Rincon Consultants, Inc.
2215 Faraday Avenue
Suite A
Carlsbad, California 92008
760-918-9444
www.rinconcons ultan ts.com
June 18, 2023
Project No: 22-13460
Stacey Love
U.S. Fish and Wildlife Service, Carlsbad Office
2177 Salk Avenue #250
Carlsbad, California 92008
Via email: [email protected]
Subject: Coastal California Gnatcatcher Protocol Survey Report Woodward Specific Plan Development Project
San Marcos, San Diego County, California
Dear Ms. Love:
Rincon conducted protocol breeding season coastal California gnatcatcher ( Polioptila californica californica; CAGN) for the proposed Woodward Specific Plan Development Project (Project) to further evaluate presence/absence of the s pecies as part of the environmental review process . Rincon is submitting this letter report summarizing the results of focused surveys for the federally threatened CAGN.
Surveys were conducted by Rincon biologist Kelly Rios who currently holds an Endangered and Threatened Species Permit issued by the United States (U.S.) Fish and Wildlife Service (USFWS), Permit TE 018909 -6, under Section 10(a)(1)(A) of the Federal Endangered Species Act. The 15 -day notification letter of intent to conduct protocol breeding season surveys for CAGN was sent to the USFWS Carlsbad office on April 18, 2023.
Project Location and Environmental Setting
The 8.57 -acre project site is l ocated in the city of San Marcos and is situated 0.4 mile north of Highway 78 (Figure 1). The project site is loc ated within the U.S. Geological Survey 7.5 -minute topographic quadrangle San Marcos, California (See attached map, Figure 2). The project site is specifically located to the east of Woodward Street and north of East Mission Road (Figure 3). The project site is also located within the boundaries of the San Diego County Multiple Habitat Conservation Program (MHCP) subarea plan and is located adjacent to a 7.73 -acre open space MHCP Hardline Reserve land to the north, east, and wes t of the project site across Woodward Street (Figure 4).
The City of San Marcos implements portions of the MHCP through subarea plans, which describe specific implementing mechanisms such as the MHPA pursuant to Section 10(a) of the Federal ESA and the Natural Community Conservation Program (NCCP) plan pursuant to the California NCCP Act of 1991 and the California ESA.
Focused CAGN surveys were conducted for 16.46 acres of Diegan coastal sage scrub and disturbed Diegan coastal sage scrub habitat within the project site and surrounding 250 foot buffer, referred to as the “study area /survey area” (Figure 5). The project site occurs on a rolling hillside with slopes generally facing west and southwest.
U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
2 Figure 1 Regional Location
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U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
3 Figure 2 Project Location on USGS 7.5-minute Topographic Quadrangle
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U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
4 Figure 3 Project Site
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U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
5 Figure 4 Project Vicinity to MHCP Conservation Areas
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U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
6 Figure 5 Project Site, Project Impact Area, and Vegetation Map
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U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
7 Diegan Coastal Sage Scrub
Diegan Coastal Sage Scrub is dominated by low, soft-woody subshrubs that are most active in winter and early spring. Many taxa are facultatively drought -deciduous and typically grow in low moisture - availability sites, such as steep, xeric slopes or clay -rich soils that are slow to release stored water.
Dominant plant species in Diegan Coastal Sage Scrub usually include California sagebrush (Artemisia californica), California buckwheat (Eriogonum fasciculatum), deerweed (Acmispon glaber), chaparral mallow ( Malacothamnus fasciculatus), laurel sumac ( Malosma laurina), lemonade berry (Rhus integrifolia), and black sage (Salvia mellifera) (Oberbauer et al. 2008). Diegan Coastal Sage Scrub is considered a sensitive community by the City, falling under the Habitat Group C.
Diegan Coastal Sage Scrub is dominated by low, soft-woody subshrubs that are most active in winter and early spring. Many taxa are facultatively drought -deciduous. This community is typically on low moisture-availability sites such as steep, xeric slopes or clay-rich soils that are slow to release stored water.
This vegetation community is the most prevalent community within the study area (16.27 acres). The majority of the project site, as well as the study area to the north, supports high-quality Diegan Coastal Sage Scrub.
The shrub layer is dense and dominated by laurel sumac (Malosma laurina), California sagebrush (Artemisia californica) and lemonade berry (Rhus integrifolia), with California buckwheat (Eriogonum fasciculatum), deerweed (Acmispon glaber), white sage (Salvia apiana), black sage (S. mellifera) and coyote brush (Baccharis pilularis) (Oberbauer et al. 2008). Several non-native species including tocalote (Centaurea melitensis), mustards (brassica sp.), slender wild oat (Avena barbata) and ripgut brome (Bromus dianrus) are also common throughout this community. The northern portion of the survey area consisted of more dense shrub cover compared to the central and southern portions.
Historical disturbance within the central portion of the site identified 0.88 acre of a more Disturbed Diegan Coastal Sage Scrub community, with evidence of revegetation in the last several years.
Disturbed Diegan Coastal Sage Scrub is also prese nt within the central and southern edges of the project site and within the study area to the south.
The central and southern portion of the project site contained disturbed Diegan Coastal Sage Scrub that was revegetating in historically disturbed areas , i ncluding fuel medication breaks. Dominant shrub species include d California buckwheat, California sagebrush, black sage, coyote brush, with golden yarrow ( Eriophyllum confertiflorum ) and sparse herbaceous species, including giant woollystar ( Eriastrum dens ifolium) and small seed sandmat ( Euphorbia polycarpa ) and larges patches of open/bare ground.
Species Background
The CAGN is a non -migratory songbird found on the coastal slopes of southern California. It ranges from Ventura County south to northwest Baja California, Mexico (Atwood et al. 1999; Jones and Ramirez 1995). The CAGN belongs to the old -world warbler and gnatcatcher family, Sylviidae. It is a small blue -gray songbird which measures 4.5 inches (11 centimeters) and weighs 0.2 ounces (6 grams). It has dark blue -gray feathers on its back and grayish -white feathers on its underside. The wings have a brownish wash. Its long tail is mostly black with white outer tail feathers. The species has a thin, small bill. The males have a black cap dur ing the spring and summer which is absent during the winter. Both males and females have a white ring around their eyes. r
U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
8 The breeding season of the CAGN extends from late February through August with the peak of nesting occurring from mid -March through mid-May. The breeding territory size of the CAGN ranges from two to 22 acres ( one to nine hectares), with home ranges expanding up to 39 acres (16 hectares), during the non -breeding season (Bontrager 1991; USFWS 1993). Nest parasitism by brown-headed cowbirds (Molothrus ater) has been documented (Unitt 1984). Typically, there is a high rate of nest failure each breeding season. This is offset by rapid and persistent re -nesting efforts; a breeding pair may attempt to nest as many as ten times in a year, produci ng up to three successful broods in a season (Atwood and Bontrager 2001). There is evidence that this species is also susceptible to nest predation by various animals such as snakes, coyotes ( Canis latrans), fox, rodents, and other birds, such as California scrub-jays (Aphelocoma californica) (Atwood et al. 1999).
CAGN are strongly associated with coastal sage scrub habitats below 820 feet in coastal areas and between 820 and 1,640 feet in inland areas (Atwood and Bolsinger 1992); however, not all types of coastal sage scrub communities are used or preferred. This species is reported to be most abundant in areas dominated by California sagebrush and California buckwheat. CAGN numbers are generally low in coastal habitats dominated by black sage, white sage ( Salvia apiana), or lemonade berry; in inland areas, habitats dominated by black sage may be used more regularly (Atwood and Bontrager 2001).
Population estimates for the CAGN vary. Atwood (1992) estimated that 1,811 to 2,291 pairs of CAGN existed in 1992 t hroughout its range in southern California. In 1996, the USFWS estimated the population in San Diego County at 3,000 pairs, excluding pairs located on sites where habitat loss had already been approved (Atwood and Bontrager 2001). According to a 1999 popul ation estimate in San Diego and other southern California counties, the USFWS estimated the population in San Diego at 1,917 pairs, Orange County at 643 pairs, Los Angeles County at 144 pairs, San Bernardino County at 27 pairs, and Ventura County at 4 pairs (Atwood and Bontrager 2001).
The CAGN is federally listed as threatened and is a California Department of Fish and Wildlife (CDFW) Species of Special Concern. The USFWS listed the CAGN as threatened (USFWS 1993) pursuant to the federal Endangered Species Act of 1973 as amended on March 30, 1993. Critical habitat was designated for CAGN on October 24, 2000 (USFWS 2007).
The primary cause of this species’ decline is the cumulative loss of its coastal sage scrub vegetation community to urban and agricultural development. The USFWS has estimated that coastal sage scrub vegetation has been reduced by 70 to 90 percent of its historical extent (USFWS 1991) and little of what remains is protected in natural open space.
Survey Methodology
Focused Surveys
Notification to commence protocol surveys was provided via email correspondence to the USFWS on April 18 , 2023 . Kelly Rios, permitted Rincon biologist, conducted all CAGN surveys in accordance with the survey protocol for CAGN surveys within M HPA areas, titled Section III of the USFWS Coastal California Gnatcatcher Presence/Absence Survey Protocol , issued February 28, 1997, and revised July 28, 1997. The protocol requires that between February 15 and August 30, a minimum of six surveys shall be conducted at least one week apart to determine presence/absence of CAGN.
A total of six surveys were conducted between May 3 and June 14, 2023. The six surveys occurred between 0600 and 1200 hours each day. Suitable Diegan Coastal Sage Scrub occurs within the project site boundaries, north and east of the project site, and west of the project site across r
U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
9 Woodward Street . The study area consists of predominately Diegan Coastal Sage Scr ub and disturbed Diegan Coastal Sage Scrub . Larger, more dense shrub cover within the community dominated by laurel sumacs (Malosma laurina) and California sage brush occurs in the northern portion of the survey area. Additional open space MHCP Reserve Habitat is adjacent to the project on the north and east sides (Figure 5).
A total of approximately 16.46 (6.6 hectares) were surveyed and did not exceed the maximum of 100 acres per survey day. Surveys were not conducted during periods of excessive or abnormal heat, wind, fog, and other inclement weather. Surveys were conducted with binoculars to aid in bird detection. The biologist slowly walked the survey area, stopping at approximate 50-foot intervals and used an audio recording of coastal CAGN vocalizations after individuals had been initially located.
Recorded CAGN vocalizations were played sparingly and only if other means of detection had failed.
If a CAGN was detected before playing recorded vocalizations, the recordings were not played. If CAGN is detected in response to the tape play, use of playback was discontinued immediately. If any CAGN were observed, age, sex, breeding status, and behavioral characteristics were recorded, if possible; the protocol level surveys did not include focused nest searches.
Survey Results
Details on the date, surveyor, time, conditions, and CAGN survey results are provided in Table 1.
Table 1 Coastal California Gnatcatcher Survey Conditions and Results Date Surveyor Survey Conditions Survey Results
5/3/23 Kelly Rios 630-830 AM
Winds 1–2 mph
100% Cloud Cover
53-54°F
No CAGN observed
5/10/23 Kelly Rios 945-1145 AM
Winds 1–2 mph
100% Cloud Cover
59-62°F
No CAGN observed
5/17/23 Kelly Rios 1000AM-1200 PM
Winds 1–2 mph
95% Cloud Cover
65-68°F
No CAGN observed
5/24/23 Kelly Rios 1015AM-1200PM
Winds 1–2 mph
100% Cloud Cover
58-60°F
No CAGN observed
5/31/23 Kelly Rios 930-1130 AM
Winds 1–2 mph
100% Cloud Cover
1-2°F
No CAGN observed
6/14/23 Kelly Rios 0900-1100 AM
Winds 1–2 mph
100% Cloud Cover
64-66°F
No CAGN observed
During the 2023 protocol surveys, no observations of any CAGNs were recorded. CAGN surveys were conducted in 2018 and 2020 for the Mission 316 West Project (KMEA 2019) located just south of r
U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
10 the project site which included the Woodward Specific Plan Project 2023 survey area . CAGN observations were documented within the subject project limits. Further details regarding these observations are provided in the Conclusions section below.
Avian activity levels and diversity were generally high during the recent surveys. Common species expected to occur within coastal sage scrub and adjacent disturbed, and urban/developed habitats were observed on a regular basis. A complete list of avian species detected by sight or sound during the surveys is included in Table 2.
Table 2 Species Observed during Protocol Level Surveys
Scientific Family, Name Species
Accipitridae Hawks, Kites, & Eagles
Accipiter cooperii Cooper’s hawk
Buteo jamaicensis red-tailed hawk
Aegithalidae Bushtits
Psaltriparus minimus bushtit
Apodiformes Swifts
Aeronautes saxatalis white-throated swift
Bombycillidae Waxwings
Bombycilla cedrorum cedar waxwing
Cathartidae New World Vultures
Cathartes aura turkey vulture
Columbidae Pigeons & Doves
Zenaida macroura mourning dove
Corvidae Ravens, Crows, Jays, & Magpies
Aphelocoma californica California scrub-jay
Corvus brachyrhynchos American crow
Corvus corax common raven
Emberizidae Emberizids
Pipilo crissalis California towhee
Pipilo maculatus spotted towhee
Fringillidae Finches
Haemorhous mexicanus house finch
Spinus psaltria lesser goldfinch
Icteridae Orioles, Grackles, Cowbirds
Icterus cucullatus hooded oriole
Mimidae Mockingbirds & Thrashers
Mimus polyglottos Northern mockingbird
Toxostoma redivivum California thrasher
Timaliidae Babblers
Chamaea fasciata wrentit
Troglodytidae Wrens
Thryomanes bewickii Bewick’s wren
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U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
11 Scientific Family, Name Species
Troglodytes aedon house wren
Passerellidae Sparrows
Melospiza melodia song sparrow
Parulidae New World Warblers
Setophaga petechia yellow warbler
Picidae Woodpeckers, Wrynecks, and Sapsuckers
Colaptes auratus Northern flicker
Dryobates nuttallii Nuttall’s woodpecker
Odontophoridae New World Quail
Callipepla californica California quail
Trochilidae Hummingbirds
Calypte anna Anna’s hummingbird
Tyrannidae Tyrant Flycatchers
Empidonax difficilis Pacific-slope flycatcher
Sayornis nigricans black phoebe
Tyrannus vociferans Cassin’s kingbird
Conclusions
During the 202 3 CAGN protocol surveys, no individuals, pairs, or nests were observed within the study area or adjacent areas. CAGN had been previously identified in the Diegan Coastal Sage Scrub within the project area, including within the overall study area to the east and west , during USFWS protocol surveys that were conducted in 2018 and preconstr uction surveys conducted in 2020 for the adjacent Mission 316 development project located south of the project area (KMEA 2019). The Survey Area for the Mission 316 protocol CAGN surveys totaled 28 acres, which included a 500 -foot buffer around the 3.7-acre project to the south. These surveys recorded individuals foraging, nesting pairs, and two family groups within the proposed Woodward project area . Individuals were also recorded within sage scrub habitat and designated MHCP Hardline Reserve to the west of the project site across Woodward Street. Foraging individuals were also observed and recorded to the adjacent area east of the project site, south of Silk Mill Place Road.
Recommendations
Although no CAGN were observed, Rincon recommends conducting pre-disturbance protocol surveys and implementing additional avoidance measures in accordance with mitigation measures outlined in the Biological Resources Technical Report (Rincon, 2023) prepared for the City of San Marcos.
Certification
I certify that the information in this survey report and attached exhibits fully and accurately represents my work.
Sincerely,
Rincon Consultants, Inc.
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U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
12 Kelly Rios, TE 018909-6 Jared Reed
Permitted Biologist Project Manager/Senior Biologist
Jacob Hargis
Biologist
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U.S Fish and Wildlife Service
Coastal California Gnatcatcher 2023 Focused Survey Report Woodward Specific Plan Development Project
13 References
Atwood, J. L. 1992. A maximum estimate of the California Gnatcatcher's population size in the United States. Western Birds 23:1-9.
Atwood, J. L., C. A. Reynolds, and S. L. Grove. 1999. Distribution of California Gnatcatchers on Camp Pendleton Marine Corps Base. Prepared for U.S. Marine Corps, Oceanside, California (Contract No. M00681-97-C-0035). Unpublished technical report, February 14, Manomet Center for Conservation Sciences, MA.
Atwood, J.L. and J.S. Bolsinger. 1992. Elevational distribution of California Gnatcatchers in the United States. Journal of Field Ornithology 63: 159-168.
Atwood, J.L. and D.R. Bontrager. 2001. California Gnatcatcher (Polioptila californica). In A. Poole and F. Gill (eds.) The Birds of North America No. 574. Philadelphia, PA.
Bontrager, D. 1991. Habitat Requirements, Home Range and Breeding Biology of the California Gnatcatcher (Polioptila californica) in South Orange County. Santa Margarita Company.
United States Fish and Wildlife Service. 1991. Summary of the proposed rule to list the coastal California gnatcatcher (Polioptila califomica) as endangered in California and Baja, Mexico.
September. 114 pp.
United States Fish and Wildlife Service. 1993. Federal Register, Endangered and Threatened Wildlife and Plants; Determination of Threatened Status for the Coastal California Gnatcatcher; Final Rule. March 30.
United States Fish and Wildlife Service. 1997 Coastal California Gnatcatcher (Polioptila californica californica) Presence/Absence Survey Protocol. Available at:
https://www.fws.gov/ventura/docs/species/protocols/cagn/coastal-gnatcatcher_survey- guidelines.pdf.
United States Fish and Wildlife Service. 2007. Federal Register, Endangered and Threatened Wildlife and Plants; Revised Designation of Critical Habitat for the Coastal California Gnatcatcher (Polioptila californica californica); Final Rule. December 19.
Unitt, P. A. 2004. San Diego County Bird Atlas . Proceedings of the San Diego Society of Natural History, No. 39. San Diego Natural History Museum
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Attachment 1
15-Day Notification of Intent Letter
Rincon Consultants, Inc.
2 2 1 5 F a r a d a y A v e n u e , S u i t e A
Carls ba d, Ca lif or ni a 9 20 08
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E n v i r o n m e n t a l S c i e n t i s t s P l a n n e r s E n g i n e e r s April 18, 2023
Ms. Stacey Love
United States Fish and Wildlife Service
Carlsbad Fish and Wildlife Office
2177 Salk Avenue, Suite 250
Carlsbad, California 92008
Via email: [email protected]
Subject: Notification of Intent to Conduct Protocol Breeding Season Surveys for Coastal California Gnatcatcher for the Woodward Specific Plan Development Project in San Marcos, San Diego County, California.
Dear Ms. Love:
In accordance with the current United States (U.S.) Fish and Wildlife Service (USFWS) survey protocol for coastal California gnatcatcher (Polioptila californica californica; CAGN) (dated February 28, 1997), please consider this letter as notification of the intent to commence protocol breeding season surveys for the Woodward Specific Plan Development Project (project site). The 8.57-acre project site is located to the east of Woodward Street and north of East Mission Road and is situated 0.4 mile north of Highway 78.
The project site is located within the U.S. Geological Survey 7.5-minute topographic quadrangle San Marcos, California (See attached map, Figure 1).
The project is located within the boundaries of the San Diego County Multiple Habitat Conservation Program (MHCP) subarea plan and is located adjacent to a 7.73-acre open space MHCP Hardline Reserve land to the north, east, and west of the project site across Woodward Street. The surveys would be conducted for 15.48 acres of Diegan coastal sage scrub and disturbed Diegan coastal sage scrub habitat within the project site and adjacent to the north, east south and west.
The survey area is outside of the County of San Diego’s Natural Community Conservation Plan, therefore a minimum of six (6) surveys will be conducted at least one (1) week apart from May 3 through June 30 following the 15-day notification period. A final report will be submitted to the USFWS within 45 days following the field surveys adhering to the report guidelines outlined in the USFWS Coastal California Gnatcatcher Presence/Absence Survey Protocol.
All CAGN surveys will be conducted by Kelly Rios, 10(a)(1)(A) permit no. TE 018909-5 with Rincon Consultants, Inc. (Rincon) within the 15.48-acre survey area.
Please let us know if you have any questions or concerns.
Sincerely,
Rincon Consultants, Inc.
Jared Reed, Senior Biologist/Project Manager
Attachments
Figure 1 USGS Topographic Map
Figure 2 Project Location
Figure 1 Project Site
0 1,000
Feet
Basemap provided by National Geographic Society, Esri, and their /icensors © 2023. San Marcos Quadrangle . T125 R03W 511.
The topographic representation depicted in this map may not portray all of the features currently found in the vicinity today and/or features depicted in this map may have changed since the original topographic map was assembled.
Figure 2 Project Location
,. - I Study Area
0 125 250
Feet