005 surveys.
4.5.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
The project’s effects on the acreage of shrike habitat are summarized in Table 4-5. The project would reduce the acreage of loggerhead shrike habitat in the Natomas Basin from conditions at the time of the NBHCP (2001). The proposed development at the Greenbriar site would reduce habitat by an estimated 369 acres from conditions in 2001. At the proposed Spangler reserve, shrike habitat would increase by 228 acres because habitat would be created (by converting rice to marsh and upland habitat). Thus, the project as a whole would yield a net loss of 141 acres of loggerhead shrike habitat.
Effects on Quality of Habitat
Areas Adjacent to Developed Land or Highways
Although the urban area that would be created by the Greenbriar project would result in a net reduction of areas within 800 feet or 1 mile of development, the project would expand a gradient of urban influence into the previously unaffected area to the north of the property and could increase the urban influence in the idle field to
Greenbriar Development Project EDAW
City of Sacramento 4-26 Analysis of Effects on the Natomas Basin HCP the southwest. The potential affects on loggerhead shrikes in these areas are discussed under Mechanisms of Habitat Degradation, above.
Table 4-5
Change in Acreage of Loggerhead Shrike Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total Change Future Condition
with Project
Alfalfa 368 - 14.2 45.4 59.7 428
Canals 1,162 -15.0 0.0 -1.4 -16.4 1,146
Grassland 284 26.5 - - 26.5 311
Idle 422 -62.5 - - -62.5 360
Non-rice crops 9,533 -234.1 -28.4 - -262.6 9,270
Oak groves 77 - - - 0.0 77
Orchards 165 - - - 0.0 165
Pasture 494 -33.8 - - -33.8 460
Ponds & seasonally wet areas 2,259 2.7 14.2 184 200.9 2,460 Riparian 91 0.0 0.0 - 0.0 91
Ruderal 370 -9.22 - - -9.2 361
Rural residential 287 -43.319 - - -43.3 244
Tree groves 44 - 0.0 - 0.0 44
Total 15,555 -368.8 0.0 228 -140.8 15,415
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
The current land use immediately to the north of the Greenbriar site is rice and as such does not support loggerhead shrike habitat. However, the creation of shrike habitat at the Greenbriar site between 2001 and 2005 attests to the potential for the area to the north to become impacted shrike habitat in the future. The habitat creation on the Greenbriar site resulted from the conversion of a portion of the rice acreage to fallow agriculture and non-rice crops. The current land use to the southwest of the property is fallow agriculture, which supports loggerhead shrike habitat.
Adverse effects on adjacent land, though probably not insignificant, would be limited by Interstate 5 along the Greenbriar site’s southern border and by Elkhorn Boulevard (which would be expanded to six lanes) that would serve as partial barriers between development on the Greenbriar site and adjacent agricultural lands.
Altered Habitat Quality at Proposed Reserve and Mitigation Sites In addition to habitat loss due to development of the Greenbriar site and habitat creation from rice at the proposed Spangler reserve, the quality of loggerhead shrike habitat could be altered at the conserved corridor along Lone Tree Canal, the proposed Natomas 130 reserve, and the mitigation site(s) that would be required by mitigation measure 6.13-2 of the DEIR.
Conservation of the corridor along Lone Tree canal may improve its value as foraging habitat because it would be converted to perennial grassland that might have higher habitat value than the current and recent agricultural land cover. This corridor, however, would be a relatively narrow band of potential habitat surrounded by urban development, and this setting might limit its use by loggerhead shrike.
Greenbriar Development Project EDAW
City of Sacramento 4-27 Analysis of Effects on the Natomas Basin HCP At the proposed Natomas 130 reserve, there would be little overall change in habitat quality. Habitat quality would decrease on the 14 acres of created marsh, because this land cover type provides lower quality shrike habitat than the agricultural cropland it would replace. Conversely, habitat quality would increase on the 14 acres managed to provide high quality foraging habitat for Swainson’s hawk. At the Spangler site, 235 acres would be enhanced for loggerhead shrike by the conversion of rice to managed marsh and uplands. Loggerhead shrike habitat would also be enhanced at the on 49 acres at the DEIR mitigation site. Mitigation measure 6.13-2 of the DEIR requires the enhancement and preservation of at least 49 acres to provide high quality foraging habitat. This DEIR mitigation is in addition to the proposed reserves. Its management to provide high quality foraging habitat for Swainson’s hawk would also increase habitat quality for loggerhead shrike.
Overall, the project would preserve and actively manage 345 acres of habitat (30.4 acres at the Natomas 130 site, 235.4 acres at the Spangler site, 30.6 acres at the Greenbriar site, and at least 49 acres at the mitigation site required by mitigation measure 6-13.2 of the DEIR). This preservation and management would provide additional benefits (such as reduced human disturbance).
Effects on Connectivity
With the exception of the 250-foot wide proposed conservation easement along Lone Tree Canal, development at the Greenbriar site would eliminate the existing contiguity of upland habitats to the north and south of the site.
This connectivity will already be substantially reduced by development at the Metro Air Park, which would leave the Greenbriar site as the last north-south habitat corridor in the Basin east of the mile wide corridor along the Sacramento River. Shrike survival and reproduction are likely to be higher in larger, more contiguous habitat areas. Connectivity benefits shrikes by providing greater ease of locating mates, greater flexibility in year-round foraging opportunities, and safer passages for juvenile dispersal and seasonal movements. The potential effects of reduced connectivity on upland birds in general are discussed under Mechanisms of Habitat Degradation, above.
Except for the proposed Spangler reserve, the proposed reserve and mitigation sites already provide shrike habitat, and thus their preservation and management are unlikely to significantly increase habitat connectivity. The creation of habitat at the proposed Spangler reserve could locally increase connectivity of shrike habitats.
EFFECTS OF CONSTRUCTION-RELATED ACTIVITIES
Construction activities associated with the proposed development or the proposed habitat creation on proposed reserve sites could disturb or displace loggerhead shrikes and may cause nest abandonment. In the Greenbriar project DEIR and Natomas Basin HCP, preconstruction surveys for loggerhead shrikes would be conducted before construction. If shrikes are found, disturbance would be avoided during the nesting season to the maximum extent possible.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
On the remaining habitat adjacent to the proposed development, human activity may cause shrike nest abandonment or interfere with the incubation and feeding of young in a way that reduces reproductive success.
Increased shrike predation would also be likely to occur in proximity to the proposed development, as a result of the typical increase in human-associated predators discussed above under Mechanisms of Habitat Degradation.
Human-wildlife conflicts are unlikely to occur at the proposed reserve sites.
OVERALL EFFECT ON POPULATION VIABILITY
Overall, the Greenbriar project could cause a small adverse or beneficial effect on loggerhead shrike. Though it would enhance 298 acres of shrike habitat and preserve 345 acres of habitat, these beneficial effects might not fully offset the project’s adverse effects on loggerhead shrike, which include a net loss of 141 acres of habitat, reduced habitat quality on 45 acres (14 acres at Natomas 130 and 30.6 acres along Lone Tree Canal),
Greenbriar Development Project EDAW
City of Sacramento 4-28 Analysis of Effects on the Natomas Basin HCP fragmentation of habitat, a reduction of connectivity, and probably some increased mortality and habitat degradation adjacent to the Greenbriar site. However, the project’s effects would be small relative to the quantity of habitat that would remain in the Natomas Basin (e.g., the project would cause the loss of approximately 1% of habitat that would be available under the future condition), and the Natomas Basin represents only a small portion of the habitat used by shrikes in the Central Valley (USFWS 2003). Thus, the project is unlikely to alter the viability of the loggerhead shrike population using the Natomas Basin.
4.6 TRICOLORED BLACKBIRD
4.6.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
Tricolored blackbirds (Agelaius tricolor) nest in dense colonies that range from less than 25 individuals to over 80,000. As nesting and foraging habitat differ for this species, we analyzed these habitats separately. Common nesting substrates include tule and cattail marsh, blackberry, thistle, willow, nettle, and some grain crops (Beedy and Hayworth 1991). Because patches of dense nesting substrate do not necessarily correlate with the land cover types defined by the NBHCP, the NBHCP analyzed these patches separately as “tricolored blackbird nesting habitat.” Special habitat features that improve nesting blackbird abundance, survival and reproductive success include dense nesting substrates and proximity to concentrated insect populations large enough to sustain the colony (Grinnell and Miller 1944, DeHaven 2000).
Tricolored blackbirds forage in grassland, pasture, silage, wetlands and flooded fields, rice, and other grain fields (Zeiner et al. 1990). Land cover types designated as tricolored blackbird foraging habitat in the NBHCP include alfalfa, grassland, non-rice crops, pasture, and rice. As they represent a transition between cropland and grassland habitats, idle and ruderal fields may also provide marginal foraging habitat. Tricolored blackbirds are primarily insectivorous, with grasshoppers, beetles, and weevils dominating their diet (Beedy and Hayworth 1991).
Home Range Size and Movement
Breeding tricolored blackbirds concentrate foraging activity in proximity to nesting colonies, and may travel up to 4 miles from nest or roost sites to forage. The species is generally nomadic when not breeding, and may be found year-round throughout lowland California.
Mechanisms of Habitat Degradation
Increased Predation
Abundance of blackbird predators such as domestic cats and foxes typically increases in proximity to residential development (Crooks and Soule 1999). Although increased predation near residential development would likely be much less for vigilant, mobile flocks of foraging blackbirds than for more stationary nesting birds such as loggerhead shrikes or burrowing owls, predation rates would be expected to increase for all small bird species near residential development.
Nest Disturbance
Nesting colonies of tricolored blackbirds are highly sensitive to disturbance, which may cause nest abandonment or interfere with the incubation and feeding of young in a way that reduces reproductive success (NBHCP 2001).
Greenbriar Development Project EDAW
City of Sacramento 4-29 Analysis of Effects on the Natomas Basin HCP Water Diversion and Runoff
Water diversions may degrade wetland habitat for tricolored blackbirds nesting downstream from a diversion.
DISTRIBUTION
Information on CNDDB Occurrences
The NBHCP does not list state-wide or Basin-specific CNDDB occurrences of tricolored blackbirds, but notes 9 occurrences in Sutter County, 7 of which were extant in 2001. As of 2005, there are 408 known occurrences in California, of which 339 are considered extant. At this time, CNDDB does not list tricolored blackbird occurrences within one mile of the Natomas Basin.
Other Information on Distribution and Abundance in Natomas Basin At the time of the NBHCP in 2001, the Betts-Kismat-Silva reserve on the eastern edge of the Natomas Basin supported a tricolored blackbird colony of approximately 4,000 nesting birds (NBHCP 2001). At the time of the most recent TNBC monitoring report in 2004, the blackbirds did not nest at this site, although 125–300 birds were regularly seen in the area. Tricolored blackbirds similarly did not nest at this site in 2005 (unpublished data).
Tricolored blackbirds are known to forage throughout the Basin (NBHCP), and have been observed foraging on the Metro Air Park site near the Greenbriar site (Thomas Reid Associates, 2000).
4.6.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
The Project’s effects on the acreage of nesting habitat for tricolored blackbirds are summarized in Table 4-6. The Greenbriar and proposed reserve sites do not currently support tricolored blackbird nesting habitat. The proposed creation of 198 acres of marsh at the Natomas 130 and Spangler sites would provide potential nesting habitat in these managed marshes. However, at the Natomas 130 site, because of the extensive urban development nearby and variety of habitats surrounding the parcel, it is unclear whether the foraging habitat surrounding the created marsh would be adequate to sustain a nesting colony of blackbirds. This is not the case at the Spangler site where most of the marsh (184 of 198 acres) would be created.
Table 4-6
Change in Acreage of Tricolored Blackbird Nesting Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total Change Future Condition
with Project
Ponds & seasonally wet areas 2,259 2.7 14.2 184.0 200.9 2,460 Total 2,259 2.7 14.2 184.0 200.9 2,460
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
The Project’s effects on the acreage foraging habitat for tricolored blackbirds are summarized in Table 4-7. The project would reduce the acreage of tricolored blackbird foraging habitat in the Natomas Basin. The proposed development at the Greenbriar site would eliminate an estimated 402 acres of habitat, based on 2001 land cover.
Greenbriar Development Project EDAW
City of Sacramento 4-30 Analysis of Effects on the Natomas Basin HCP At the proposed Spangler and Natomas 130 reserves, 197 acres of foraging habitat would be eliminated (by conversion of rice and non-rice crop to marsh). Thus, the project as a whole would yield a net loss of 598 acres of tricolored blackbird foraging habitat.
Table 4-7
Change in Acreage of Tricolored Blackbird Foraging Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total Change Future Condition
with Project
Alfalfa 368 - 14.2 45.4 59.6 428
Grassland 284 26.5 - - 26.5 311
Non-rice crops 9,533 -234.1 -28.4 - -262.6 9,270
Pasture 494 -33.8 - - -33.8 460
Rice 11,643 -160.0 - -228 -388.0 11,255
Total 22,322 -401.5 -14.2 -182.6 -598.3 21,724
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
Effects on Quality of Habitat
Areas Adjacent to Developed Land or Highways
Although the urban area that would be created by the proposed Greenbriar development would result in a net reduction of areas within 800 feet or 1 mile of development, the project would expand a gradient of urban influence into the previously unaffected area to the north of the property and increase the urban influence in the idle field to the southwest. The potential effects in this area on tricolored blackbirds are discussed under Mechanisms of Habitat Degradation, above. These effects include increased predation of foraging tricolored blackbirds but not of nesting blackbirds. Tricolored blackbird nesting habitat does not currently exist in the vicinity of the Greenbriar site; therefore, the project would not result in nest disturbance unless new nests were established near the site.
The current land use to the north of the Greenbriar site is rice, which provides tricolored blackbird foraging habitat. The current land use to the southwest of the property is fallow agriculture, which does not support quality blackbird habitat. However, the conversion of rice to non-rice crops at the Greenbriar site between 2001 and 2005 attests to the potential for agricultural habitats to change; the area to the southwest may thus become blackbird foraging habitat in the future (and conversely, foraging habitat to the north could become less suitable).
Adverse effects on adjacent land, though probably not insignificant, would be limited by Interstate 5 along the Greenbriar site’s southern border and by Elkhorn Boulevard (which would be expanded to six lanes) along the site’s northern border, which would serve as partial barriers between development on the Greenbriar site and adjacent agricultural lands.
Habitat Alteration at Proposed Reserve and Mitigation Sites The project would preserve approximately 198 acres of nesting habitat (14 acres at the Natomas 130 site and 184 acres at the Spangler site). (The 2.7 acres of marsh created at the Greenbriar site was not considered suitable as nesting habitat because of its small size and surrounding urban development.) In addition to its other benefits, preservation should reduce the level of human disturbance, which could enhance the quality of nesting habitat.
Greenbriar Development Project EDAW
City of Sacramento 4-31 Analysis of Effects on the Natomas Basin HCP The project with the DEIR mitigation would preserve at least 135 acres of foraging habitat: 14 acres at the Natomas 130 site, 45 acres at the Spangler site, 27 acres at the Greenbriar site, and at least an additional 49 acres required by mitigation measure 6-13.2 of the DEIR. (The Spangler site is within foraging distance of the TNBC Betts-Kismat-Silva reserve where tricolored blackbirds have nested.) At the Natomas 130, Spangler, and DEIR mitigation sites, management of 109 acres to provide high quality foraging habitat for Swainson’s hawk would also enhance habitat values for tricolored blackbird; however, because the benefits of such management for tricolored blackbirds have not been documented, a moderate level of uncertainty exists regarding their magnitude. (The preservation of land along Lone Tree Canal and its conversion to grassland was not considered an enhancement of foraging habitat because this site would also be affected by the proposed development.) Effects on Connectivity
Because tricolored blackbirds are largely nomadic when not nesting, connectivity for this species is mostly pertinent to a 4-mile radius of foraging habitat surrounding nesting colonies. The Greenbriar site is at the edge of this radius from the TNBC Betts-Kismat-Silva reserve where tricolored blackbirds have nested, and thus development at the Greenbriar site would not affect connectivity of foraging habitat near this reserve (although it would reduce the habitat acreage within 4 miles of the reserve). The proposed Spangler reserve is similarly located along the edge of this radius and would preserve foraging habitat within 4 miles of the TNBC Betts- Kismat-Silva reserve (but would not affect connectivity). The proposed Natomas 130 reserve is located outside of this 4-mile radius. The land that would be preserved to provide Swainson’s hawk foraging habitat also might increase connectivity of tricolored blackbird habitat depending on its location, but the location of this mitigation land has not yet been specified.
EFFECTS OF CONSTRUCTION-RELATED ACTIVITIES
Construction-related activities are unlikely to affect tricolored blackbirds because they do not nest in the vicinity of the Greenbriar and proposed reserve sites. Potential effects would be limited to displacement of birds foraging or roosting on the sites during the initial phases of construction when fields are graded. This impact is largely akin to habitat loss, as the physical flight of the birds from these areas would not cause a significant effect.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
Because tricolored blackbirds do not currently nest in the vicinity of the proposed development or reserve sites, nest disturbance by humans would not be created by the project. Increased populations of human-associated predators may result in increased predation of foraging blackbirds near a developed Greenbriar site, as discussed in Mechanisms of Habitat Degradation, above.
OVERALL EFFECT ON POPULATION VIABILITY
There is a moderate level of uncertainty regarding the overall effect of the Greenbriar project on tricolored blackbird because of the limited current use of the Natomas Basin by tricolored blackbird, opposite effects on nesting and foraging habitat, and uncertainty regarding the benefits provided by foraging habitat enhancement.
Recently, only a single colony of tricolored blackbirds has nested in the Natomas Basin (Jones & Stokes 200).
However, substantial quantities of foraging habitat (over 21,000 acres, Table 3-3) and an increasing acreage of nesting habitat exist in the Basin, and thus tricolored blackbird use of the Basin could increase. The Greenbriar project would increase the quantity of nesting habitat in the Natomas Basin (by 198 acres), but would decrease the quantity of foraging habitat (by 598 acres). Although currently, nesting habitat is more limited than foraging habitat in the Natomas Basin, under the future condition much more nesting habitat will exist, and thus the additional nesting habitat that would be provided by the project may not affect the tricolored blackbird population more than the loss of foraging habitat that would also result. This loss of foraging habitat would be partially but not fully offset by the preservation of 135 acres of foraging habitat and enhancement of 109 of these 135 acres.
However, the magnitude of the benefits provided by this enhancement is moderately uncertain. Because of these
Greenbriar Development Project EDAW
City of Sacramento 4-32 Analysis of Effects on the Natomas Basin HCP uncertainties, overall, the project could cause a small adverse or beneficial effect on tricolored blackbird use of the Natomas Basin.
Because the project would only cause a small effect on tricolored blackbird use of the Natomas Basin, and because the Natomas Basin accounts for only a small portion of the habitat for and population of tricolored blackbird in the Central Valley, the Greenbriar project is unlikely to alter the viability of the tricolored blackbird population using the Natomas Basin.
4.7 WHITE-FACED IBIS
4.7.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
White-faced ibis (Plegadis chihi) breed in wetlands with dense emergent vegetation such as cattails and rushes.
They forage in shallow wetlands, irrigation ditches and a variety of irrigated crops and flooded agricultural fields (Ryder and Manry 1994, Cogswell 1977). Land cover types designated as ibis habitat in the NBHCP include alfalfa, canals, ponds and seasonally wet areas, and rice. White-faced ibis feed on aquatic and moist-soil invertebrates such as earthworms, larval insects, snails, and bivalves. Although white-faced ibis feed intensively in rice fields, rice seeds have not been noted in food samples and only trace, incidental amounts of vegetation have been recorded in ibis diets (Belknap 1957).
Home Range Size and Movement
Nesting colonies have ranged in size from 1.3 acres to 600 acres (USFWS 1985e). Foraging distances from nesting sites vary widely and depend on the availability of food. Some colonies concentrate their foraging activity within 2–4 miles of their breeding sites (Bray 1986, Bray and Klebenow 1988), while others forage 25–30 miles from nest sites (Trost 1989). Some colony locations are used for nesting year after year, while others are used more sporadically depending on water conditions and the availability of food (Ryder 1967).
Mechanisms of Habitat Degradation
Water Quality and Water Diversion
White-faced ibis depend on healthy populations of aquatic invertebrate prey, which in turn may be greatly affected by surrounding land use. Urban areas can cause different and in some cases stronger effects than agricultural lands (Bury 1972, Moore and Palmer 2005). Residential developments typically result in increased runoff of hydrocarbons and of chemicals used for lawns and gardens, and increased stormwater volume (and associated increased depths and velocities) because of high coverage of impervious surfaces. Water diversions may also reduce the abundance of ibis prey. Decreased abundance of aquatic invertebrates has been shown to impact insectivorous birds in both observational field studies and controlled field experiments (Baxter et al. 2004, in press and in review).
DISTRIBUTION
Information on CNDDB Occurrences
When information was compiled for the NBHCP in 2001, there were seven known breeding colonies in California, all of which were considered extant. At that time, no colonies were known in the Natomas Basin, and the nearest known nesting occurrence was in Yolo County, north of Woodland. As of 2005, there are 15 known
Greenbriar Development Project EDAW
City of Sacramento 4-33 Analysis of Effects on the Natomas Basin HCP occurrences in California, of which 13 are considered extant. At this time, CNDDB does not list white-faced ibis occurrences within one mile of the Natomas Basin.
Other Information on Distribution and Abundance in Natomas Basin White-faced ibis are common winter foragers in the Natomas Basin (NBHCP), and 10,000 to 11,000 ibis have been estimated in the Sacramento Valley as a whole (Hickey and Shufford 1996, Thomas Reid Associates 2000).
4.7.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
Neither the Greenbriar site nor the proposed reserves currently support potential nesting habitat for white-faced ibis. However, the proposed creation of 198 acres of marsh at the Natomas 130 and Spangler sites could provide nesting habitat. (The 2.7 acres of marsh proposed along Lone Tree Canal was not considered suitable nesting habitat because of its small size and the surrounding urban development.) Thus, the project could increase white- faced ibis nesting habitat in the Natomas Basin by up to 198 acres from conditions at the time of the NBHCP (2001).
The project’s effects on the acreage of white-faced ibis foraging habitat are summarized in Table 4-8. The project would reduce the acreage of white-faced ibis foraging habitat in the Natomas Basin from conditions at the time of the NBHCP (2001). The proposed development at the Greenbriar site would reduce habitat by an estimated 172 acres from conditions in 2001. At the proposed Natomas 130 reserve, 28 acres of white-faced ibis habitat would be created from non-habitat (by converting 28 acres of non-rice crop to 14 acres of marsh and 14 acres of alfalfa).
Thus, the project as a whole would yield a net loss of 144 acres of white-faced ibis habitat. (This total change does not include habitat at the mitigation site required by mitigation measure 6-13.2 of the DEIR for Swainson’s hawk foraging habitat because the existing land cover type of that site is not known.) Table 4-8
Change in Acreage of White-faced Ibis Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total Change Future Condition
with Project
Alfalfa 368 - 14.2 45.4 59.6 428
Canals 1,162 -15.0 0.0 -1.4 -16.4 1,146
Ponds & seasonally wet areas 2,259 2.7 14.2 184 200.9 2,460 Rice 11,643 -160.0 - -228 -388.0 11,255
Total 15,432 -172.4 28.4 0 -143.9 15,288
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
Effects on Quality of Habitat
Areas Adjacent to Developed Land or Highways
Potential impacts to white-faced ibis that forage near developed areas are discussed under Mechanisms of Habitat Degradation, above. They are primarily associated with canal and wetland habitats, but also forage in rice, and these habitats exist near the Greenbriar site.
Greenbriar Development Project EDAW
City of Sacramento 4-34 Analysis of Effects on the Natomas Basin HCP Habitat Alteration at Proposed Reserves and Mitigation Sites A total of 316 acres of white-faced ibis habitat would be preserved. Of this preserved habitat, 190 acres (184 acres of rice and 6 acres of associated canals) would be enhanced by the conversion of rice to marsh at the proposed Spangler reserve. In addition, habitat values for white-faced ibis might be improved by habitat enhancement for Swainson’s hawk at the proposed Natomas 130 and Spangler reserves (60 acres) and at the DEIR mitigation site (at least 49 acres to satisfy mitigation measure 6.13-2 of the DEIR).
Effects on Connectivity
Habitat connectivity is of lesser importance to foraging ibis than to nesting or less mobile animals. Ibis survival is likely to be higher, however, in larger, more contiguous foraging habitat where prey is more abundant and the energetic costs of travel are decreased.
EFFECTS OF CONSTRUCTION-RELATED ACTIVITIES
Construction-related activities are unlikely to affect white-faced ibis because they do not nest in the vicinity of the Greenbriar and proposed reserve sites. Potential effects would be limited to displacement of birds foraging or roosting on the sites during the initial phases of construction when fields are graded. This would be largely akin to habitat loss, as the physical flight of the birds from these areas would not cause a significant effect.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
Humans entering active colonies may cause partial or total desertion of the colony, particularly during nest-site selection, nest-building, and incubation (Ryder and Manry 1994). Because white-faced ibis do not currently nest in the Basin, the project is unlikely to affect human conflicts with this species. (Foraging ibis are less sensitive to disturbance than nesting birds.) Similarly, changes in predator communities associated with residential development would be unlikely to affect large ibis as much as smaller birds such as burrowing owls and loggerhead shrikes.
OVERALL EFFECT ON POPULATION VIABILITY
The Greenbriar project is not likely to affect the viability of the white-faced ibis population using the Natomas Basin. Currently, white-faced ibis uses the Natomas Basin only for winter foraging. The Greenbriar project would reduce the area of foraging habitat in the Natomas Basin (by 1%), and would at least partially offset this effect by preserving and enhancing 2% of foraging habitat in the Natomas Basin. The abundance of white-faced ibis, however, is not considered limited by the availability of winter foraging habitat, and the Greenbriar project would not substantially alter the quantity of winter foraging habitat in the Natomas Basin; thus, the project’s effect on foraging habitat is not likely to alter the population viability of white-faced ibis. The project would also increase the acreage of nesting habitat by creating marsh, and this could lead to the establishment of a white-faced ibis nesting colony in the Natomas Basin. While not discounted, this effect was not considered likely.
4.8 ALEUTIAN CANADA GOOSE
4.8.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
Aleutian Canada geese (Branta canadensis leucopareia) winter in California’s central valley. They forage primarily in pasture, corn, wheat, rice and other grain crops, wetlands, and grasslands, and typically prefer short
Greenbriar Development Project EDAW
City of Sacramento 4-35 Analysis of Effects on the Natomas Basin HCP vegetation. Wintering geese roost in large ponds and lakes, flooded fields, and rice checks. Land cover types designated as Aleutian Canada goose habitat in the NBHCP include non-rice crops, pasture, and rice. While Aleutian Canada geese feed primarily on grasses and wetland sedges during their Alaskan summer, they forage primarily on seeds and agricultural grains while in California in fall and winter (NatureServe 2005).
Home Range Size and Movement
Aleutian Canada geese nest in the western Aleutian Islands and migrate through coastal Oregon and northern California after the breeding season. Most wintering Aleutian Canada geese concentrate in the Modesto, Los Banos, and Colusa areas of California; the Natomas Basin may provide important foraging and roosting habitat during goose migration.
Mechanisms of Habitat Degradation
Because Canada geese are particularly well-adapted to foraging in agricultural landscapes and may persist in small numbers in suburban parks, habitat loss is a greater issue for this species than habitat degradation. This species is similarly not dependent on animal prey populations or sensitive to the increases in small mammalian or corvid predators that typically occur near residential developments.
DISTRIBUTION
Information on CNDDB Occurrences
When information was compiled for the NBHCP in 2001, there were 13 known occurrences in California, all of which were considered extant. At that time, no occurrences were known from the Natomas Basin. As of 2005, there are 10 known occurrences in California, all of which are considered extant. At this time, CNDDB does not list Aleutian Canada goose occurrences within one mile of the Natomas Basin.
Other Information on Distribution and Abundance in Natomas Basin Although Aleutian Canada geese have not been recorded in the Basin, its proximity to important wintering areas suggests that they are likely to forage and roost in the Basin during migration.
4.8.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
The project’s effects on the acreage of Aleutian Canada goose habitat are summarized in Table 4-9. The project would reduce the acreage of Aleutian Canada goose habitat in the Natomas Basin from conditions at the time of the NBHCP (2001). The proposed development at the Greenbriar site would reduce habitat by an estimated 428 acres from conditions in 2001. At the proposed Spangler and Natomas 130 reserves, an additional 256 acres of goose habitat would be eliminated (by converting rice and non-rice crop to marsh). Thus, the project as a whole would yield a net loss of 684 acres of Aleutian Canada goose habitat.
Greenbriar Development Project EDAW
City of Sacramento 4-36 Analysis of Effects on the Natomas Basin HCP Table 4-9
Change in Acreage of Aleutian Canada Goose Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total Change Future Condition
with Project
Non-rice crops 9,533 -234.1 -28.4 - -262.6 9,270
Pasture 494 -33.8 - - -33.8 460
Rice 11,643 -160.0 - -228 -388.0 11,255
Total 21,670 -428.0 -28.4 -228 -684.4 20,986
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
Effects on Quality of Habitat
Areas Adjacent Developed Land or Highways
As discussed above under Mechanisms of Habitat Degradation, the predominant impacts typically associated with areas adjacent to housing developments are unlikely to adversely affect Canada geese. This species is especially well-adapted to foraging in close proximity to humans.
Habitat Alteration at Proposed Reserve and Mitigation Sites Aleutian goose habitat probably would not be preserved or enhanced at the proposed reserve and DEIR mitigation sites. However, the 109 acres that would be actively managed to provide high quality foraging habitat for Swainson’s hawk (at the proposed reserve and DEIR mitigation sties) might provide goose habitat values.
Effects on Connectivity
Habitat connectivity is of lesser importance to foraging geese than to nesting or less mobile animals. Goose survival is likely to be higher, however, in larger, more contiguous foraging habitat where food is more abundant and the energetic costs of travel are decreased.
EFFECTS OF CONSTRUCTION-RELATED ACTIVITIES
Construction-related activities are unlikely to affect Aleutian Canada geese because they do not nest in the vicinity of the Greenbriar and proposed reserve sites. Potential effects would be limited to displacement of birds foraging or roosting on the sites during the initial phases of construction when fields are graded. This effect is largely akin to temporary habitat loss.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
Because Aleutian Canada geese do not nest in the Basin, the project would not likely result in human conflicts with this species, other than the changes in habitat. Foraging geese are less sensitive to disturbance than nesting birds. Similarly, changes in predator communities associated with residential development would be unlikely to affect large geese as significantly as smaller birds such as burrowing owls and loggerhead shrikes.
OVERALL EFFECT ON POPULATION VIABILITY
Currently, Aleutian Canada geese do not nest in the Natomas Basin, but do roost and forage in the Basin during seasonal migration to a limited extent. Although the Greenbriar Project would reduce the acreage of foraging
Greenbriar Development Project EDAW
City of Sacramento 4-37 Analysis of Effects on the Natomas Basin HCP habitat in the Natomas Basin (by 3%), an effect on the population’s viability is unlikely because the population’s size is not considered to be limited by the quantity of foraging habitat available during migration and the Greenbriar project would not substantially alter the availability of this habitat, which is abundant in the Natomas Basin (approximately 21,000 acres).
4.9 BANK SWALLOW
4.9.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
Bank swallows (Riparia riparia) nest in colonies in vertical banks, cliffs and bluffs that are typically along streams but occasionally near roads or gravel quarries. Nesting colonies may range in size from 10 to 1,500 pairs, and average 100–200 nesting pairs (NBHCP). Bank swallows forage in a variety of open habitats including wetlands, open water, grasslands, agricultural fields, shrublands, and open or riparian woodlands. Aquatic and flooded habitats provide the best foraging opportunities. Land cover types designated as bank swallow habitat in the NBHCP include alfalfa, canals, grassland, non-rice crops, pasture, ponds and seasonally wet areas, rice, and riparian. Swallows are almost exclusively insectivorous and catch their prey while flying.
Home Range Size and Movement
Most breeding season foraging flights are within a kilometer (0.62 mile) of the nesting colony (Garrison 1999).
Bank swallows are long-distance migrants and may use any available foraging habitat in the Basin during migration.
Mechanisms of Habitat Degradation
Bank Erosion and Water Diversion
The major contributors to bank swallow habitat degradation are flood and erosion control projects that apply riprap or reduce the slope of river banks and canals, rendering them unusable for nesting and reducing their habitat quality for roosting and foraging (Garrison et al. 1987, Small 1994). Diversion of water may affect bank swallows if it results in the dewatering of canals or reduction of aquatic habitat for larval insects.
Water Quality and Runoff
Aquatic communities may be greatly affected by surrounding land use. Urban areas can cause different and in some cases stronger effects than agricultural lands (Bury 1972, Moore and Palmer 2005). Residential developments typically result in increased runoff of hydrocarbons and of chemicals used for lawns and gardens, and increased stormwater volume (and associated increases in depths and velocities) because of high coverage of impervious surfaces. Decreased abundance of aquatic invertebrates has been shown to impact insectivorous birds in both observational field studies and controlled field experiments (Baxter et al. 2004, in press and in review).
Predation and Nest Disturbance
Although predation of most birds increases in proximity to human settlement, bank swallows are largely protected from human-associated predators because of the cliff locations of their nests. These aerial hunters are also largely protected from human-associated predators while foraging because they spend relatively very little time foraging from perches or among vegetation. Kestrels are the primary predators of this species while foraging; snakes are
Greenbriar Development Project EDAW
City of Sacramento 4-38 Analysis of Effects on the Natomas Basin HCP most common while nesting. Bank swallows are typically tolerant of human activity near nesting colonies, if humans do not attempt to climb the nest banks (Garrison 1999).
DISTRIBUTION
Information on CNDDB Occurrences
When information was compiled for the NBHCP in 2001, there were 171 known occurrences in California, of which 170 were considered extant. At that time, no nesting colonies were known in the Natomas Basin. As of 2005, there are 176 known occurrences in California, of which 171 are considered extant. At this time, CNDDB does not list bank swallow occurrences within one mile of the Natomas Basin.
Other Information on Distribution and Abundance in Natomas Basin Although no nesting colonies are known in the Basin, the area provides potential foraging habitat for migrating swallows.
4.9.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
The project would not affect bank swallow nesting habitat, as bank swallow nesting colonies do not exist at the Greenbriar or proposed reserve sites, nor would nesting habitat be created, enhanced or preserved at the proposed reserves.
The project’s effects on the acreage of bank swallow foraging habitat are summarized in Table 4-10. The project would reduce the acreage of bank swallow foraging habitat in the Natomas Basin from conditions at the time of the NBHCP (2001). The proposed development at the Greenbriar site would reduce habitat by an estimated 414 acres from conditions in 2001. At the proposed Natomas 130 and Spangler reserves, habitat acreages would be increased by about 20 acres. Thus, the project as a whole would yield a net loss of 394 acres of bank swallow habitat.
Table 4-10
Change in Acreage of Bank Swallow Habitat at Project Sites and in the Natomas Basin Change at Each Project Site Land Cover Type
Providing Habitat
Future
Condition Greenbriar Natomas 130 Spangler
Total Change Future Condition
with Project
Alfalfa 368 - 14.2 45.4 59.6 428
Canals 1,162 -15.0 0.0 -1.4 -16.4 1,146
Grassland 284 26.5 - - 26.5 311
Non-rice crops 9,533 -234.1 -28.4 - -262.6 9,270
Pasture 494 -33.8 - - -33.8 460
Ponds & seasonally wet areas 2,259 2.7 14.2 184.0 200.9 2,460 Rice 11,643 -160.0 - -228.0 -388.0 11,255
Riparian 91 0.0 0.0 - 0.0 91
Total 25,834 -413.8 0.0 20.2 -393.6 25,420
Note: Acreages are based on 2001 land cover mapping used to evaluate future condition resulting from the NBHCP and future land cover proposed at project sites.
Greenbriar Development Project EDAW
City of Sacramento 4-39 Analysis of Effects on the Natomas Basin HCP Effects on Quality of Habitat
Areas Adjacent to Developed Land or Highways
As discussed above under Mechanisms of Habitat Degradation, the predominant effects typically associated with areas adjacent to housing developments are unlikely to negatively affect bank swallows. Effects on water quality and canal management, however, could potentially affect bank swallows.
Habitat Alteration at Proposed Reserve and Mitigation Sites At least 345 acres of bank swallow habitat would be preserved and enhanced at the proposed reserves and at the mitigation site required by mitigation measure 6.13-2 of the DEIR. At the Spangler site, rice habitat would be converted to marsh, preserved, and managed to provide habitat values, in particular for giant garter snake. At the Spangler site, rice would also be converted to upland habitat. This upland habitat, as well as upland habitat at the Natomas 130 and the DEIR mitigation site, would be managed to provide high quality foraging habitat for Swainson’s hawk. At all of these sites, habitat values for bank swallow are likely to increase as a result of the proposed management. However, because the benefits of such management for bank swallows have not been documented, a moderate level of uncertainty exists regarding their magnitude.
Effects on Connectivity
Because bank swallows do not nest in the Basin, connectivity is of less concern for this species than for less mobile species or species with limited foraging distances from breeding sites. Larger patches of more contiguous habitat are likely to be of greater value to migrating swallows, by providing more abundant food with the lower energetic cost of foraging in a contiguous area.
EFFECTS OF CONSTRUCTION-RELATED ACTIVITIES
Construction-related activities are unlikely to affect bank swallows because they do not nest in the vicinity of the Greenbriar and proposed reserve sites. Potential effects would be limited to displacement of birds foraging or roosting on the sites during the initial phases of construction when fields are graded. This impact is largely akin to temporary habitat loss.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
Direct human-wildlife conflicts are unlikely to be of concern for bank swallows in the Natomas Basin. Habitat quantity and quality are the primary concerns for this species.
OVERALL EFFECT ON POPULATION VIABILITY
Although the Greenbriar project would affect land suitable for bank swallow foraging (eliminating 394 acres and preserving and enhancing 345 acres), none of these lands are near (i.e., within a mile) bank swallow nesting habitat. Currently, bank swallows are not nesting near the Natomas Basin. Near the Natomas Basin, most of the bank length of the Sacramento River is not suitable for bank swallow nesting, in part because of extensive riprap (USFWS 2003). Even if bank swallow colonies established along the Sacramento River in the future, the project and mitigation sites are not within a mile of the river, and thus would not provide important foraging habitat for colonies along the river. Although these lands may provide foraging habitat to migrating swallows, habitat availability during migration is not considered to limit the abundance of this population, and large areas of such habitat (over 25,000 acres) would remain in the future condition of the Natomas Basin with the Greenbriar project. Therefore, the Greenbriar project is unlikely to alter the viability of bank swallow populations using the Natomas Basin.
Greenbriar Development Project EDAW
City of Sacramento 4-40 Analysis of Effects on the Natomas Basin HCP
4.10 VALLEY ELDERBER RY LONGHORN BEETLE
4.10.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
Valley elderberry longhorn beetles (Desmocerus californicus dimorphus) are dependent on elderberry bushes, which primarily occur in riparian areas. Small elderberry patches are also found in some oak groves and rural residential areas (NBHCP). The NBHCP lists riparian as the only land cover type that provides habitat for this species.
Home Range Size and Movement
Dispersal of valley elderberry longhorn beetles is extremely limited. Many adults live their entire lives on their original host plants and do not disperse at all. Dispersing individuals typically limit travel in their home drainages, limiting the ability of the species to colonize fragmented habitat (Collinge et al. 2001).
Mechanisms of Habitat Degradation
Elderberry habitat is degraded by fragmentation, pesticide and herbicide use, exotic species invasion, and hydrological alteration such as flood management, channel maintenance, and increased water diversions for urban and agricultural development (USFWS 1984; Huxel 2000; Collinge et al. 2001).
DISTRIBUTION
Information on CNDDB Occurrences
When information was compiled for the NBHCP in 2001, there were 168 known occurrences in California, all of which were considered extant. At that time, “several” occurrences were known along the southern and western edges of the Natomas Basin, along the American and Sacramento rivers. As of 2005, there are 190 known occurrences in California, all of which are considered extant. At this time, two occurrences are known in the Natomas Basin and six additional occurrences are known within a mile of the Basin. All eight of these occurrences are considered extant. CNDDB does not list valley elderberry longhorn beetle occurrences within one mile of the Greenbriar site; CNDDB lists one VELB occurrence within one mile of a proposed reserve.
Other Information on Distribution and Abundance in Natomas Basin The TNBC Biological Effectiveness Monitoring report concurs with the CNDDB to list eight extant VELB occurrences in the Basin, none of which are within a mile of the Greenbriar site, and one of which is within a mile of a proposed reserve.
4.10.2 P ROJECT EFFECTS ON SPECIES
LONG-TERM EFFECTS ON HABITAT
Effect on Quantity of Habitat
The project will not affect the quantity of elderberry habitat available to the beetle, as elderberry shrubs are not present in the vicinity of the Greenbriar or proposed reserve sites.
Greenbriar Development Project EDAW
City of Sacramento 4-41 Analysis of Effects on the Natomas Basin HCP Effects on Quality of Habitat
Areas Adjacent to Developed Land or Highways
As no elderberry shrubs exist in proximity to the Greenbriar site, the gradient of urban influence within 800 feet of the Greenbriar site will not affect the quality of VELB habitat.
Enhancement at Reserves
The planting of elderberry shrubs is not currently planned at the proposed reserves. However, an acre of riparian habitat exists on the Natomas 130 parcel and may be suitable for shrub planting in the future.
Effects on Connectivity
Because of the beetle’s limited dispersal capability, habitat connectivity is critical for the colonization of unoccupied shrubs and the maintenance of genetic diversity. However, because all of the Basin’s known VELB occurrences are located in riparian habitat near the Sacramento River, the project would not affect connectivity for this species. The proposed Natomas 130 reserve is located along the Sacramento River and would contribute to the preservation of contiguous riparian habitat along the river corridor.
EFFECTS OF CONSTRUCTION-RELATED ACTIVITIES
Construction-related activities for the project are unlikely to affect this species because its habitat does not exist at the Greenbriar and Spangler sites and may not be present at the Natomas 130 site. To avoid and minimize any potential impacts at the Natomas 130 site, preconstruction surveys for elderberry shrubs would be conducted according to USFWS guidelines (USFWS 1999b). If elderberry shrubs are found, they would be preserved on site unless their preservation would significantly inhibit other habitat restoration objectives on site. Following USFWS guidelines, elderberry shrubs would be avoided during habitat construction with a 100-foot construction buffer. If avoidance is not possible, shrub loss would be mitigated by transplanting the shrubs during their dormant season and planting a specified number of seedlings.
EFFECTS OF HUMAN-WILDLIFE CONFLICTS
Human-wildlife conflicts for this species would not be affected by the project because elderberry habitat does not exist on site. Although VELB and elderberry shrubs are not known to be present on the proposed reserves, preservation of the Natomas 130 parcel may reduce human conflicts with habitat in the Sacramento River riparian corridor.
OVERALL EFFECT ON POPULATION VIABILITY
VELB is not known from the vicinity of the Greenbriar site or the proposed reserve sites. A small area of riparian vegetation, which is potentially suitable habitat for this species, exists at the Natomas 130, and would be preserved by the project. It is not known if elderberry bushes are present in this riparian vegetation, and the draft restoration plan does not include the planting of elderberry bushes. Thus, the preservation of this riparian vegetation would be a very small potential benefit to VELB that would not be sufficient to alter its population viability.
Greenbriar Development Project EDAW
City of Sacramento 4-42 Analysis of Effects on the Natomas Basin HCP
4.11 CALIFORNIA TIGER SALAMANDER
4.11.1 S PECIES ECOLOGY
HABITAT ASSOCIATIONS/REQUIREMENTS
Habitat Type
California tiger salamanders (Ambystoma californiense) require two major habitat components: aquatic breeding sites and terrestrial aestivation or refuge sites. Tiger salamanders breed primarily in vernal pools and other ephemeral rainwater ponds (Loredo et al. 1996). They will occasionally breed in stockponds, reservoirs and small lakes, but fail to reproduce in water bodies that support predatory fish or bullfrogs (Stebbins 1972, Zeiner et al. 1988). The highest quality breeding habitat for tiger salamanders exists in large, contiguous vernal pool complexes in a grassland matrix with pools that last for more than 10 weeks (Jennings and Hayes 1994).
California tiger salamanders spend the majority of their lives in upland habitats within one mile (1.6 km) of aquatic breeding areas (Center for Biological Diversity 2001). These upland habitats are essential for salamander foraging, aestivation, migration, and dispersal. Upland habitats used by migrating salamanders include grassland, pasture, and open woodlands. The NBHCP lists ponds and seasonally wet areas as the only land cover type providing tiger salamander habitat because these upland habitats will only be used by salamanders when in close proximity to aquatic breeding areas. Tiger salamanders depend on burrows of small mammals such as California ground squirrels and Botta’s pocket gopher for shelter during aestivation.
Home Range Size and Movement
California tiger salamanders typically range within 2,200 feet (0.7 km) of breeding habitat during the breeding season (Trenham and Shaffer). During migration, however, they have been recorded as far as one mile (1.6 km) from aquatic habitats (Center for Biological Diversity 2001).
Mechanisms of Habitat Degradation
Tiger salamander habitat is frequently degraded by roads, buildings, and other barriers to migration (Shaffer and Fisher 1991; Shaffer and Stanley 1992; Barry and Shaffer 1994). Erosion because of grading for nearby developments can degrade breeding wetlands by increasing sedimentation. Tiger salamanders are also sensitive to pesticides, herbicides and fertilizers associated with suburban lawn care and agriculture. Burrowing mammal control programs and the introduction of predatory bullfrogs and nonnative fishes have also contributed to declines in tiger salamander populations (Jennings and Hayes 1994).
DISTRIBUTION
Information on CNDDB Occurrences
When information was compiled for the NBHCP in 2001, there were 465 known occurrences in California, all of which were considered extant. At that time, no occurrences were known from the Natomas Basin. As of 2005, there are 793 known occurrences in California, of which 738 are considered extant. At this time, CNDDB does not list California tiger salamander occurrences within one mile of the Natomas Basin.