Furthermore, as road width, traffic volume, and speeds increase, the potential for direct impacts, such as vehicle strike will increase. Roads throughout the range of the San 1 Urban Roads and the Endangered San Joaquin Kit Fox
Joaquin kit fox are increasing in traffic volume. Therefore, lack of direct impact on San Joaquin kit fox as reported above is not necessarily indicative of future relationships between the kit fox and human transportation networks. For a synthesis of the literature on road impacts on San Joaquin kit fox refer to Cypher (2000) and Bjurlin and Cypher (2003).
The highest density of roads, peak traffic volume, and greatest potential for impact to foxes occurs in urban areas. Urban kit fox populations in California minimally occur in Bakersfield, Taft, Santa Nella, and Coalinga. Reports from the public and carcasses collected opportunistically indicate that kit foxes are dying by vehicle strike in the human developments of the Southern San Joaquin Valley. Urbanized foxes may encounter roads while foraging, looking for mates, defending territories, and dispersing. Little is known, however, about the factors that influence where, when, and how vehicle strikes occur.
Furthermore, it is unknown whether there are changes to kit fox use or placement of dens, patterns of movement, susceptibility to predation, prey selection, or other elements of fox ecology as a consequence of proximity to roads in urban areas.
Why is the impact of urban roads on kit fox populations important? First, urban areas have rapidly grown throughout the range of the kit fox. In some cases, development has occurred in agricultural lands that long have been devoid of kit foxes. But in many other cases, urbanization has displaced or altered fox populations occurring in natural lands.
Conversion of natural lands permanently decreases availability of habitat, which is a major obstacle to species recovery. Second, the network of three core- and several satellite-populations identified in the recovery plan for this species is vulnerable to fragmentation associated with transportation networks. For this metapopulation to remain functional, individuals must be able to move between sub-populations. The potential for negative impact of roads on the ability of foxes to utilize corridors may be proportional to road width, traffic volume, and speed limit. Projections for the San Joaquin Valley indicate that the human population and associated urbanization and transportation networks will increase for the foreseeable future. The highest potential for fragmentation will occur in urbanized areas where roads are most prevalent. Third, as urban lands spread and natural lands diminish, urbanized fox populations may become more valuable to species recovery. Urban fox populations are relatively less susceptible to meteorological stochasticity, and may prove useful as a repository for genetic diversity and/or individuals for reintroduction efforts. Consequently, the influence of transportation networks on San Joaquin kit fox recovery is likely to grow simultaneously to the importance of urbanized fox populations where transportation networks are most prevalent. Identifying ways to reduce the impact of urban roads on the kit fox is therefore a conservation priority.
A less tangible, but still important, reason to reduce the impact of roads on urban fox populations is the interaction between urbanized kit foxes and the public. Standardized surveying shows that the citizens of Bakersfield (where the largest population of urbanized foxes occurs) generally have seen a kit fox on one or more occasions and support protection of the urban population (Bjurlin and Cypher, in press). Furthermore, respondents expressed widespread appreciation of urbanized foxes (in some cases becoming strongly protective). The greatest concern identified by respondents was that kit foxes would be killed by vehicle strike. Furthermore, fox-vehicle collision, or the 2 Urban Roads and the Endangered San Joaquin Kit Fox
attempt to avoid it, may in some cases contribute to traffic accidents (unconfirmed citizen report) or unsafe road conditions. Measures designed to minimize kit fox crossing of busy roads at grade are likely to receive strong public support. To the extent that pedestrian and fox crossing structures can be combined for multiple use, the perceived benefits of this investment in infrastructure are likely to increase.
GOAL
Our goal was to determine whether roads affect the ecology of the urbanized San Joaquin kit fox. From 1997-2004, we outfitted kit foxes with radio transmitters and monitored survival, den use patterns, and movements. We examined these data for statistical and spatial associations to urban road networks. Based upon these results we provide detailed recommendations for the protection of San Joaquin kit foxes in urban environments during and after road projects. If implemented, these recommendations are likely to contribute to the long-term viability of urban fox populations and species recovery, receive strong public support, and may even increase public safety.
STUDY AREA
The study site is located in the southwestern quarter of the Bakersfield metropolitan area (Figure 1). Bakersfield lies at the southern end of the San Joaquin Valley in central California and is the Kern County seat of government. The metropolitan area as of January 2003 was approximately 580 km2
(224 mi
2 ) with 394,234 residents
(http://www.bakersfieldchamber.org/pdf/community-profile.pdf). The urbanized area of Bakersfield grew by 23.6% from 1990-2000 and continued growth is expected (http://factfinder.census.gov/home/saff).
Hot, dry summers, and cool, wet winters characterize the climate of the southern San Joaquin Valley. Average daily maximum temperatures range from 14°C in December to 37°C in July and average daily minimum temperatures range from 4°C in December to 21°C in July (Meadows Field Airport weather station). Annual precipitation averages
14.3 cm, but varies greatly between years.
3 Urban Roads and the Endangered San Joaquin Kit Fox
METHODS
KIT FOX CAPTURE AND MONITORING
From May 1997 to July 2004 we captured kit foxes in live traps, outfitted them with radio transmitters, and monitored them for sources of mortality, nightly movements, daily resting places, and reproductive output. We captured foxes with wire-mesh box traps (38 x 38 x 107 cm) baited with assorted meats. Traps were covered with cloth tarps to protect animals from inclement weather and direct sun. Captured foxes were examined for injury and parasites, ear-tagged, sexed, aged, and fitted with a radio collar (40g, Advanced Telemetry Systems, Isanti, Minnesota) containing a mortality sensor that altered signal pulse rate if the animal was motionless for four hours. We released foxes at site of capture after 0.5-1 hour of handling. Capture and handling protocols were in accordance with permits TE023496-1 and TE825573-2 from the U.S. Fish and Wildlife Service and a Memorandum of Understanding from the California Department of Fish and Game.
Figure 1. Urbanized San Joaquin kit fox study area, Bakersfield, CA. 4 Urban Roads and the Endangered San Joaquin Kit Fox
At a minimum, we attempted to record one day-resting location and two night-activity locations for each animal with a functioning radio collar during each week. In some cases fewer locations were recorded because of collar failure, fox dispersal from typical home ranges, use of resting sites that attenuated radio signal, or other factors. Radio collar transition to mortality signal allowed us to promptly retrieve deceased foxes and increased the likelihood of confirming cause of mortality. Fox carcasses also were collected opportunistically during the study when spotted on roads, reported by citizenry, or collected by other organizations. Each spring, we conducted natal den observations to estimate litter size for all radio-tagged females. Finally, we collected kit fox feces for dietary analysis throughout the study duration. Locations of activity, mortality, resting, and pup whelping and rearing were recorded with GPS and entered in a GIS for spatial analysis.
MORTALITY
We conducted necropsy for all recovered fox carcasses. We limited our analysis of cause of death to animals that were actively being monitored with radio telemetry in order to decrease bias caused by differences in visibility of carcasses. We also report, however, on all carcasses retrieved during the study. Cause of death was determined using the pattern of injury, including external abrasion, broken bones, internal hemorrhaging, and bite wounds. The location that the carcass was retrieved from also was used in determining cause of death (e.g., within road right-of-way, buried at construction site, in carnivore scrape, etc.).
For all animals (transmitting or not) that died by vehicle strike, we assigned road type (local, collector, arterial, highway), traffic volume, and posted speed limit. Local roads had the primary purpose of providing access to abutting residential property, did not exceed 12.2m (40ft) in width, had no more than one traffic lane in each direction, and were not longer than 0.8km (0.5mile) without interruption. Speed limit was 25mph on all local roads, but was not always posted. Collector roads generally conducted local road traffic to the arterial road network, but sometimes were residential in nature. Speed limits (generally 30-45 mph) for collector roads were based upon speed surveys and were posted. Arterial roads had 1-3 lanes of traffic in each direction (typically more than one), carried the majority of city traffic, and connected the local and collector road networks to the State highway system. Arterial road speed limits (35-55mph) were always based on speed surveys and posted. Lastly, highways were State numbered roads with the primary purpose of conducting traffic into and away from the urban area. They included highways 58, 99, 178, and 119 and in some cases passed through residential, commercial, and industrial areas. Vehicle access to highway 99 and portions of 178 was by ramp only.
We compared road type where foxes died to an expected distribution based on road availability using contingency table analysis. Road availability was calculated by summing the length of three road types (local, collector, arterial) within the minimum convex polygon of the locations of vehicle strike (Figure 2). Vehicle strikes also were examined for temporal patterns. For this analysis we limited the time period to 6 complete years, 07/01/1998-06/30/2004 so that months wouldn’t be disproportionately represented. Strikes were separated by fox age (adult, juvenile) and gender (male, 5 Urban Roads and the Endangered San Joaquin Kit Fox
female) and compared with other sources of morality by month. Temporal distribution in strikes was compared with frequency of fox scent marking, interaction with foxes outside of social group (Murdoch 2004), and traffic volume by month.
Finally, we examined spatial patterns of kit fox vehicle strikes that occurred on arterial or collector roads. We had insufficient sample size to conduct similar analyses for local and highway strikes. We limited the extent of this analysis to southwest Bakersfield where we had the greatest knowledge of roads and fox habits. Strikes were examined for association with intersections of the road where the mortality occurred and other linear rights-of-way. Linear rights-of-way for this analysis were defined as other roads (local, collector, arterial, highway), canals, railroads, rivers, or golf course crossings.
Figure 2. Minimum convex polygon of fox-vehicle collisions for individuals that had transmitting radio collars, Bakersfield, CA, 1998-2004. 6 Urban Roads and the Endangered San Joaquin Kit Fox
In order to conduct this spatial analysis, we defined vehicle strike road segments. These segments were the shortest sections of road that were bounded by intersection with other arterial or collector roads and contained the vehicle strike location. This rule was modified when the mortality occurred at an intersection with arterial or collector road. In these cases, the segment was extended in both directions to the next, nearest intersection with a major road. We then assigned 100 randomly distributed points to the road segment for each vehicle strike. For example, if three strikes occurred on the segment, 300 randomly distributed points were assigned. We calculated the distance to nearest intersection with linear right-of-way for all points (confirmed strike and random).
Distance was coded into three categories, near (x <= 26m), intermediate (26m < x <= 52m), and far (52m < x) based on a mean road width of 26m. Therefore, strikes assigned as “near” occurred within one road width of the intersection, as “intermediate” within two road widths, and as “far” greater than two road widths.
Observed strikes versus random locations were examined with this coding scheme in a contingency table analysis for a departure from what would be expected by chance.
Lastly, we evaluated the type of intersections where vehicle strikes occurred for strikes coded as “near”. We then compared the frequency of observed mortalities and random points among intersection types.
DENS
Association between confirmed kit fox dens and major roads (highway, highway ramp, arterial, and collector) was examined for dens used by radio-collared foxes from 1 July 2001 to 30 June 2004. Distance to nearest road centerline was calculated for each known den and compared across distance categories (34.5m, 69m, etc.). Distance categories corresponded with Fish and Wildlife exclusion zone distances for known kit fox dens (34.5m = 100ft).
MOVEMENTS
Kit fox space use was studied using vehicle-based monitoring of focal animals during 2003. Focal sessions typically began 1 or more hours after nightfall (full dark) and lasted for approximately four hours. Every 15 minutes we attempted to collect a new location for the focal animal. We described fox locations as accurately as possible using a combination of triangulation and spotlighting. With these data we calculated minimum straight-line distance (MSLD) between consecutive locations. We also calculated rate of travel (MSLD km/hour). Finally, we estimated number of road crossings (arterial, collector, local) using MSLD and visual sightings. We then adjusted these data for crossing rate per hour of observation and MSLD of movement. We used shapefile coverages of city roads and geo-referenced aerial photography to assign road crossings for this analysis.
7 Urban Roads and the Endangered San Joaquin Kit Fox
SPATIAL AND STATISTICAL ANALYSIS
Spatial analysis was conducted using ArcView version 3.2 (ESRI 1996). Data for roads and traffic volumes were generated with shapefile coverages from City of Bakersfield GIS and Traffic Engineering Departments, respectively (City of Bakersfield 2000-2004).
All spatial data were projected in Lambert Conformal Conic, California State Plane, NAD27. In some cases data on road location, size, or posted speed limit was unavailable for the year in which the kit fox feature was described (i.e., vehicle strike, den, movements). In these instances data from the closest available time period were used (usually less than one year distant). Geo-referenced aerial photography (AirPhoto USA) was used to assign the location of road intersections with other linear rights-of-way. All statistical analyses were performed using SPSS version 11.5 (SPSS Inc. 2002) and results were considered significant at P <= 0.05.
San Joaquin Kit Fox
8 Urban Roads and the Endangered San Joaquin Kit Fox
RESULTS
URBAN KIT FOX ECOLOGY
From May 1997 to July 2004 we captured a total of 358 individual foxes (109 adults, 206 juveniles, and 43 juveniles that were captured again as adults). Of these, we outfitted 229 individuals with radio collars (84 adults, 79 juveniles, and 66 juveniles that continued to be monitored as adults). We monitored radio-tagged animals until they died, transmitters failed, or they were lost. We collected 8,115 night activity locations and 6,647 daytime resting locations during the study (Figure 3a-b). Kit foxes primarily rested diurnally within dens, of which we described 471 over the study period. We located kit fox litters on 54 separate occasions. With these data we will conduct additional analyses on survival rates, reproductive rates, den site selection, space requirements, preferred habitats, and foraging patterns. We will present these data in a comprehensive monograph of kit fox demographics and ecology in urban environments. California Department of Transportation (Caltrans) will be supplied with a copy of the monograph and associated recommendations for the conservation of urban fox populations.
MORTALITY
We collected 156 kit fox carcasses from September 1985 to August 2004. Carcasses collected prior to 1997 were stored by California State University, Bakersfield. A near majority of mortalities were attributed to vehicle strike (48.1%, Table 1). These data, however, include animals that were received from a variety of opportunistic sources. By limiting analysis to animals that were actively being monitored with radio telemetry at time of death (N = 78) we reduce bias (e.g., differential reporting and accessibility to carcasses). Of this subset, confirmed vehicle strike accounted for 26.9% of mortality.
An additional 7.7% of foxes may have died from vehicle strike, but evidence, while suggestive, was not conclusive. Predation (16.7%) was the second most common cause of death for transmitting animals. Other sources of mortality included entombment, poison, drowning, gunshot, complications during parturition, and entanglement.
Due to advanced state of decay or lack of gross injury, we were unable to determine cause of death for 28.2% of carcasses. However, 73% of the 22 individuals with unknown cause of death were retrieved from fox dens. Pertinent to this report, animals retrieved from dens were unlikely to have died of vehicle strike (they lacked broken bones or contusions), and therefore the percentages calculated for vehicle strike are considered accurate when unknown cause of death is included. Overall, 30.8% of the 78 mortalities of foxes with operational radio collars were retrieved from dens. In natural lands where most research has been conducted and mortality generally is attributed to predation, carcasses are rarely retrieved from dens. There may be sources of mortality in urban environments (e.g., disease or poisoning) that have yet to be identified, but that do not leave clearly diagnostic evidence with our necropsy techniques. 9 Urban Roads and the Endangered San Joaquin Kit Fox
Figure 3. Nocturnal (a) and Diurnal (b) locations of San Joaquin kit fox in Bakersfield, CA, 1998-2004.
10 Urban Roads and the Endangered San Joaquin Kit Fox
Table 1. Cause of death for all foxes (1985-2004) and foxes with transmitting radio signals at time of death (1997-2004), Bakersfield, CA.
Cause of Death All Foxes Transmitting Foxes
N % N %
Entombed - construction 5 3.2 3 3.8
Entombed - natural 1 0.6 1 1.3
Poison 3 1.9 0 0.0
Possible poison 5 3.2 4 5.1
Predation 16 10.3 13 16.7
Possible predation 5 3.2 4 5.1
Vehicle 75 48.1 21 26.9
Possible vehicle 8 5.1 6 7.7
Other 6 3.8 4 5.1
Unknown 32 20.5 22 28.2
Total 156 100.0 78 100.0
Table 2. Frequency of fox-vehicle collisions by road type for all foxes and those with transmitting radio signals at time of death, Bakersfield, CA, 1998-2004.
Road Type All Strikes Transmitting Strikes
N % N %
2-lane local 2 4.2 1 5.6
2-lane collector 8 16.7 1 5.6
2-lane arterial 2 4.2 1 5.6
4-lane arterial 17 35.4 7 38.9
6-lane arterial 16 33.3 7 38.9
6-lane highway 1 2.1 0 0.0
Not on road 2 4.2 1 5.6
Total 48 100.0 18 100.0
From January 1998 to August 2004, we had the necessary information on road status to describe association between road types and vehicle strikes. We retrieved 48 vehicle strike kit foxes in Bakersfield during this period. Of these, 18 were actively being monitored with radio telemetry at the time of death. Arterial roads accounted for 72.9% and 83.3% of strikes for all animals and actively monitored animals, respectively (Table 2). Collector roads, local roads, and highways were less significant sources of mortality. Within the 100% MCP of actively monitored animals (Figure 2), we identified 327.4 km of local roads, 49.9 km of collector roads, and 50.9 km of arterial roads. There was a significant difference between the observed frequency of roadkill by road type, and that which would be expected based on availability (χ
2 2 = 82.127, P < 0.001). Arterial
roads were far more often a source of vehicle strike than can be explained by chance occurrence.
11 Urban Roads and the Endangered San Joaquin Kit Fox
Roads with four or more lanes accounted for 70.8% and 77.8% of roadkill for all animals and actively monitored animals, respectively (Table 2). Approximately 90% of roadkill were retrieved from roads with posted speed limits of greater than 45 mph, irrespective of whether the animal was transmitting at time or death or was collected opportunistically (Table 3). Roads with a 55 mph posted speed limit accounted for over half of all vehicle strikes. Mean traffic volume at vehicle strike was 21,861 and 23,426 vehicles per day for all strikes and actively monitored strikes, respectively (Figure 4).
Table 3. Fox-vehicle collisions by posted speed limit, Bakersfield, CA, 1998-2004.
Speed Limit All Strikes Transmitting Strikes
N % N %
25 mph 1 2.1 0 0
35 mph 1 2.1 0 0
40 mph 1 2.1 1 5.6
45 mph 9 18.8 2 11.1
50 mph 6 12.5 5 27.8
55 mph 27 56.3 9 50.0
65 mph 1 2.1 0 0.0
Not on road 2 4.2 1 5.6
Total 48 100.0 18 100.0
Figure 4. Fox-vehicle collisions by traffic volume for all mortalities and mortalities of individuals with transmitting radio collars at time of death, Bakersfield, CA, 1998-2004. 12 Urban Roads and the Endangered San Joaquin Kit Fox
There was no overall interaction between vehicle strike as cause of death (Coded Yes/No) and gender (χ
2 1 = 0.057, P = 0.812) or age (χ
2 1 = 0.709, P = 0.400) for 78 foxes
that were actively being monitored at time of death. Of 47 adult mortalities, 38.3% were either confirmed or possible vehicle strikes. Confirmed or possible vehicle strike accounted for 29.0% of 31 juvenile mortalities. Mortalities were evenly distributed between the genders (male = 39, female = 39), and approximately one third of each sex died of confirmed or possible vehicle collision. While all mortalities were distributed throughout the year, vehicle strikes showed a distinct peak in December during the sixyear period beginning 1 July 1998 (Figure 5). Further examination showed an association between gender, age, and vehicle strikes when the data were examined temporally. Of nine foxes that died of vehicle collision in December, seven were adult males. The winter (December/January) spike in male fox-vehicle collision corresponded with male rate of scent marking (Figure 6) and overall rate of interaction between focal foxes and conspecifics that were not within the social group (Figure 7). Both scent marking and interaction frequency may be indicators of reproductive behavior and territoriality (Murdoch 2004). There also appeared to be a smaller increase in vehicle strike from May to September. Many of these animals were pups that were at the age typical of increasing independence from the natal group, solitary foraging, and dispersal.
Vehicle traffic volume did not differ by month at six control stations spread across the urban area (Figure 8).
Figure 5. Fox-vehicle collisions by gender and month, Bakersfield, CA, 1998-2004. 13 Urban Roads and the Endangered San Joaquin Kit Fox
Figure 6. Fox-vehicle collisions (1998-2004) versus scent marking rates (Murdoch 2004) for male foxes, Bakersfield, CA.
Figure 7. Fox-vehicle collisions (1998-2004) versus interactions with foxes that were not within the immediate social group (Murdoch), Bakersfield, CA. 14 Urban Roads and the Endangered San Joaquin Kit Fox
We identified 23 segments of arterial or collector roads where strikes occurred. Number of strikes per segment ranged from 1 to 5 and accounted for 38 strikes in all (Figure 9).
Along these segments we identified 136 intersections. Kit foxes died more often than expected by chance at intersections with a linear right-of-way (χ 2 2 = 15.75, P < 0.001).
Strikes within one road width (<=26m) of an intersection accounted for 47.3% of all roadkill. In contrast, only 22.5% of random points occurred within one road width of an intersection. Following a similar, but weaker, trend 21.1% of observed roadkill were between one and two road widths (26 < x <= 52m) of an intersection, versus 17.8% of random locations in the category. There did not appear to be a higher risk of strike at any one type of intersection. Across intersection types, frequency of vehicle strikes that occurred in the category nearest to intersections mirrored the frequency of random points (Table 4). For example, 38.9% of all strikes within one road width occurred at intersection with local roads, while 37.1% of corresponding random points occurred at local road intersections.
Figure 8. Mean (Std. Dev.) traffic volume by month at six control stations, Bakersfield, CA, 2003.
15 Urban Roads and the Endangered San Joaquin Kit Fox
Table 4. Observed versus random generated fox-vehicle collisions on arterial and collector roads that were within one road width (26m) of an intersection with a linear rightof-way, Bakersfield, CA, 1998-2004.
Intersecting Linear Feature Observed Strikes Random Points N % N %
Arterial road 1 5.6 99 11.6
Canal 4 22.2 191 22.4
Collector road 3 16.7 69 8.1
Golf course 1 5.6 59 6.9
Highway 1 5.6 58 6.8
Local road 7 38.9 317 37.1
Railroad 0 0.0 17 2.0
River 1 5.6 44 5.2
Total 18 100 854 100.0
Figure 9. Fox-vehicle collisions and road segments where mortality occurred, Bakersfield, CA, 1998-2004.
16 Urban Roads and the Endangered San Joaquin Kit Fox
DENS
Kit foxes did not appear to avoid using dens or building dens at sites that were adjacent to major roads. We calculated nearest major road (arterial, collector, highway, or highway ramp) to each of 327 fox dens used from 1 July 2001 to 30 June 2004. Of these, 9.5% occurred within 30.4m (100ft) of the nearest road centerline. A similar trend occurred for each subsequent 30.4m distance from road (Figure 10). Some foxes utilized features of a major road for den construction. One individual was known to den within a culvert beneath highway 99 (Figure 11). Other dens occurred in the embankments or underpasses of a raised portion of highway 99 (Figure 20b, Appendix), and at drainage basins (e.g., Figure 14c, Appendix) or canals directly adjacent to roads.
In some cases dens were directly adjacent to the roadway (Figure 12), but in other cases roadside dens were behind by a cement block wall or other barrier that increased isolation, decreased noise pollution, and may have made the site less likely to be impacted by human activity (Figure 13). Dens directly adjacent to roads are at risk of disturbance during road maintenance or construction. Four dens within a drainage basin at the intersection of two arterial roads (Figure 14c) were destroyed during earth moving associated with road widening and improvement. In fact, the entire drainage basin was removed in this instance. Four frequently occupied fox dens were destroyed when a local road, Kroll Way, was extended through a previously un-roaded area.
Figure 10. Number of known dens by distance to nearest centerline of major road, Bakersfield, CA, 2001-2004.
17 Urban Roads and the Endangered San Joaquin Kit Fox
Figure 11. Drainage culvert under Highway 99 in Bakersfield, CA that was used as a den by San Joaquin kit fox.
Figure 12. Kit fox dens at varying distances from collector and arterial roads in Bakersfield, CA, 2001-2004.
18 Urban Roads and the Endangered San Joaquin Kit Fox
Figure 13. Kit fox dens at varying distances from collector and arterial roads, Bakersfield, CA, 2001-2004. A barrier wall, indicated with dashed line, isolated dens from one roadway with relatively high traffic volume.
MOVEMENTS
We conducted 21 sessions of vehicle-based intensive monitoring on 15 different focal kit foxes, for a total of 4,633 minutes of observation. We collected an average of 16.2 unique locations per session. Mean interval between locations was 15.14 minutes. By connecting these locations sequentially, we were able to calculate minimum straight-line distance (MSLD) moved and minimum rate of travel. We recorded a total of 44,121m of MSLD, for an average of 2,101m per monitoring session. Using MSLD and observation time, we calculated that foxes traveled at an average rate of 0.5958 km/hr during monitoring. Of course, focal foxes were inactive during much of the focal period and minimum distances between points do not account for the more complex travel patterns that were likely to exist. Therefore, foxes traveled a greater distance in shorter time and actual rate of travel likely was considerably higher.
MSLD movements also allowed us to estimate number of road crossings during focal sessions. We directly observed foxes crossing local roads on 10 occasions and arterial and collector roads on one occasion, each. MSLD predicted that foxes made 108 road crossings during focal monitoring. The majority (79 crossings) occurred on local roads, while 12 and 17 crossings occurred on arterial and collector roads, respectively. On average, foxes made 2.43 road crossings per km MSLD and 1.46 crossings per hour during intensive monitoring. Crossing rate for arterial roads (the primary location of roadkill) dropped to just 0.32 and 0.16 crossings per km MSLD and hour, respectively.
Intersection of arterial roads with MSLD occurred in only six monitoring sessions (five individual foxes).
19 Urban Roads and the Endangered San Joaquin Kit Fox
DISCUSSION
MORTALITY
As the single largest source of mortality for the Bakersfield fox population, vehicle strike clearly is an important factor for urbanized foxes. These data are in marked contrast with all other studies on kit fox in which vehicle strike rarely exceeded 10% of mortalities and was not considered a significant influence on fox demographics or population ecology (Bjurlin and Cypher 2003). In the largest study to date on the San Joaquin kit fox in natural habitats, Cypher et al. (2000) found that predation accounted for 57.2% of 222 fox deaths while vehicle strike was identified as cause of death in only 9% of occurrences. In contrast, predation during this urban study accounted for 16.7% of mortality, while vehicle strike, at 26.9%, was a more important cause of death. The coyote is the primary predator and competitor of the San Joaquin kit fox (Ralls and White 1995, Cypher and Spencer 1998) and is not abundant in Bakersfield (Cypher unpubl. data). Coyote distribution appeared limited to the Kern River corridor in the urban area included in this study. Therefore, it is possible that vehicle strike simply replaces mortality that would otherwise have been caused by depredation, had predators been more abundant. Indeed, some urban fox populations have persisted for decades and appear relatively stable given the dynamic alteration of urban environments that occurs during development and land conversion. Analyses of urban fox population viability and the impact of vehicle strike on viability are pending.
Arterial roads accounted for most strikes, a relationship that was significantly different from expected based on availability of this road type in the urban environment. Arterial roads typically have multiple lanes, relatively higher traffic volumes, and relatively higher posted speed limits. The San Joaquin kit fox is capable of rapid travel over short distances. The swiftness of this species may enable it to safely navigate two-lane roads where vehicle speeds and traffic volumes are lower. Indeed, only 10% of strikes occurred on roads that had posted speed limits that were lower than 45 mph. Low volume and speeds on local roads make it less likely that a fox crossing the road will need to avoid more than one vehicle. In contrast, a fox crossing four- or six-lane roads may have to evade multiple vehicles, which may travel in different directions and at different rates. Average traffic volume for urban roads with fox-vehicle collisions was nearly three times the volume of two-lane highways that transverse the LoKern Natural Area, one of three core areas for the San Joaquin kit fox (Cypher et al. in prep).
The incidence of vehicle strike was not evenly distributed. Foxes died more frequently within one road width of intersections between major roads and other linear rights-of-way then expected by chance. In fact, 68.4% of strikes on major roads occurred within two road widths of an intersection. The association between intersections and vehicle strike likely was the result of kit fox movement patterns. Species of the family Canidae (dogs, wolves, coyotes, foxes) utilize linear features for travel (Trewhella and Harris 1990), and we observed urban kit foxes on linear corridors between habitat patches (C. Bjurlin, pers. obs.). Additionally, increased traffic at intersections and regular changes in vehicle speed or direction (particularly where two roads come together) could make navigating intersections confusing for foxes. Finally, roadways typically are wider at road/road 20 Urban Roads and the Endangered San Joaquin Kit Fox
intersections to accommodate turning lanes. Greater distance to traverse equals greater time on the road and greater exposure to fox-vehicle collision. The lack of association of fox-vehicle collision with a specific type of intersection suggests that this relationship is broadly applicable.
Fox gender also was linked with vehicle strike when time of year was added as a variable. Males appeared particularly vulnerable during the breeding season (Dec-Jan).
Increases in male strikes closely mirrored rate of scent marking and interaction with animals outside of the social group (Murdoch 2004). During the reproductive season, male foxes are more active, travel greater distances, are more aggressive, and spend more time chasing females in courtship and males in territory defense (C.Bjurlin, pers. obs).
Furthermore, male foxes travel outside of the home territory in search of mating opportunities during December and January (Cypher et al., unpubl. data). One male in particular made these movements nightly for a period of a week and was observed successfully mating with a female in these new territories. While this example stands out in its detail, many males were observed in extra-pair copulation and outside of the typical home range during this study. On one occasion we witnessed four foxes in rapid and aggressive chase make their way through traffic on a collector road where several mortalities were known to have occurred. As interloper, transient foxes have to contend with similar agonistic interactions with resident males. It is likely that animals occupied with mating, aggressive interactions, or in unfamiliar territory are less aware of roads and traffic.
Vehicle strike during winter months also may be affected by shorter days and daylight savings time. Peak traffic volume occurs during morning and evening commutes. In the winter, the evening commute occurs up to two hours after sunset when male foxes are likely active and seeking mates. Fox activity and peak traffic volume have the greatest likelihood of overlap on the winter solstice (the shortest day of the year). Male vehicle strikes also appeared to be centered on the solstice. In contrast, traffic volume was constant throughout the year, so it is unlikely that monthly changes in traffic (e.g., holiday travel) contributed to patterns of fox mortality.
DENS
Kit foxes did not appear to prefer or avoid dens with respect to roads in urban environments. Urban land use is non-random and areas of similar zoning often are clumped. Kit foxes have shown preference for den sites with respect to some land uses.
Of the 471 dens described from 1997-2004, 36.3% were located along the banks of canals or water detention basins. These areas, however, accounted for only a small percentage of available land area in Bakersfield. It appears that open spaces, or lightly and infrequently disturbed areas (such as canals and basins) are more influential on kit fox den site selection than the proximity or size of adjacent roadways. It is possible that a positive or negative association with roads may occur as a result of a relationship between roads and other, desirable den sites. For example, many of the water transport canals in Bakersfield are adjacent to major roadways. This pattern may reflect a planned strategy, simple convenience, or historical artifact of past development. There is no current strategy for land planning in urban areas with regards to the San Joaquin kit fox. 21 Urban Roads and the Endangered San Joaquin Kit Fox
Therefore, future development practices may increase or decrease the likelihood that foxes will select den sites near roadways.
Den proximity to major roads may elevate the risk of mortality in some cases. One family group along a collector road in Bakersfield lost two of nine juveniles to vehicle strike in 2004. The natal dens in this instance were less than 20m from the road. Kit fox pups are active and relatively naïve to external dangers, particularly in the first six months of life. Urban foxes also quickly habituate to human and vehicle presence.
While the process by which juvenile foxes learn how to successfully cross roads is unknown, there likely is a period of learning and perhaps elevated risk during youth, particularly when juveniles increase in independence and begin to venture farther from the natal site in search of prey and territory.
Fox dens are destroyed during road construction or modification. Because dens are an essential resource for the kit fox (see Appendix), development projects should avoid dens whenever possible, compensate for den destruction, and secure the necessary permissions from State and Federal authorities when altering lands upon which kit fox exist. In particular, kit foxes can be entombed within dens during earth moving. Road construction projects in Bakersfield have the potential to affect 9.5% or more of dens that occur within 100 ft of major road centerlines. The percentage of affected dens would have been far greater had local roads been included in this analysis. The Fish and Wildlife Service requires that an exclusion zone be created around these dens unless permission is given for den disturbance or destruction. The loss of den sites also decreases the general suitability of habitat, both for resident and for transient animals.
Whenever dens are potentially affected by transportation projects, we strongly encourage the supplemental protection and compensation strategies that are described in the appendix to this document.
MOVEMENTS
Our data on the movements of radio-collared animals show that kit foxes frequently cross roads. The majority of crossings occurred on local roads, mirroring their relative abundance in urban areas, but the majority of mortalities occured on arterial and collector roads. Clearly, the low traffic volumes and speeds associated with local roads decreases the danger to kit fox. While these road types, cover extensive area with the range of the fox (thereby decreasing habitat availability), loss of habitat in urban areas may be unavoidable. We do not proposal specific conservation measures for local road construction to decrease fragmentation of urban landscapes.
Arterial and collector roads offer a greater challenge. These roads accommodate an everincreasing volume of traffic in Bakersfield and other southern San Joaquin Valley human population centers. Kit foxes have shown that they can successfully cross major roads, but many animals maintained territories that did not bring them into frequent contact. It is unclear how increases in traffic volume affect the ability of animals to disperse in urban environments, which is a critical function for healthy kit fox populations.
Crossings appear to be habitual in some cases – with individual foxes repeatedly using a few locations to navigate the roadway. That and the association between fox crossings, fox-vehicle collisions, and linear rights-of-way suggest that these intersections would be 22 Urban Roads and the Endangered San Joaquin Kit Fox
likely candidates for conservation measures. While reducing speed limits and road sizes would not be practical, it may be possible to reduce the likelihood of vehicle strike on arterial and collector roads by providing safe passage for foxes. Specifically, we propose that road modification projects include wildlife crossing structures where appropriate.
Criteria for selecting locations for crossing structures and instructions for building structures and associated infrastructure are provided in the appendix to this document.
CONCLUSIONS
Roads impact urban kit foxes. Fox-vehicle collision was the primary cause of mortality over a six-year intensive study of urban fox ecology. Because of the absence of predators in the urban environment, it is unclear whether vehicle strike was a limited factor for fox population growth, or simply a compensatory source of mortality for animals that would have been depredated had predator populations been robust. Analyses of survival and population viability are pending. Fox-vehicle collision spiked during the December reproductive season for male kit foxes. This spike in mortality may disrupt kit fox reproductive ecology by destabilizing pair bonds directly prior to whelping and rearing of young. Fox-vehicle collisions occurred more frequently than expected within one road width of an intersection with a linear right-of-way. Rights-of-way may be natural crossing locations for foxes due to habitual travel patterns. They also may be difficult to navigate safely due to wider roadways and irregular traffic speeds and directions. Kit foxes denned on roadsides at similar densities to more remote locations. Likewise, fox movements did not appear overtly affected by roads. Our study, however, was not specifically designed to test for an impact of roads on fox home range and dispersal patterns. An impact on either of these aspects of kit fox ecology is therefore unknown.
The effects of road construction and modification may be reduced by the installation of artificial dens and wildlife crossing structures as outlined in the appendix to this document. Efforts to conserve urban fox populations will contribute to the recovery of this endangered species. Because fox-vehicle collision is the primary source of mortality for urbanized foxes, changes to roads that decrease fox death should command a central role in future conservation programs.
23 Urban Roads and the Endangered San Joaquin Kit Fox
FUTURE RESEARCH
Based on the studies conducted to date by ESRP, further research and conservation efforts will benefit urban kit foxes. We have identified five topics for future investigation.
1) The factors that affect the suitability of urban habitats for kit fox are currently unknown. These factors may include road density, landuse (e.g., zoning), building density, and presence of refugia and/or corridors between habitat patches. A systematic census of kit fox in urban habitats (e.g., Bakersfield, Taft, Coalinga) using camera or hair traps is required to focus conservation and mitigation efforts in the areas that are of highest value. Previous urban fox research, while critical to identifying vital rates (births, deaths, migration), was not designed to rigorously test the variables that affect fox presence. Therefore, there is a significant data gap in this area.
2) Cause of death could not be determined for a number of foxes, and poisoning was strongly suspected in many of these cases. This question warrants further investigation to identify the types and sources of poisoning. 3) A recent pilot study has indicated that striped skunks, which are a host to rabies in the San Joaquin Valley, may present a future epidemiological threat to kit foxes in urban environments. Further research is required to quantify this threat and develop strategies to ameliorate it.
4) Conservation strategies have been identified that could potentially benefit urban kit foxes, such as road crossing structures, artificial dens, passages through walls and fences, and the construction of refugia and corridors in urban landscapes.
Further research on the efficacy of these strategies, and information packages detailing these strategies, would benefit urban kit foxes, city planners, and developers.
5) A recent survey indicated that Bakersfield residents harbored misconceptions regarding kit foxes and their population status (Bjurlin and Cypher, in press).
Resources directed toward developing and evaluating a coordinated outreach effort will benefit kit fox conservation in both urban and natural environments. 24 Urban Roads and the Endangered San Joaquin Kit Fox
LITERATURE CITED
Bjurlin, C.D., and B. L. Cypher. 2003. Effects of roads on San Joaquin Kit Foxes: A review and synthesis of existing data. Pages 397-406 in C.L. Irwin, P.Garrett, and K.P.McDermott, editors. 2003 Proceedings of the International Conference on Ecology and Transportation. Center for Transportation and the Environment, North Carolina State University, Raleigh, NC.
Bjurlin, C.D., and B. L. Cypher. In Press. Encounter frequency with the urbanized San Joaquin kit fox correlates with public beliefs and attitudes toward the species.
Endangered Species Update.
City of Bakersfield. 2000-2004. Geospatial data on roads and traffic volumes from Department of GIS and Traffic Engineering. http://www.bakersfieldcity.us/ Cypher, B. L., and K. A. Spencer. 1998. Competitive interactions between coyotes and San Joaquin kit foxes. Journal of Mammalogy 79:204-214.
Cypher, B.L. 2000. Effects of roads on San Joaquin kit foxes: a review and synthesis of existing data. Report for California Department of Transportation, Sacramento, California.
Cypher, B. L., G. D. Warrick, M. R. M. Otten, T. P. O’Farrell, W. H. Berry, C. E. Harris, T. T. Kato, P. M. McCue, J. H. Scrivner, and B. W. Zoellick. 2000. Population dynamics of San Joaquin kit foxes at the Naval Petroleum Reserves in California.
Wildlife Monographs 145. 43pp.
ESRI Inc. 1996. Arcview 3.2 for Windows. ESRI Inc., Redlands, CA.
Murdoch, J. D. 2004. Scent marking behavior of the San Joaquin kit fox (Vulpes macrotis mutica). M. S. Thesis. University of Denver, CO.
Ralls, K, and P. J. White. 1995. Predation on San Joaquin kit foxes by larger canids.
Journal of Mammalogy 76:723-729.
SPSS Inc. 2002. SPSS Base 10.0 for Windows User's Guide. SPSS Inc., Chicago IL.
Trewhella, W.J., and S. Harris. 1990. The effect of railway lines on urban fox (Vulpes vulpes) numbers and dispersal movements. J. Zool., Lond. 221:321-326 United States Fish and Wildlife Service. 1998. Recovery plan for upland species of the San Joaquin Valley, California. United States Fish and Wildlife Service, Region 1, Portland, Oregon. 319 pp.
White, P. J., W. H. Berry, J. J. Eliason, and M. T. Hanson. 2000. Catastrophic decrease in an isolated population of kit foxes. The Southwestern Naturalist 45:204-211. 25 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox APPENDIX. SUPPLEMENTAL RECOMMENDATIONS
FOR PROTECTION OF SAN JOAQUIN KIT FOX DURING
ROAD PROJECTS IN URBAN ENVIRONMENTS
Prepared by: Endangered Species Recovery Program
in cooperation with: U.S. Fish and Wildlife Service, Sacramento Field Office and the California Department of Transportation
July 2005
INTRODUCTION
The San Joaquin kit fox (Vulpes macrotis mutica) was listed as Federally Endangered in 1967 and California Threatened in 1973. Specific measures implemented to protect the kit fox for any given project shall be determined by the U.S. Fish and Wildlife Service (Service) based upon applicant consultation with the Service. The purpose of this document is to provide an introduction to measures that may reduce impacts of road construction or modification in urban environments. Specifically, we discuss the criteria for and construction of artificial dens and road crossing structures. The measures outlined in this document are supplemental to standard Service and Caltrans guidelines, which will not be repeated here. Furthermore, these procedures are subject to modification or revision at the discretion of Service. The recommendations made in this appendix are those of the authors and are based on the findings of this research project and other current knowledge of the San Joaquin kit fox. These procedures are applicable to all urban environments where kit foxes are present or will be present in the future. Kit fox presence has been confirmed in Bakersfield, Taft, Santa Nella, and Coalinga, but surveys have yet to be conducted elsewhere. Kit foxes are likely to be found now or in the future in other urban or urbanizing areas.
DEN DISTURBANCE
Summary
Dens are a vital resource to the kit fox in urban environments (Koopman et al. 1998).
Dens provide refuge from predators and climatic extremes, and a location to whelp and rear young. Urban kit foxes typically occupy dens diurnally, but may spend considerable time within dens during the night, especially immediately preceding parturition and in the months post-parturition when young are nursing and vulnerable to predation. In the following text we describe kit fox dens in urban environments and make recommendations for the treatment of dens when they are encountered at a work site. In addition, we provide criteria and instructions for the creation of fox-specific artificial 26 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox dens. The construction of artificial dens may in some cases offset the destruction or disturbance of dens or fox habitat during road projects.
Urban Kit Fox Den Description
Many Federal guidelines pertain to the “known den” (U.S. Fish and Wildlife Service 1999). A known den is defined as any existing earthen den or manmade structure that is used or has been used at any time in the past by a San Joaquin kit fox. Evidence of use may include historic records, past or current radio telemetry or spotlighting data, kit fox sign such as tracks, scat, and/or prey remains, or other reasonable proof that a den or structure is being or has been used by a kit fox. The U.S. Fish and Wildlife Service discourages use of the terms ”active” and “inactive” when referring to a kit fox den because occupied dens may show no evidence of use, and because kit foxes change dens often, with the result that the status of a given den may change frequently and abruptly.
Known dens in urban environments take a variety of forms. Most dens are earthen and have multiple entrances, occur in vacant or undeveloped lots, and appear similar to dens found in natural lands. Many earthen dens in urban environments, however, occur at atypical locations, such as dense landscaping, maintained lawns, building foundations, stacked materials, and canal, drainage basin, road or railroad embankments (Figure 14a-d).
Kit fox use of manmade structures presents a further complication when assessing fox presence in urban environments. Kit foxes regularly den within pipes, under storage containers, buildings with raised foundations, stacked materials, vehicles, or any other structure or object that offers shelter and is large enough for a fox to enter (Figure 15a-d).
Manmade structures may be permanent or temporary and may be occupied by kit fox for a single night or habitually. There may be little or no indication that a fox is present at the site. Because these features often are large and provide shelter without digging, typical sign of fox presence, such as dirt mounds, prey remains, or tracks, may be absent or obscured.
Detection and evaluation of kit fox dens in urban environments is challenging. Access to affected or adjacent properties may be restricted at the time of surveying. Irrigation associated with landscaping may degrade dirt mounds, prey remains, and tracks. In some cases dense thatch entirely obscures den entrances (Figure 16a-c). All potential earthen and manmade structures should be thoroughly inspected for sign of kit fox occupancy. In addition to standard procedures, the use of track plates and/or fiber-optic burrow probes may be necessary. Lastly, it is recommended that the surveying biologist interview local landowners, employees, and passersby about kit fox presence, den occupancy, and historic use of a potential project site. Local citizens often will have useful information on kit fox activity and habits that can focus survey efforts.
Natal dens, or dens where whelping and rearing of young occur, present a special circumstance that warrants increased protection. If a natal den is detected within or adjacent to the project site, all activities should immediately stop and the appropriate authorities should be notified. Natal dens typically have more entrances, tracks, scat, prey remains, and human garbage, and may have a broader apron of matted dirt and/or vegetation at one or more entrances (Figure 14b). As with non-natal dens, they may occur 27 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox in a wide range of circumstances, from earthen dens more typical of natural lands to manmade structures where presence of the family group is difficult to confirm without direct observation of young. If interviewed, local citizens often will provide detailed information on the whereabouts and historic use of natal dens.
Artificial Den Description
Every effort should be made to avoid destroying or damaging known dens during project activities, as per standardized recommendations by U.S. Fish and Wildlife Service (e.g., surveys, monitoring, and exclusion zones; U.S. Fish and Wildlife Service 1999). Den destruction may at times be unavoidable. Consultation must occur prior to disturbance or destruction of den sites. While careful excavation may reduce the potential for direct mortality, loss of den sites has long-term negative effects that reduce the quality and viability of urban environments for kit fox.
The construction of artificial dens is a recommended mitigation for the disturbance or destruction of earthen or manmade kit fox dens during project activities. Artificial dens are of two types: subterranean and escape. Subterranean dens consist of two entrance tunnels (3-m length of 20-cm diameter polyvinyl chloride or high-density polyethylene pipe) leading down at no more than a 30-degree angle to a subterranean chamber (0.5 m in diameter, 0.3 m tall). Entrance tunnels should be oriented such that water does not flood the chamber. It is also recommended that a longitudinal section of the tunnel floor be removed to increase drainage and provide better footing for foxes that are exiting the chamber. The floor of the chamber should be located approximately one meter below ground. The chamber may be either box- or dome-shaped, but must have an earthen floor that allows kit foxes to enlarge the den over time (Figure 17a-d).
Escape dens consist of 3- to 6-m lengths of 20-cm diameter pipe (polyvinyl chloride or high density polyethylene) placed on the surface of the ground and covered with 1-2 m of soil (Figure 18a-d).
Both subterranean and escape dens can be modified to exclude entrance by larger predators, particularly red foxes (Vulpes vulpes) and coyotes (Canis latrans). These predators could be excluded by narrowing the den entrances to a width of 10-15 cm. This can be accomplished in a variety of ways, such as driving stakes in front of the entrances, or installing prefabricated diameter-reduction couplings.
Artificial subterranean and escape dens are regularly used by kit foxes in urban environments for resting, predator avoidance, avoiding temperature extremes, moisture conservation, and rearing of young. From June 2001 to June 2004, 22 subterranean and 9 escape dens in urban Bakersfield, CA were monitored using tracking media, remotelytriggered cameras, and radio telemetry (Cypher et al., unpublished data). Kit foxes used 29 of the 31 dens during the study period. These dens were checked with tracking media 8548 times, and fox tracks were detected on 1198 occasions (14%). This rate of visitation was a minimum estimate because precipitation, irrigation, and visitation by other animals at times made detecting kit fox tracks difficult. In spring 2003, and again in spring 2004, two different family groups raised young in artificial subterranean dens (Figure 19a-b).
28 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Artificial Den Installation Criteria
The following criteria should be met when selecting locations to construct artificial dens. 1) Artificial dens should be as close as possible to the destroyed or disturbed fox den. 2) The location should have a high likelihood of kit fox visitation. 3) Den entrances should be oriented to avoid flooding.
4) The den complex should have reduced likelihood of future disturbance, including development, regular maintenance, and human tampering.
Permanent cautionary devices that alert maintenance personnel to the presence of the artificial den may allow construction in regularly maintained areas. If a suitable site is unavailable along the road corridor it may be necessary to arrange for cooperative agreements with adjacent landowners to install artificial dens on their properties.
Suitable properties may include railway, canal, or utility corridors, drainage basins, golf courses, parks, and industrial sites. Throughout the site selection and construction process, the suitability for kit fox, the expected longevity, and the impacts on regular maintenance activities should be carefully evaluated.
KIT FOX ROAD CROSSING STRUCTURES
Summary
Vehicle strike is the leading cause of mortality for urbanized kit foxes. The likelihood of strike increases with increasing road width, speed limits, and traffic volume. Strikes often occur at the intersection of roads with linear rights-of-way. Linear rights-of-way include other roads (of all sizes), railroads, canals, utility corridors, golf course crossings, and riparian areas. Kit foxes appear to use linear corridors for movement, potentially accounting for the increase in strikes at these locations.
Major roads and associated features may restrict fox movements and consequently reduce gene flow, dispersal, colonization of habitat patches, and the resilience of fox populations to disturbance. This is especially likely in urban environments where road density, width, and traffic volume are increased and habitat is fragmented and susceptible to change.
Maintaining connectivity is identified as a primary recovery action for kit fox in section II.L.6.a. of the Recovery Plan for Upland Species of the San Joaquin Valley, California (U.S. Fish and Wildlife Service 1998).
The construction of fox-specific road crossing structures is a recommended conservation strategy for new high-volume roads, the widening of existing roads, or the rebuilding of existing structures that have the potential to facilitate kit fox road crossings. Potential crossing structures include underpasses, overpasses, and culverts. In the following text we describe crossing structures for urbanized kit foxes and provide criteria for site selection and instructions for building or modifying structures.
Road Crossing Structure Attributes
Little is known about the attributes that make crossing structures appealing to the San Joaquin kit fox. Clevenger (2005) conducted a comprehensive literature review on the 29 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox subject, but his conclusions suffered from a lack of data specific to kit fox. To fill this gap, Cypher et al. (Interagency Agreement No. 43A0068) have initiated a 2005-2006 study for California Department of Transportation to evaluate non-engineered crossing structures along 4-lane highways within the range of the San Joaquin kit fox and the ecologically similar desert kit fox of the Mojave eco-region. While these data will be useful when they become available, they will have limited applicability to kit fox crossing structures in urban environments.
Urban habitats are highly fragmented, and urban kit foxes develop habitual travel behaviors, often utilizing linear corridors for movement through the complex of human polygonal and linear development. In contrast, the Cypher et al. 2005-2006 study will examine crossing structures on roads that transect native habitat. There is no evidence that kit foxes in natural lands concentrate road crossings at specific features, such as drainage culverts, bridges, or road intersections when medians, fencing, or other impediments are absent.
In a recent study of the effects of two-lane highways on San Joaquin kit fox in natural lands (LoKern), Cypher et al (Interagency Agreement No. 06A0814, 55004872) found no evidence of fox avoidance of highways or of favored crossing locations. It should be noted, however, that traffic volumes on the highways in the LoKern study (approximately 8500 vehicles per day) were similar to volumes found on local roads in the city of Bakersfield (this study). Neither highways at LoKern nor local roads at Bakersfield significantly contributed to kit fox mortality. In other words, there may be little benefit to utilizing crossing structures or other habitual crossing locations when there is little risk of strike.
The following recommendations are based on knowledge of kit fox behavior, movements, territory use, and locations of mortality. We have combined these data with general recommendations on structure design and site selection for similar species.
Ideally, crossing structures in urban environments shall be institutionally linked with long-term monitoring programs and clear criteria for determining efficacy.
On the most basic level a crossing structure should satisfy two conditions. First, it should reduce mortality for the target species. Because vehicle strike is the primary cause of death for kit foxes in urban lands, and strikes occur disproportionately on major roads at identifiable geographic features (i.e., intersections with linear rights-of-way), we conclude that crossing structures have a high probability of reducing mortality.
Consequently crossing structures are an appropriate and necessary mitigation for urban road projects.
Second, crossing structures should increase habitat connectivity. This is a more difficult condition to evaluate. As noted, urban habitats are highly fragmented. To the extent that roads, and especially high-volume roads, contribute to fragmentation, we conclude that successful crossing structures will increase connectivity. As demonstrated (this study), kit foxes have seasonally influenced behaviors and susceptibility to vehicle strike.
During the month of December, male kit foxes increase scent marking frequency (an indicator of territory defense) and movements in search of mating opportunities. Not surprising, there is an increase in vehicle strike for male kit foxes during this period of instability in social dynamics. Furthermore, kit fox juveniles disperse during summer months, sometimes several miles from the maternal range, again encountering many 30 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox roads. Finally, urban kit foxes are displaced by new development and other human activities, resulting in range instability and dispersal to new territories. It is not known, however, whether the presence and types of roads in the urban environment influence the direction and length of movements and dispersal.
We take a hierarchical approach, from landscape to individual behavior, in describing requirements of fox-specific crossing structures. Criteria include: 1) road type; 2) kit fox presence and adjacent habitat suitability; 3) presence of natural crossing locations; 4) embankments, walls, or fencing that funnel individuals toward the crossing zone; and 5) passage design that meets kit fox behavioral requirements. We stress that these criteria are generated with expert opinion and data from ongoing observational studies of urban foxes. Hypothesis driven experiments will be necessary to evaluate the relative importance of these variables.
Criterion 1: Road type
We examined the distribution of fox-vehicle collisions on four types of urban roads - highway, arterial, collector, and local. Of these, kit foxes disproportionately died on arterial roads. Arterial roads typically were wider and had higher posted speed limits and traffic volumes than collector and local roads. Foxes also died on collector roads in Bakersfield from 1985-2004. In some cases, collector roads had similar traffic volumes and widths to arterial roads. Highways, which had the highest traffic volumes and speed limits, weren’t a marked source of fox mortality during this study. The absence of foxvehicle collision on highways can be explained by a barrier effect –animals that do not attempt to cross, will not be struck. Dispersal of individuals between habitat fragments, however, is an essential function of kit fox populations (U.S. Fish and Wildlife Service 1998) and a reduction in dispersal due to roads has been shown to strongly impact the demographics and extinction probability of small populations (Jaeger and Fahrig 2004).
Therefore it is likely that highways posed a significant road effect (if not direct mortality) on urbanized foxes. Lastly, there was little evidence for an association between local roads and fox-vehicle collision or altered kit fox movements.
Based on these findings, we recommend that crossing structures be considered on all highway, arterial, and collector roads. We do not recommend crossing structures as a protection or compensation measure for local roads.
Criterion 2: Kit fox presence and adjacent habitat suitability Presence of kit foxes may be evaluated by spotlighting, surveillance or track stations, surveying for scat, tracks, and dens, or interviewing citizenry. Presence/absence data, however, may be fallible to some degree. Kit foxes may be absent not because the site is unsuitable, but because of localized extirpation. In fact, fox populations throughout the species’ range undergo cycles of extirpation and recolonization, known as metapopulation dynamics (U.S. Fish and Wildlife Service 1998). Metapopulation dynamics influence kit fox demographics and extinction probability, and increase in strength with increasing fragmentation. Furthermore, it has been shown that with growing isolation of habitat fragments, it is less likely that fragments will be recolonized in the event of local extinction. Nowhere is kit fox habitat more fragmented and more 31 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox frequently altered than in urban environments. Therefore, it is likely that at any given time a subset of suitable habitat in urban environments will be unoccupied by kit fox.
A conservative alternative to presence/absence surveys is to concentrate crossing mitigation at locations that have suitable adjacent habitats. As a general rule urban kit foxes occupy industrial and commercial lands, parks, golf courses, and schools. Within these lands, occupancy appears linked to the extent of contiguous habitat, the quantity of undeveloped or lightly developed lots, the presence of drainage basins (favored den sites), and the presence of linear features that provide den building and movement opportunities such as canals, utility corridors, railroads, and riparian areas. Kit foxes do not typically occupy residential zones unless a golf course or other large open space is present (in which case occupancy is highly likely).
Criterion 3: Areas of increased road crossing
Clevenger (2005) reports that animal use of a crossing structure is linked to placement near natural crossing points. This assessment is supported by crossing studies (e.g., Foster and Humphrey 1995, Yanes 1995). Urban kit foxes more often are killed in vehicle strikes at the intersection of major roads with linear rights-of-way including other roads (of all types), canals, railroads, utility corridors, and riparian areas (this study). The concentration of mortalities at these intersections increases the likelihood of successful mitigation. First it narrows the selection of sites for crossing structures to easily identifiable landscape features. Second, it decreases the need to inhibit crossing at other locations. Third, intersections with linear rights-of-way often have pre-existing crossing structures. For example, a bridge over a canal or river may only require a design modification to be suitable for kit fox. When implemented early in the planning process these modifications may have little additional cost.
Because of the concentration of road crossings and vehicle mortalities at linear rights-ofway, we recommend that mitigation efforts prioritize these locations. For practical reasons, it will not be possible to install crossing structures at most road-road intersections. Instead, we recommend placing highest priority on installing or modifying structures at intersections of roads with highways, railroads, canals, rivers, or utility corridors and other locations where an underpass, overpass, or culvert is required.
Criterion 4: Embankments, walls, and fences
Another important predictor of use of crossing structures and decrease in vehicle strikes is the construction of manmade barriers that funnel animals toward the passageway (e.g., Haas 2000, Clevenger 2005, Mata et al. 2005). Barriers may include embankments, walls, and fences.
Embankments appear to discourage road crossing. Cypher et al. (in prep.) observed regular use by kit foxes of a railway underpass on a raised portion of highway 99 in Bakersfield (Figure 20a). The embankment was approximately eight meters tall and the underpass span was approximately 50 meters wide. Radio-tagged foxes were never known to climb the embankment to travel across the highway surface. Kit foxes constructed dens in the earthen slopes within the underpass and even whelped and reared young at the site for multiple seasons (Figure 20b). Embankments on raised highways 32 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox may fragment the landscape in the absence of underpasses or other crossing opportunities. Crossing structures should always be considered when building or modifying raised roadways.
Most urban roads are at grade with the surrounding environment. Cement walls may border highways, arterial, and collector roads, but this is typical only of residential areas, which may not be suitable for kit fox. Other roads are bordered by vegetation, low walls, and metal or wood fencing, all of which may be permeable to kit foxes. Small, skilled at digging, and agile, the kit fox is adept at passing through barriers designed for humans or other large mammals.
We recommend the installation of walls at potential crossing sites that encourage use of the passage and discourage crossing the road above grade. Studies on other species suggest that barriers are more effective when they are shaped as a funnel that directs animals toward the structure. It also is recommended that there be a method of exit for animals that get onto the roadway within the barrier zone. The complexity of urban environments makes meeting these recommendations difficult. Nevertheless, barriers are an integral part of successful crossing structures and should be implemented with all crossing projects.
We make the following specific recommendations. Barriers should be approximately 1.5 meters in height and of a solid material, such as cement block, that discourages climbing.
Walls should be impermeable to kit foxes that approach from adjacent habitat, but permeable to foxes that are on the roadway. One method to achieve one-way permeability is to install a dirt embankment next to the wall on the side nearest the road that allows a fox to run to the top of the wall from roadside (Figure 21a-b). The wall should remain 1.5 meters above grade on the side that borders habitat to prevent entrance to the roadway. Based on behavioral observations of radio-collared kit foxes and location of kit fox mortalities (this study), barriers should lead directly from the passage and run parallel to the road for a distance of at least 50 meters. In some cases, barriers will best be implemented as part of and in addition to existing natural or manmade features, including embankments, walls, and buildings. Finally, landscaping is recommended between the barrier and roadside (i.e., on the embankment). Urban kit foxes are known to use landscaping for cover while traveling along arterial roadways that are bordered by cement block walls (C. Bjurlin, pers. obs.).
Criterion 5: Behaviorally suitable passage design
We have identified four characteristics that affect behavioral suitability of crossing structures for kit foxes. First, a clear line of sight should be maintained through the passage for the entire breadth of the roadway, with the exit visible from the entrance.
Second, approach to the entrances should be level or gently sloped and free from vegetation or obstacles. Third, the passage should be minimally one meter square, with passage dimensions proportional to the roadway (i.e., as road width increases, passage width and height increases). Fourth, one escape den (see above) should be installed within the passage and one escape den installed on the approach to each entrance to give kit foxes protection from predators. In the following text, we profile existing structures to illustrate the aforementioned criteria. We provide recommended modifications where appropriate.
33 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Profiled Crossing Structures
Seven Oaks Golf Course underpass
The Seven Oaks Golf Course in Bakersfield, CA was bisected by Buena Vista road, a four-lane, divided arterial road (Criterion 1). The road segment of interest (980 m) was bounded to the north by intersection with Ming Avenue and to the south by intersection with Chamber Blvd. Traffic volumes were estimated in 2002 at 13,750 vehicles per day (vpd). To maintain connectivity for golfers, an underpass structure was installed. This underpass met nearly all of the criteria for a successful crossing structure. The golf course was occupied by kit foxes and extended on both sides of the passage (Figure 22, Criterion 2). The greens narrowed where they approached the crossing site, creating a natural transverse point (Criterion 3). Two-meter high walls bordered the road (Criterion 4). The passage was greater than two meters square and had flanged and unobstructed entrances (Figure 22b-c, Criterion 5). One confirmed vehicle strike occurred at the site after construction of the barrier wall (Figure 22a). There were gates in the walls at a maintenance yard directly southeast of the passage and at a road access point to the southwest of the passage. A kit fox may have used one of these gates to gain access to the roadway.
Analysis - This design was suitable for locations with pedestrian or bicycle routes, utility corridors, golf courses, or other linear rights-of-way that are not associated with water transport. It would be improved by the installation of escape dens and the modification of the nearby gates to prevent kit foxes from entering the roadway.
Truxtun Extension horse culvert
Truxtun Extension was a 4-lane, divided collector road in Bakersfield, CA (Criterion 1).
Traffic volumes in 2002 were estimated at 35,000 vpd. The road segment of interest (5.3 km) occured between the intersection with Wible Road to the east and Coffee Road to the west. The segment was bordered to the north by the Kern River and to the south by a canal and mixed residential and commercial zones. Kit foxes occupied the surrounding lands. Radio-tagged animals repeatedly crossed the road and five confirmed vehicle strikes occurred along the road segment (this study). An underpass culvert was built 270 m east of the junction with Coffee Road. The passage location had suitable habitat to the north (Criterion 2). A pedestrian trail connected the passage to a canal on the southern side of the roadway (Figure 23a-b, Criterion 3). There was a chain link fence that may have impeded access to the road on the southern side, but it was broken by a pedestrian trail 15 m to the west of the southern entrance. The northern entrance had a 20-m chain link fence directly over the culvert (Figure 23c). The road was easily accessible from the north along the remainder of the segment. The culvert was approximately 2.5 meters in diameter with an earthen bottom that was seasonally flooded (Figure 23d, Criterion 5). On one occasion a kit fox was seen running north across the road directly over the crossing structure.
Analysis – This was a suitable passage at an appropriate location that required fencing and escape dens to become fully operational.
34 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Coffee Road bicycle path underpass
Coffee Road was a six-lane, divided, arterial road in Bakersfield, CA (Criterion 1).
Traffic volumes in 2002 were estimated at 45,100 vpd. The road segment of interest (1600 m) was bounded to the north by intersection with Brimhall Road and to the south by intersection with Stockdale Highway. Surrounding lands were a mixture of commercial and undeveloped properties and were suitable for kit fox (Figure 24a, Criterion 2). Several canals and the Kern River corridor intersected the road. A bridge that spaned the Kern River also provided passage for a bicycle path on the southern embankment. The river corridor, proximity to road and canal intersections, and presence of a bicycle path made the passage a natural crossing point (Criterion 3). The west side of Coffee Road was bounded by chain link fence, but the east side had open access to the roadway (Figure 24b-c, Criterion 4). The passage was greater than 3m in height and width, and free from obstruction (Figure 24d, Criterion 5). Five confirmed vehicle strikes occurred on the road segment, including one that was 60 m south of the passage (Figure 24a & d).
Analysis – This was a suitable passage under a road with high traffic volume that required fencing and escape dens to become fully functional.
Highway 58 canal bridge
Highway 58 was a four-lane, divided roadway (Criterion 1). The road segment (2200 m) was bounded to the east by intersection with Landco Drive and to the west by intersection with Patton Way. Traffic volumes in 2004 were estimated at 47,000 vpd. Surrounding lands were a mixture of commercial, industrial, and undeveloped properties. A canal and arterial road (Fruitvale Ave) formed a six-way intersection with Highway 58. Kit foxes and their habitat were abundant along the road segment (Figure 25a, Criterion 2). The confluence of canal, arterial road, and highway made it a natural kit fox crossing location (Criterion 3). Chain link fence occured sporadically along the canal, but gaps in the fence and at gates allowed foxes to gain access to the roadway. The road was not walled or fenced. This underpass complex was composed of two separate bridges, one on Fruitvale Ave, the other on Highway 58. The Fruitvale Ave. bridge was impassable at the time photos were taken. The canal was transporting water and there was no embankment along its margin beneath the bridge (Figure 25b). In contrast, the Highway 58 bridge remained passable while transporting water. There were dirt embankments on both margins of the canal beneath the bridge, along with unobstructed entrance and exit locations (Figure 25c-d, Criterion 5). No fox-vehicle collisions were recorded at the location, but kit foxes frequently crossed the road during a telemetry study (Figure 25a).
A radio-tagged kit fox was repeatedly tracked to the canal and twice tracked to the canal underpass when there was no water present.
Analysis - The confluence of multiple linear rights-of-way along with presence of kit foxes and frequent road crossings made this an appropriate location for a crossing structure. The fencing at the site was insufficient for keeping foxes off the roadway.
When transporting water, one of the bridges did not accommodate fox movement beneath the roadway. This location would require extensive modification to be fully functional. 35 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 14. Earthen kit fox dens in urban Bakersfield, CA. a) Single entrance den under building foundation. b) Natal den complex on canal bank. c) Multi-entrance den in drainage basin bordering intersection of two arterial roads. d) Single entrance den in vacant lot. 36 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 15. Non-earthen den locations for kit foxes in Bakersfield, CA. a) Fox emerging from stacked pipe. b) Narrow entrances to a kit fox den under a storage container. c) Fox resting beside stacked lumber at a construction site. d) Fox returning to a den within a modular housing unit.
37 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 16. Camouflaged earthen kit fox dens in urban Bakersfield, CA. a) Entrance to den in landscaping at parking lot. b) Thatch covered den entrance in a golf course fairway. c) Dirt mound from den in shrub-island at park. 38 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 17. Artificial subterranean dens for San Joaquin kit fox at Bakersfield, CA. a) Artificial den schematic. b) PVC two-entrance chamber den under construction. c) High-density polyethylene two-entrance den. d) PVC tunnel with floor removed longitudinally. 39 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 18. Artificial escape dens for San Joaquin kit fox at Bakersfield, CA. a) Escape den schematic. b) High-density polyethylene escape den under construction. c) Completed den. d) Kit fox entering escape den. 40 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 19. Kit fox pups at artificial subterranean dens at a golf course (a) and drainage basin (b) in Bakersfield, CA. Figure 20. Railroad underpass on highway 99 in Bakersfield, CA. a) Habitat view. b) Kit fox natal den at the top of the underpass embankment.
41 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 21. Barrier wall to encourage use of road crossing structures for the San Joaquin kit fox in urban environments. The roadside embankment allows foxes that are trapped on the roadway to clear the barrier wall. a) Cross-section view. B. Three-dimensional rendering.
42 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 22. Buena Vista Road golf cart crossing structure, Bakersfield, CA. a) Aerial view of roadkill and radio-tagged kit fox locations at crossing structure. b) Habitat view from east entrance of crossing structure. c) Approach view to east entrance. d) Passage interior. 43 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 23. Truxtun Extension horse culvert, Bakersfield, CA. a) Aerial view of radio-tagged kit fox locations at horse culvert. b) View from pedestrian trail at south culvert entrance (canal in background). c) North culvert entrance. Yellow line depicts extent of fencing on north side of road. d) Culvert interior. 44 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 24. Coffee Road overpass at Kern River bicycle trail, Bakersfield, CA. a) Aerial view of kit fox roadkill and radio-tagged night locations at crossing structure. b) Habitat view from west entrance. c) East entrance to bicycle path on southern embankment of Kern River. d) View of roadway from East with location of kit fox roadkill in red. No fences prevent fox access to roadway on eastern side. 45 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox Figure 25. Highway 58/Fruitvale Avenue canal bridge, Bakersfield, CA. a) Aerial view of radio-tagged kit fox night locations at crossing structure. b) East entrance to Fruitvale Bridge obstructed by water. c) South entrance to highway 58 bridge. d) Dirtembankment under Highway 58 Bridge. 46 Appendix A. Supplemental Recommendations for Protection of San Joaquin Kit Fox
LITERATURE CITED
Clevenger, A.P. 2005. Design and performance of wildlife crossings for kit foxes and ecologically similar small carnivores: A literature review and semi-annotated bibliography. California Department of Transportation, San Luis Obispo, California.
Foster, M.L., and S.R. Humphrey. 1995. Use of highway underpasses by Florida panthers and other wildlife. Wildlife Society Bulletin 23, 95-100.
Haas, C.D. 2000. Distribution, relative abundance, and roadway underpass responses of carnivores throughout the Puente-Chino Hills. MSc thesis, California State Polytechnic University, Pomona.
Jaeger, J.A., and L. Fahrig. 2004. Effects of road fencing on population persistence. Conservation Biology 1651-1657.
Koopman, M. E., J. H. Scrivner, and T. T. Kato. 1998. Patterns of den use by San Joaquin kit foxes.
Journal of Wildlife Management 62:373-379.
Mata, C., I. Hervás, J. Herranz, F. Suárez, and J.E. Malo. 2005. Complementary use by vertebrates of crossing structures along a fenced Spanish motorway. Biological Conservation 124, 397-405.
U.S. Fish and Wildlife Service. 1998. Recovery plan for arid upland species of the San Joaquin Valley, California. U.S. Fish and Wildlife Service, Portland, Oregon.
U.S. Fish and Wildlife Service. 1999. Standardized recommendations for protection of the San Joaquin kit fox prior to or during ground disturbance. U.S. Fish and Wildlife Service, Sacramento, California.
Yanes, M., J.M. Velasco, and F. Suárez. 1995. Permeability of roads and railways to vertebrates: the importance of culverts. Biological Conservation 71:217-222. 47 View publication stats
SAN JOAQUIN KIT FOX HOME RANGE, HABITAT USE,
AND MOVEMENTS IN URBAN BAKERSFIELD
by
Nancy Frost
A Thesis
Presented to
The Faculty of Humboldt State University
In Partial Fulfillment
Of the Requirements for the Degree
Master of Science
In Natural Resources: Wildlife
December 2005
iii
ABSTRACT
San Joaquin kit fox home range, habitat use, and movements in urban Bakersfield Nancy Frost
Habitat destruction and fragmentation has led to the decline of the federally endangered and state threatened San Joaquin kit fox (Vulpes macrotis mutica). Kit foxes in the San Joaquin Valley occur in and adjacent to several urban areas. The urban kit fox population in Bakersfield has the potential to contribute to recovery efforts, however, little is known about habitat use in the urban environment. Habitat use in the urban landscape was examined in 28 radiocollared adult kit foxes between 1 May 1997 and 15 January 1998.
The area of the urban environment needed to meet kit foxes’ ecological requirements varied among the sexes and fluctuated throughout the year. Mean home range size was 1.72 km2 (100% minimum convex polygon estimate) and mean concentrated use area (core area; 50% fixed kernel estimate) size was 0.16 km2. Females had a greater median number of core areas than did males, but core area size did not differ between the sexes. Mean home range size was significantly larger during the dispersal season than during the pair formation and breeding seasons. Home range size was greater for males than females during the breeding season.
To assess the extent to which kit foxes were concentrated around limited resources, the percentage of overlap between adjacent kit foxes’ home ranges and core areas was determined.
Mean home range overlap was greater than 71% for family group members and less than 16% for unrelated individuals, which was less than that reported for the nearby rural population. Overlap of adjacent kit foxes’ core areas indicated that kit foxes were concentrated around key urban habitat patches. Core area overlap was greater for members of the same family group than core area overlap of neighboring males and females or neighboring males. iv
To determine which attributes of the urban environment were used by kit foxes and may support the population over time, habitats used disproportionately were compared to what was available in home ranges and the urban landscape. Kit foxes used open and sump (water catchment basins) habitats more than their availability in both the home range area and study area. There was more open and sump habitat in home ranges than in the study area. Kit fox core areas contained a disproportionately high amount of sumps that had food and den sites and restricted public access.
Sump and open habitats were more suitable for denning and consequently, were used more than their availability in the study area. Kit foxes primarily used subterranean dens but also used pipes and other man-made structures. Dens were located farther from roads than expected and in habitat patches that were larger than the median habitat patch in the study area.
To identify which urban habitats kit foxes used for resting, foraging, and traveling, kit fox movements and travel paths through adjacent habitat patches were examined. Kit foxes moved an average speed of 1.33 km/h. Minimum speed for females was greatest from approximately 0330 - 0730 h and for males was greatest from approximately 1830 - 2230 h. Kit foxes used sump and open habitats for resting. Kit foxes also foraged in these habitats, as well as in transition and commercial habitats. Habitats used for traveling included manicured open and open habitats, in which total distance traveled per movement session was longest. Overall median speed was greatest in residential habitat. Kit foxes were observed crossing roads and using culverts and bridges to move under roads.
Demographic characteristics and weights of the kit foxes that were captured were used to assess habitat quality. Two of the 28 radiocollared kit foxes died during 6,036 days of active radiotransmitters. Radiocollared kit foxes had 15 litters, comprised of 2.8 + 0.45 (range = 1 – 7) pups. Urban kit fox weight was similar to that for rural kit foxes. v
The availability of sump and open habitats appeared to shape the distribution and abundance of the urban population. Therefore, retaining sump and open habitats throughout Bakersfield may promote the continued existence of the urban kit fox population. vi
ACKNOWLEDGEMENTS
I would like to thank all those who contributed to the successful completion of this research project, especially my advisor, Dr. R. T. Golightly, for sharing with me both his advice and expertise. In addition, I thank my other committee members, Drs. T. L. George and D. W.
Kitchen for their support and constructive comments that greatly improved the quality of this thesis. My thanks go out to my professors and fellow students at Humboldt State University who contributed greatly to my educational growth. I would like to thank the San Joaquin chapter of The Wildlife Society for the research grant and the Eureka Rotary Club and the Stockton Sportsmen's Club for scholarships.
I would like to thank the California Department of Fish and Game, especially M. Potter and R. Reed, for assisting with this project by providing a vehicle and hiring three scientific aids, T. Chilton, J. Storlie, and R. Siebdrath, whose hard work, dedication, and willingness to learn contributed immensely to this project. I appreciate the volunteer efforts of M. Otten, G. Warrick, B. Vanherweg, B. Cypher, J. Hinshaw, and K. Brown. I thank the Department of Energy, Chevron USA, and Enterprise Advisory Services, Inc., especially J. Killen and B. Cypher, for the loan of telemetry equipment, radio collars, kit fox handling equipment, and traps. I would also like to thank P. Hoffman from the City of Bakersfield Water Resources Department and A. Abe from the City of Bakersfield Recreation and Parks Department for arranging access to city sumps and parks, respectively. Furthermore, I wish to thank J. Tobar, with the City of Bakersfield's Management Information Services Department, for the City of Bakerfield geographic information system coverages. I thank Dr. C. Hammans of the Coffee Road Animal Hospital and D. Kroger from the California Living Museum for their generous participation in the successful rehabilitation of an injured kit fox pup. I wish to acknowledge the Bakersfield SPCA for vii
"rescuing" one of my study animals that made its way to the third story of a parking garage and could not find the exit. My thanks go to A. Sullivan, J. Redmond, and M. Cantrell of the Sundale golf course, D. E. Keith Trucking, and K. S. Fabrication for allowing access to their property for implementation of the study. I wish to acknowledge Kelly Pipe Company for their cooperative efforts in helping me retrieve a kit fox pup that went for an unexpected "ride" in one of their pipes that was delivered from Bakersfield to Santa Fe Springs, California.
Special thanks go to my husband, S. Telthorst, for his tremendous support, encouragement, and participation in this research project. Finally, I dedicate this thesis to S.
Telthorst and my late mother, S. Castle, whose support and lifelong example of patience, perseverance, and persistence imparted me with the skills necessary to pursue and fulfill my dreams.
The United States Fish and Wildlife Service, California Department of Fish and Game, California Department of Transportation, and Humboldt State University Institutional Animal Care and Use Committee (protocol #96/97.W.62) issued the necessary permits and memorandum of understanding for this project.
viii
TABLE OF CONTENTS
Page
ABSTRACT .........................................................................................................................iii ACKNOWLEDGEMENTS....................................................................................................vi LIST OF TABLES .................................................................................................................x LIST OF FIGURES...............................................................................................................xi LIST OF APPENDICES.......................................................................................................xii INTRODUCTION..................................................................................................................1 STUDY AREA ......................................................................................................................5 METHODS............................................................................................................................9 Trapping ....................................................................................................................9 Locations...................................................................................................................9 Home Range ............................................................................................................12 Habitat Use ..............................................................................................................15 Movements ..............................................................................................................17 Demographics..........................................................................................................19 RESULTS............................................................................................................................21 Trapping ..................................................................................................................21 Locations.................................................................................................................21 Home Range ............................................................................................................21 Habitat Use ..............................................................................................................23 Movements ..............................................................................................................30 Demographics..........................................................................................................42 ix
TABLE OF CONTENTS (CONTINUED)
DISCUSSION......................................................................................................................43 Demographics..........................................................................................................43 Locations.................................................................................................................45 Home range..............................................................................................................46 Habitat use ...............................................................................................................50 Movements ..............................................................................................................53 MANAGEMENT RECOMMENDATIONS...........................................................................57 REFERENCES.....................................................................................................................59 x
LIST OF TABLES
Table Page
1 Habitat types and their descriptions used to typify the urban setting and kit fox habitat use in Bakersfield, California from May 1997 to January 1998. ....................... 7 2 Home range (100% minimum convex polygon) and core area (50% fixed kernel) size for radiocollared kit foxes in Bakersfield, California from May 1997 to January 1998. .........................................................................................................24 3 Seasonal home range (100% minimum convex polygon) size for radiocollared kit foxes in Bakersfield, California from May 1997 to January 1998. ..............................25 4 Ranked radiocollared kit fox habitat use based on habitat availability at the study area and home range area scale, in Bakersfield, California between May 1997 to January 1998. Habitat types used similarly (p > 0.05) are grouped by column............28 5 Mean difference between the mean proportion of habitat available in the study area and kit fox home ranges (e.g., there was 16.7% less open habitat in the study area than within home ranges), and kit fox home ranges and core areas in Bakersfield, California between May 1997 to January 1998.......................................29 6 Influence of sex, movement session time, and their interaction on minimum, maximum, and mean speed and total adjusted distance moved for 10 radiocollared kit foxes in Bakersfield, California from May 1997 to January 1998. .....................................................................................................................36 7 Movement session time, type of movement, and habitat associations for radiocollared kit foxes in Bakersfield, California from September 1997 to January 1998. .........................................................................................................39 8 Rural kit fox and swift fox cause-specific mortality rates reported within their geographic range for comparison to that for urban kit foxes in Bakersfield, California from May 1997 to January 1998...............................................................44 9 Kit fox home range size reported within various habitats within their geographic range for comparison to home range size of urban kit foxes in Bakersfield, California from May 1997 to January 1998...............................................................47 xi
LIST OF FIGURES
Figure Page
1 The study area in Bakersfield, Kern County, California for investigations of kit fox habitat use from May 1997 to January 1998......................................................... 6 2 Behavior exhibited by directly observed kit foxes at independent daily locations (n = 2,087) in Bakersfield, California from May 1997 to January 1998.......................22 3 Percentage of home range overlap and core area overlap for pairs of radiocollared kit foxes in Bakersfield, California from May 1997 to January 1998. Vertical bars represent + 1 SE. .............................................................................................26 4 Mean percentage of each habitat type in the study area, which bounded the available habitat, and radiocollared kit fox home ranges (n = 27) and core areas (n = 58) in Bakersfield, California from May 1997 to January 1998. Different letters above the bars indicate a significant difference in habitat use versus availability. ............................................................................................................27 5 Mean number of passing vehicles, passing pedestrians, and people in the same habitat patch as radiocollared kit foxes at all daily locations (n = 4,824) in Bakersfield, California from May 1997 to January 1998. Vertical bars represent + 1 SE....................................................................................................................31 6 Number of dens used by radiocollared kit foxes in each habitat type in Bakersfield, California from May 1997 to January 1998............................................32 7 Percentage of available habitat in the study area compared to percentage of habitat used by radiocollared kit foxes for denning in Bakersfield, California from May 1997 to January 1998. .............................................................................33 8 Minimum speed per movement session for male and female radiocollared kit foxes in Bakersfield, California from September 1997 to January 1998. .....................35 9 Mean distance radiocollared kit foxes traveled in each habitat type in Bakersfield, California from September 1997 to January 1998. Vertical bars represent + 1 SE.......37 10 Mean speed radiocollared kit foxes traveled in each habitat type in Bakersfield, California from September 1997 to January 1998. Vertical bars represent + 1 SE.......38 xii
LIST OF APPENDICES
Appendix Page
A Sites of live-captured kit foxes, domestic cats, and opossums between May 1997 and January 1998 in Bakersfield, California..............................................................69 B Kit fox location data and estimates for home range size, core area size, and time to independence for 28 radiocollared kit foxes that were monitored between May 1997 and January 1998 in Bakersfield, California. ....................................................70 C Weight, hind foot, and ear measurements for captured adult, subadult, and pup kit foxes in Bakersfield, California between May 1997 and January 1998...................73 D Area-observation curves using the 100% minimum convex polygon home range for 27 kit foxes in Bakersfield, California from May 1997 to January 1998.................74 E The percentage of all radiocollared kit fox daily locations (n = 4,824) and passing vehicles documented in linear habitats during each hour in Bakersfield, California from September 1997 to January 1998......................................................75 1 INTRODUCTION
The kit fox (Vulpes macrotis) is the smallest North American member of the family Canidae, with an average weight of 2.1 kg for adult females and 2.3 kg for adult males in California (Morrell 1972). Kit foxes range throughout the western United States in shortgrass prairies and other arid areas (Whitaker 1998). The San Joaquin kit fox (Vulpes macrotis mutica; hereafter kit fox) was described by C. H. Merriam in 1902 (McGrew 1979) and is the largest California subspecies in skeletal measurements, body size, and weight (Grinnell et al. 1937). Kit foxes inhabit arid habitats with flat to sloping terrain (Morrell 1971).
The kit fox historically ranged in the San Joaquin Valley of California, north of Tracy, west to San Joaquin County, east to La Grange, Stanislaus County, and south to Kern County (Grinnell et al. 1937, Morrell 1975). In the early 1900’s, the kit fox population started to decline (United States Fish and Wildlife Service 1983), and by 1930, its range had been reduced by more than half, with the largest portion remaining in the southern and western parts of the San Joaquin Valley (Grinnell et al. 1937). In 1969, the kit fox was known to range from Los Banos, Merced County, east to White River, Tulare County, south to Kern County, and west to San Luis Obispo County (Morrell 1975). Currently, the largest remaining populations of kit foxes occur in western Kern County and in the Carrizo Plain Natural Area, San Luis Obispo County (United States Fish and Wildlife Service 1998).
In 1967, the San Joaquin kit fox was listed as a federally endangered subspecies (United States Department of the Interior 1967), and in 1971, it was designated a State threatened species (United States Fish and Wildlife Service 1998). The destruction and fragmentation of its native habitat has been a limiting factor that has led to the decline of the kit fox population (Knapp 1978, Spiegel 1996, United States Fish and Wildlife Service 1998). This habitat fragmentation 2 has been due mainly to agriculture, urban development, and oil production (Morrell 1975, Spiegel 1996, United States Fish and Wildlife Service 1998). In 1993, the San Joaquin Valley Biological Technical Committee estimated that only about 1 - 5% of the original habitat of the kit fox remained.
Kit foxes in the San Joaquin Valley occur in and adjacent to several urban areas including the cities of Taft (Zoellick et al. 2002), Tulare, Visalia, and Porterville (United States Fish and Wildlife Service 1998), and Bakersfield, where kit foxes have been observed throughout the city (Morrell 1975, Murphy 1992, Cypher and Warrick 1993, Bjurlin and Cypher 2003). Kit foxes are known to use the Kern River Parkway in Bakersfield (Murphy 1992, Beedy et al. 1992) for denning, foraging, and traveling, despite the fact that it is bounded on the north and south by urban and industrial development and receives intensive public recreation use (Beedy et al. 1992).
Additionally, urban kit foxes have been found to den close to human activities and structures (Murphy 1992), including water sumps (catchment basins) in and adjacent to urban development in Bakersfield (Stafford and Murphy 1992).
Urban habitats may be marginal for kit foxes, because the urban environment has a high level of disturbance and consists of a patchy mosaic of habitats (Morrell 1975). While urban developments negatively impact kit fox habitat, kit foxes may still survive in or near them if there are adequate den sites and prey base (United States Fish and Wildlife Service 1998). Positive attributes of urban habitats may include a constant source of water from sumps, canals, and lawn sprinklers (Murphy 1992) that could lead to a more stable prey population. While fewer natural predators, such as coyotes (Canis latrans) and bobcats (Lynx rufus), are found in the urban environment, domestic dogs (Canis familiaris) occur in greater abundance. Food may be available on a more consistent basis due to the presence of refuse, which constitutes part of the kit fox diet in Bakersfield (Murphy 1992, Cypher and Warrick 1993). Such use of human-derived foods suggests that kit foxes may be able to adapt to the urban setting. 3 Smaller canid species, such as coyotes and foxes, often do well in human-altered environments because they scavenge and forage individually on a variety of small food items and are able to utilize new food sources (Kleiman and Brady 1978). If kit foxes are adaptable enough to persist in urban environments, as are coyotes (Quinn 1995, Romsos 1998, Grinder and Krausman 2001) and red foxes (Vulpes vulpes; Harris 1977, Kolb 1984, 1986, Harris and Rayner 1986, Doncaster et al. 1990, Lewis et al. 1993, Sallee 1998, Kamler and Ballard 2002), the urban kit fox population could contribute to recovery efforts (Cypher and Warrick 1993). Urban kit fox populations could protect against extirpations in rural areas, and serve as a source of animals for reintroduction efforts (Cypher and Frost 1999). Favorable habitat features in urban areas also could serve as linkages or corridors between natural lands, which may minimize local extinction and genetic isolation of fox populations in fragmented habitats (United States Fish and Wildlife Service 1998, Wandeler et al. 2003).
It is important to understand how kit foxes use landscapes in all areas where they exist, including urban settings. Unfortunately, little is known about the urban kit fox population.
Morrell (1975) noted that a study should be conducted to gain a better understanding of kit fox ecology in areas other than natural habitat. As part of the recovery strategy in the San Joaquin Valley Multispecies Recovery Plan (United States Fish and Wildlife Service 1998), it was recommended that better demographic information be collected for kit foxes living in residential and industrial areas. The San Joaquin Valley Biological Technical Committee (1993) expressed concern that urbanization threatens the remaining kit fox habitat and listed several kit fox research needs including further studies of mortality rates and causes, diet, distribution, home range requirements, and movements. Due to the continual loss of natural habitat, more information on urban kit fox space use, movements, survival, and reproduction may contribute to their recovery (Cypher and Warrick 1993).
4 Canid home range size is influenced primarily by food abundance, and also food distribution and availability of adequate denning sites (Kleiman and Brady 1978). In order to understand the ecological factors that facilitate habitat use, it is important to identify the areas of concentrated use (hereafter core areas) within the home range (Samuel et al. 1985). Optimal habitat conditions for a species may be identified by evaluating if and how core areas are used disproportionately (Ables 1969). Core areas likely have dependable food sources and rest sites (Samuel et al. 1985) such as dens, the availability of which limits the presence of kit foxes (Golightly 1981, Spiegel et al. 1996). If kit foxes are concentrated around limited resources, the home ranges and core areas of adjacent kit foxes may have substantial overlap (Golightly 1981).
If sufficient food and den sites are available, mortality is minimal, and reproduction occurs at reasonable rates, then urban habitat should support viable kit fox populations. The goal of my project was to determine which attributes of the urban environment were successfully used by kit foxes and may support the population over time. To identify the attributes of the urban environment that kit foxes used most, areas and habitats used disproportionately were compared to what was available in the urban landscape. The quantity and type of urban habitat needed to meet the ecological requirements of urban kit foxes (i.e., that used for denning, foraging, and traveling) was identified. To understand habitat use, kit fox home range size, core area size, spatial distribution of kit foxes in the urban landscape, habitat and den use, and movements were evaluated in relation to habitat type, time of night, and human activity. Assessment of habitat quality should be based on the survival, reproduction, and density of the species occupying the habitat (Van Horne 1983). Therefore, I also reported the demographic characteristics of captured urban kit foxes.
5 STUDY AREA
The study was conducted within the city limits of Bakersfield (Figure 1), at the southern end of the San Joaquin Valley, California. The average elevation of Bakersfield was 124 m (United States Geological Survey 1981) and in 1997, had a human population of 221,700 (State of California, Department of Finance 2002).
Bakersfield has an arid climate with an average annual precipitation of 14.5 cm (National Oceanic and Atmospheric Administration 1997) that occurs mainly between October and April.
Total precipitation during the study was 10.9 cm, 3.0 cm higher than normal (Meadows Field Weather Station; National Oceanic and Atmospheric Administration 1997, National Oceanic and Atmospheric Administration 1998). Summers are hot and dry, while winters are cool and moist.
During the study, average temperatures ranged from 7.9° C in December to 27.2° C in July and annual mean temperature was 19.6° C, which was -14.3° C lower than normal (Meadows Field Weather Station; National Oceanic and Atmospheric Administration 1997, National Oceanic and Atmospheric Administration 1998).
Vegetation in the study area varied by land use and was composed mostly of introduced and exotic species. Manicured open, commercial, and residential habitats were planted mainly with non-native grasses and shrubs (Table 1). Conversely, open, industrial, and some linear habitats, such as the Kern River Parkway, had a mix of introduced and endemic grasses, forbs, and shrubs. Sumps were primarily barren on the sides, often contained standing water, and had scattered native and non-native vegetation near the upper edges. In addition, sumps were distributed throughout the city, fenced, and closed to the public. Sumps had sloping sides and ranged from 0.01 to 0.03 km2 in area.
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C alifo rn ia
Kern C ounty
S t o c k d a l e H i g h w a y
In te rsta te 5 Fre ew a y
H ig h w a y 1 7 8
Fre ew a y
9 9
G o sf o rd Ro a d
F re e w a y 5 8
S T U D Y A R E A
B a k e rsfi e ld
Ke rn Riv er
3 0 3 6 k m
N
Figure 1. The study area in Bakersfield, Kern County, California for investigations of kit fox habitat use from May 1997 to January 1998. 6 7
Table 1. Habitat types and their descriptions used to typify the urban setting and kit fox habitat use in Bakersfield, California from May 1997 to January 1998.
Habitat type Description
Commercial Office buildings, hotels, medical facilities, and their associated parking areas.
Transition Areas in which residential, commercial, or industrial construction is in progress or has recently been completed.
Industrial Areas of industrial use not generally open to the public, such as manufacturing plants and shipping yards.
Linear Kern River Parkway, canals, roads, railroads, and highway and power line right-of-ways.
Manicured Open Parks, schools, and golf courses.
Open Vacant lots and fallow agricultural fields.
Residential Apartments and single-family housing developments.
Sumps Water catchment basins used to contain urban run-off and rainwater. 8 Kit fox predators, including bobcat, coyote, and domestic dog (Cypher et al. 2000), were observed at the study site. Bobcats and coyotes were only observed in the Kern River Parkway (personal observation). California ground squirrel (Spermophilus beecheyi), Botta's pocket gopher (Thomomys bottae), and desert cottontail (Sylvilagus audubonii) (all urban kit fox prey; Cypher and Warrick 1993), were observed at the study site. Domestic cats (Felis catus) and opossums (Didelphis virginiana), which utilize some of the same food resources as urban kit foxes and red foxes, were observed in the study area (Catling 1988, Golightly et al. 1994, Read and Bowen 2001) (Appendix A).
9 METHODS
Trapping
Between 3 May and 18 July 1997, wire-mesh live-traps (38 x 38 x 107 cm; Model 208, Tomahawk Live Trap Company, Tomahawk, WI) were set in sumps, parks, the Kern River Parkway, and privately-owned land in Bakersfield. Traps were covered with canvas tarps to protect captured animals from sun and inclement weather, and baited with canned mackerel.
Trapping frequency and trap placement was opportunistic. The trapping was limited to areas in southwest Bakersfield where kit foxes or their sign (i.e., tracks, scat, and dens) were observed.
Captured kit foxes were transferred from traps to heavy cloth bags for handling. Each animal was sexed, eartagged, weighed (+ 3%), measured (+ 1 mm; right ear and hind foot length), and released at the capture location. Uniquely-numbered metal eartags (Model 1005-4, National Band and Tag Company, Newport, KY) were affixed to the right ear for females and left ear for males. Kit foxes were aged based tooth eruption and wear (Harris 1978). Individuals with partially erupted teeth were classified as juvenile, and those with permanent teeth were classified as adults. Young of the year were classified as puppies until 14 July, and subadults from 15 July to 30 November, after which they were considered to be adults.
Locations
I attached 50-g collar-mounted radiotransmitters (Model 80, Telonics, Mesa, AZ) to captured adults. Radiocollars were equipped with mortality sensors that pulsed approximately twice the normal rate if there was no movement for four hours. Between 14 December 1997 and 15 January 1998, all but four study animals were captured and had their radiocollars removed. 10 Radiocollared kit foxes were located using portable receivers (Model TR-4, Telonics, Mesa, AZ), an omni-directional antenna affixed to a car, and a hand-held 2-element yagi antenna.
Kit foxes were located between 1630 and 0900 h because they were primarily active at night (Egoscue 1956, Golightly 1981, White et al. 2000). At the onset of the study in May 1997, nine study animals were randomly monitored to verify that they were not active during daylight hours.
With the exception of delineating the study area, only locations obtained between one hour before sunset and one hour after sunrise were used in analyses. Each kit fox was systematically located approximately once per night (hereafter referred to as daily locations) but rotated in the schedule each night. Although sampling effort for each study animal was equal at study end, every kit fox could not be found during each sampling period. When a kit fox could not be found, the area where it was previously located was searched for at least 30 min and then, if not located, it was searched for elsewhere in the study area concurrent with searches for other kit foxes.
The transmitted signal was followed until the kit fox was observed (sometimes with the aid of a flashlight) or tracked to a den, or the habitat patch from which the signal was emitted was encircled (White and Garrott 1990). This technique ensured that the location of and habitat used by each kit fox was classified without error (Samuel and Kenow 1992). I tried to stay at least 100 m from the study animals, so as to not alter their behavior (i.e., cause them to move from one habitat patch to another). To assess if this technique created a sampling bias by altering their behavior, each animal was classified as resting/walking, trotting, or running at the time of observation. When this technique was not feasible (e.g., the habitat patch was not accessible), kit fox locations were determined with triangulation, based on three bearings taken as close as possible (< 300 m) from the loudest signal source (Springer 1979). Immediately after a kit fox was located, the observer plotted the location on a 1996 City of Bakersfield street map (scale 1:29,000, Compass Maps, Inc., Modesto, CA) and recorded the number of people that were visible (i.e., not in buildings or large habitat patches) in the same habitat patch as the kit fox. 11 Mapped kit fox locations were digitized into a geographic information system (GIS; ArcView 3.2 with Spatial Analyst 2.0, ESRI, Redlands, CA), and displayed over the City of Bakersfield's 1997 GIS file titled “Land Status Land Condition Land-use,” as a background for guidance during digitizing. This GIS file was developed through the input of bearing and distance measurements (taken by land surveyors) to define parcel boundaries (i.e., the coordinate geometry method; Amos, R. 2005. Personal communication. City of Bakersfield, GIS Department, 1501 Truxtun Avenue, Bakersfield, CA 93301). Using methods in Romsos (1998), I characterized the urban landscape and described urban kit fox habitat use by collapsing similar urban landscapes into eight categories (Table 1).
To verify the accuracy of the habitat types and boundaries depicted in the GIS, maps generated from the GIS were compared to the actual location of habitat patches throughout the study area. When habitat was not correctly represented in the GIS, a global positioning system (GPS Pathfinder Pro XR, Trimble, Sunnyvale, CA) was used to obtain the geographic coordinates of the edges of each habitat patch. These coordinate data were differentially corrected using the GPS Pathfinder Office program to improve accuracy to within + 1 m, imported into the GIS, and used to digitize polygons representing the correct habitat patches.
The accuracy of the habitat types and boundaries depicted in the GIS was further verified by comparison to aerial photographs (Farm Services Agency, USDA, Bakersfield, CA) of the study area that were photographed in June 1997, at the beginning of the study, and in June 1998, after the study concluded. This comparison was done primarily to identify habitats that were classified as open in 1997 but were in transition or residential in 1998. In these instances, the date each house was built was determined by consulting Kern County public records data. Any habitat patch that was open in the June 1997 aerial photograph, on which a house was built prior to the end of the study, was classified as transition habitat. 12 Home Range
Home range estimates were obtained using the GIS to generate the 100% minimum convex polygon, which defined the bounds of the area used (Mohr 1947, Hooge and Eichenlaub 1997). Use of kernel-based estimators may be important to identify disjunct areas of activity in urban landscapes where habitat may be fragmented (Grinder and Krausman 2001). For comparison to other urban canid studies (Romsos 1998, Grinder and Krausman 2001), home range was also estimated using the 95% fixed kernel, a probabilistic model that identified the most probable area of utilization (Worton 1989, Seaman and Powell 1996). To represent the core area for each study animal, I used the 50% fixed kernel, which identified the areas that encompassed 50% of the animal’s locations (Calhoun and Casby 1958, Jennrich and Turner 1969, Anderson 1982). Large bodies of water (e.g., Lake Truxtun) were removed from the estimates of home range area and available habitat (White and Garrott 1990).
Probabilistic home range techniques (e.g., fixed kernel) are sensitive to serial autocorrelation (Anderson 1982, Hooge et al. 1999). The minimum convex polygon home range estimator assumes that location data are not time correlated (Anderson 1982, White and Garrott 1990), but are robust to violation of this assumption. Only statistically independent data (i.e., the data point provided no indication of the category for the next data point) were used to estimate home range and core area size. Time to statistical independence between successive locations was based on the time it took each kit fox to cross its home range (White and Garrott 1990, Lucherini et al. 1995, Harrison 1997). To derive this estimate, I divided the mean speed for each of 10 kit foxes that were located approximately every 15 - 30 min during two to six 3 - 5 h movement sessions (hereafter referred to as sequential locations), by the longest axis of their 100% minimum convex polygon home range (Jenness 2003).
Area-observation curves were used to determine the minimum number of kit fox locations necessary for home range estimation (Odum and Kuenzler 1955). To do so, I iteratively 13 estimated the 100% minimum convex polygon home range for each kit fox, beginning with the first 10 locations and adding one consecutive location at a time. The area of each 100% minimum convex polygon was plotted against the number of locations from which it was estimated. The point on the curve at which each 10 additional locations did not increase the home range estimate by 10% was the minimum number of locations needed to estimate home range.
Because home range size may vary with sex (Burt 1943), a 2-sample t-test was used to determine if home range size differed between males and females (Hintze 1999). For comparison to rural kit fox studies in Arizona (Golightly 1981) and California (Zoellick et al. 1987, White and Ralls 1993, Koopman 1995), the 100% minimum convex polygon home range estimate was used for this analysis. All data were checked for normality and equal variance, and data that could not be normalized by transformation were analyzed with non-parametric tests. Significance level (α) was 0.05.
Home range size may also vary by season (Burt 1943). To assess if the area of the urban environment needed to meet kit foxes’ ecological requirements fluctuated throughout the year, I determined if home range size varied with biological season for urban kit foxes, as it did for rural kit foxes (Zoellick et al. 1987). Because kernel-based estimates from small sample sizes (e.g., from subsetting the data by season) tend to overestimate home range sizes (Seaman and Powell 1996), seasonal home ranges were estimated using 100% minimum convex polygons, which is more robust than other techniques when sample size is small (Harris et al. 1990). Data were normalized with a square-root transformation and analyzed with a 2-way analysis of variance (Winer et al. 1991, Hintze 1999) to compare mean home range size for male and female kit foxes during three biological seasons: dispersal (1 June to 30 September); pair formation (1 October to 30 November); and breeding (1 December to 15 February; Zoellick et al. 1987, Reese et al. 1992, Koopman et al. 1998). A Fisher's least significant difference multiple comparison test (Hintze 1999) was used to determine what factors (i.e., season and sex) in the analysis of variance were 14 significantly different. Study animals were located too seldom to estimate home range during the pup rearing season (16 February to 31 May).
The presence of food-rich habitat patches within territories may allow additional group members. Macdonald (1983) predicted that the home range of a mated pair of red foxes may overlap and support other foxes if there were sufficient resources. However, if food is evenlydispersed among habitat patches, a larger home range would be required and the tolerance of additional adults in the territory of a pair would be predicted to be less. I predicted that if kit foxes were concentrated around limited resources, home ranges and core areas of adjacent kit foxes would have a high percentage of overlap. The GIS was used to identify the percentage of overlap between a) adjacent 100% minimum convex polygon home ranges and b) adjacent core area polygons between kit fox pairs comprised of a) mated pairs or family groups, b) adjacent females, c) adjacent males, and d) adjacent but unpaired males and females.
It was assumed that habitats that were used disproportionately more than available contained key resources. To assess if habitats with key resources (i.e., denning and foraging sites) were equally-dispersed or conversely, concentrated, the mean percentage of area of each 100% minimum convex polygon that the core area represented was determined. If areas of habitat use were concentrated, then the 50% fixed kernel should encompass less than 50% of the area used by each kit fox. If areas of use were uniform rather than concentrated, the 50% fixed kernel would comprise half of the area within the 100% minimum convex polygon. To assess if use of key resources differed among the sexes, the median number of core areas for females and males was compared with a Mann-Whitney U-test, and the mean core area size for males and females was compared with a 2-sample t-test.
15 Habitat Use
For those kit fox locations determined from triangulation, the likelihood for habitat misclassification increased with animal proximity to habitat edge and decreased as habitat-patch size increased (Samuel and Kenow 1992). To assess the probability of habitat misclassification, the GIS was used to determine the distance between each triangulated location and the nearest habitat-patch edge (Jenness 2004a). I reasoned that triangulated kit fox locations less than 100 m from the nearest habitat-patch edge may have had misclassification of habitat type. The 100 m value was selected because urban coyote studies that used similar methods to study habitat use, had average telemetry errors of 46 m (Grinder and Krausman 2001) and 102 m (Romsos 1998).
Use of habitat is considered selective if it is exploited disproportional to its availability (Johnson 1980). Habitat selection can occur at a variety of scales (Wiens 1973, Orians and Wittenberger 1991, Litvaitis et al. 1996, Apps et al. 2001). I analyzed habitat use within the individual kit fox home range and core area and for the kit fox population in the study area. To determine if kit foxes used urban habitat types (Table 1) with a frequency proportional to their availability, the independent locations that fell within a) the study area and b) each home range were selected. To delineate the study area, a 100% minimum convex polygon was generated using all daily, sequential, and trapping locations for all study animals (Litvaitis et al. 1996, Romsos 1998, Kamler et al. 2003). For comparison to other urban canid habitat use studies (Romsos 1998, Grinder and Krausman 2001), the 95% fixed kernel was used to represent the home range of each kit fox. The area of each habitat type in the study area and each home range was summed, and use of habitat types in each was compared with a Friedman's test (Alldredge and Ratti 1986, Hintze 1999; individual kit fox was the blocking factor, habitat type was the treatment factor, and the ranked numerical difference between the proportion of habitat used and the proportion of habitat available was the response variable). To determine which habitat types 16 were used significantly more than their availability, a Fisher's least significant difference procedure (Alldredge and Ratti 1986, Hintze 1999) was used.
How kit foxes used urban habitats was determined at two scales: within each home range in proportion to what was available in the study area; and within each core area in proportion to what was available in the corresponding home range. For each habitat type, I compared the proportion a) within each home range and the study area and b) within each core area and corresponding home range. Prior to analysis, the proportion data were arcsine transformed (Winer et al. 1991) and analyzed with a matched-pair t-test, or a Wilcoxon signed-rank test if data could not be normalized (Hintze 1999).
Fox habitat use may also be influenced by human presence (Lucherini et al. 1995); therefore, I treated human activity as an attribute of habitat. After each kit fox was located, an index of human activity was gained by counting the number of vehicles and pedestrians that passed by an imaginary line that was perpendicular to the nearest road in a 15 second period. The number of people that were visible (i.e., not in buildings or large habitat patches) in the same habitat patch as the kit fox was also recorded. To determine if human activity (i.e., the number of passing vehicles, passing pedestrians, and people in the same habitat patch as the kit fox) varied among the habitat types, a Kruskal-Wallis 1-way analysis of variance was used, followed by a Kruskal-Wallis multiple comparison test to determine what factors in the analysis of variance were significantly different.
Relative to some rural landscapes that have uniformly-distributed resources (Koopman 1995, Kamler et al. 2004), urban landscapes are highly fragmented, have isolated, clumped resources (Grinder and Krausman 2001), and consist of a patchy mosaic of habitats (Morrell 1975). Some urban habitats may be more suitable for denning and consequently, are used more than their availability in the study area. If certain habitats were selected for denning, the spatial 17 arrangement of home ranges would be influenced by the availability of the selected habitat types (Golightly 1981, Hardenbrook 1987).
The geographic coordinates of each den (i.e., refugia receiving repeated use by the study animals) were determined using a GPS and imported into the GIS. Dens were categorized as subterranean, culvert (or pipe), or man-made structure. To understand if den sites influenced habitat use, a 1-proportion z-test (Winer et al. 1991, Hintze 1999) was used to determine if habitats were used for denning in proportion to their availability in the study area.
Using the GIS, I generated random points (with a uniform distribution) equivalent to the number of dens in the study area (Hooge and Eichenlaub 1997). To assess if road proximity influenced den locations, the GIS was used to determine the distance of each den and random point to the centerline of the nearest road (Jenness 2004a). A Mann-Whitney U-test was used to determine if den sites and random points differed with regard to distance to the nearest road. A Wilcoxon signed-rank test was used to determine if the median size of habitat patches within which dens were located differed from the median habitat-patch size in the study area.
Movements
Canid movement behavior may indicate use of habitat for resting, foraging, and traveling (Ozoga and Harger 1966, Laundré and Keller 1981, Romsos 1998). Between 8 September 1997 and 7 January 1998, a randomly-selected subsample (five females and five males) of radiocollared kit foxes was examined for movements and travel paths through adjacent habitat patches in order to identify which behaviors were associated with each habitat type. Based on behavior-specific movement types for canids in Ozoga and Harger (1966) and Laundré and Keller (1981), I categorized kit fox movement as resting/walking (i.e., inactivity at low speeds between 0 - 0.8 km/h), trotting (i.e., potentially searching for food at intermediate speeds between 0.8 - 1.8 km/h), and running (i.e., traveling from one point to another at high speeds greater than 1.8 18 km/h). Movements were assessed during three nocturnal sampling periods, approximately 1830 - 2230 h, 2230 - 0330 h, and 0330 - 0730 h. Each kit fox was followed two to six times during each of the three sampling periods.
While following kit foxes, sequential locations were determined approximately every 15 - 30 min during the sampling period. Movement sessions with more than one hour between any two successive locations were deemed incomplete and repeated on another day. The locations identified during each movement session were plotted on a 1996 City of Bakersfield street map (scale 1:29,000, Compass Maps, Inc., Modesto, CA). Time, habitat type, kit fox activity (e.g., resting/walking, trotting, running), and number of passing vehicles, passing pedestrians, and people in the same habitat patch as the kit fox were recorded.
GIS was used to digitize kit fox locations and generate a line from the set of sequential location points for each movement session. Each line was then intersected with the habitat types through which it passed (Jenness 2004b). Kit fox speed (the distance between two sequential locations divided by the time elapsed) was regressed against the number of passing vehicles, passing pedestrians, and people in the same habitat patch to examine the influence of humans on kit fox habitat use. A multivariate analysis of variance was used to determine if sex and movement session time influenced minimum travel speed, maximum speed, mean speed (using all speed estimates except when the kit fox was at a den or resting), and total distance moved per movement session (Woodruff and Keller 1982). Because movement session length varied, total distance moved was standardized by multiplying the distance measure by the ratio of 1) the length of time elapsed during the shortest movement session to 2) the length of time elapsed during the movement session with which the distance measure was associated.
To determine if total distance moved per movement session varied by habitat type, I used a Kruskal-Wallis 1-way analysis of variance (Zoellick et al. 1989). A Kruskal-Wallis 1-way analysis of variance was used to determine if overall median speed was influenced by habitat 19 type. Kruskal-Wallis multiple comparison tests were used to determine what factors in these analysis of variance tests were significantly different.
A loglinear model was used to examine correlations between type of movement, frequency of relocations per habitat type, and time of movement session. To identify the habitat type and movement session (i.e., evening, middle of the night, and early morning) within which kit foxes rested/walked, trotted, and ran, standardized residuals were used to identify the greatest deviations from expected for kit fox movements.
Demographics
Reproduction and mortality in radiocollared kit foxes were measured to determine if demographic parameters of urban kit fox populations were similar to those for rural kit fox populations, and assess habitat quality in the urban landscape (Van Horne 1983). Kit foxes with a radiocollar in a mortality mode were immediately located and necropsied to assess cause of death.
This information was used to determine sources and rates of kit fox mortality, which were compared to data for rural kit fox populations. I determined the number of radio-days since each kit fox was radiocollared and the survival rate for that time interval, described by Heisey and Fuller (1985) as the interval survival rate. Paired tooth puncture wounds associated with subcutaneous hematomas on the carcass were indicative of a predator kill, and if the carcass exhibited massive trauma and was located near a road, the cause of death was determined to be vehicular impact (Spiegel and Disney 1996).
The number of pups incidentally trapped or observed with radiocollared adult kit foxes and their mates were identified. Additionally, as part of a concurrent study (Storlie 1998) of juvenile kit fox dispersal and mortality, trapping effort was conducted in areas where pups were captured or observed. Capture data from both studies were used to estimate litter size for kit 20 foxes in the study area. The annual reproductive success rate was based on the percentage of radiocollared females that produced pups.
21 RESULTS
Trapping
Between 1 May 1997 and 15 January 1998, 107 (30 adult males, 31 adult females, and 46 juveniles) kit foxes were captured in all habitat types in which traps were placed (Appendix A).
Mean adult kit fox weight was 2.47 + 0.05 (x¯ + 1 SE) kg for males and 2.16 + 0.03 kg for females.
Locations
Radiocollars were attached to 28 adults (13 males, 15 females). Each radiocollared kit fox was located 5.1 + 0.3 days each week. Of the 35 kit foxes located between 0900 and 1600 h, 34 were stationary (e.g., resting) or in a den. In 252 study days, a total of 1,882 sequential locations (during 111 movement sessions) and 4,824 daily locations were determined for the 28 study animals. Of these locations, 4,249 were independent, of which 2,898 (68%) were considered to be exact and the habitat types in which they occurred were correctly classified, based on being tracked to a den (n = 811) or directly observed (n = 2,087). Directly observed kit foxes were classified as stationary for 52% of the observations (Figure 2). Of the 1,351 triangulated locations, 66 were > 100 m from the nearest habitat-patch edge. The remaining locations were on average 31.3 + 0.6 m from the nearest habitat-patch edge.
Home Range
Based on the area-observation curves (Odum and Kuenzler 1955; Appendix D), the average number of locations needed to estimate a 100% minimum convex polygon home range was 27 + 1.7. All sequentially-located kit foxes could cross the longest axis of their 100% 22 0
10 20
30 40
50 60
Resting/Walking Trotting Running Other
Behavior Type
Observations (%)
Figure 2. Behavior exhibited by directly observed kit foxes at independent daily locations (n = 2,087) in Bakersfield, California from May 1997 to January 1998. 23 minimum convex polygon home range in less than four hours (range = 1.23 - 3.89 h; Appendix B). Therefore, four hours was used as the time to independence between kit fox locations.
The 100% minimum convex polygon home range size for all study animals combined was 1.72 + 0.19 km2 and was larger for males than females (Table 2). Average 95% fixed kernel home range size for all study animals combined (excluding one outlier) was 1.2 + 0.19 km2 (range = 0.04 – 2.78). Excluding one outlier, core areas comprised 9.1 + 1.2% (range = 1.9 –
19.6) of the 100% minimum convex polygon home range. Kit foxes had an average of 2.15 +
0.23 distinct core areas, and females had more than males. Mean 100% minimum convex polygon home range size was significantly larger during the dispersal season than during the pair formation and breeding seasons (F = 7.79, df = 2, p < 0.001) and for males than females during the breeding season (F = 4.47, df = 1, p = 0.04), and there was no interaction between season and sex (F = 2.38, df = 2, p = 0.1) (Table 3). The percentage of home range and core area overlap between kit foxes was highest for family group members (Figure 3).
Habitat Use
The study area was 76 km2, and had 3,908 habitat patches that averaged 0.01 + 0.001 km2 (range was < 0.01 - 2.03, except for a 17.88 km2 patch that comprised all interconnecting linear features that was excluded from this calculation). Kit foxes used urban habitats disproportionate to their availability in the study area (Q = 103.5, df = 7, p < 0.001) and within home ranges (Q =
91.36, df = 7, p < 0.001; Figure 4). Open and sump habitats were used more than their availability in both the study area and in home ranges (Table 4). There was less area of residential habitat but more area of open and sump habitats in home ranges than in the study area.
Area of transition, commercial, manicured open, linear, and residential habitats were less, but area of sump habitat was greater, in core areas than in home ranges (Table 5).
Table 2. Home range (100% minimum convex polygon) and core area (50% fixed kernel) size for radiocollared kit foxes in Bakersfield, California from May 1997 to January 1998.
All Males Females Males vs. Females
Measurement x¯ SE Range x¯ SE Range x¯ SE Range Statistic df p Home range size (km2) 1.72 0.19 0.31 - 4.49 2.12 0.31 0.31 - 4.49 1.36 0.21 0.36 - 2.71 t = -2.08 25 0.02 Core area size (km2) 0.16a 0.03 0.01 - 0.5 0.18 0.05 0.01 - 0.5 0.15 0.04 0.02 - 0.43 t = -0.57 24 0.57 Core areas per kit fox 2.15 0.23 1 – 6 1.85 0.37 1 - 6 2.43 0.27 1 - 4 z = -1.98 25 0.02 a Excluding one outlier (the male with two distinct home ranges). 24 25
Table 3. Seasonal home range (100% minimum convex polygon) size for radiocollared kit foxes in Bakersfield, California from May 1997 to January 1998.
Home range (km2)
All Males Females
Season x¯ SE x¯ SE x¯ SE
Dispersal 1.24 0.11 1.32 0.16 1.17 0.15
Pair formation 0.77 0.11 0.79 0.16 0.74 0.16
Breeding 0.66 0.12 0.95 0.16 0.38 0.16
26 0
20 40
60 80
Family Group Male-Female Male-Male Female-Female
Pair Type
Overlap (%)
Home Range
Core Area
Figure 3. Percentage of home range overlap and core area overlap for pairs of radiocollared kit foxes in Bakersfield, California from May 1997 to January 1998. Vertical bars represent + 1 SE.
0 5
10 15
20 25
30 35
40 Residential Linear Commercial Open Manicured
Open
Industrial Sump Transition
Habitat Type
Area (%)
Study Area
Home Range
Core Area
a
c
b
b
a
a
b
a
b
c
a b
a
b
a
b
Figure 4. Mean percentage of each habitat type in the study area, which bounded the available habitat, and radiocollared kit fox home ranges (n = 27) and core areas (n = 58) in Bakersfield, California from May 1997 to January 1998. Different letters above the bars indicate a significant difference in habitat use versus availability.
27 Table 4. Ranked radiocollared kit fox habitat use based on habitat availability at the study area and home range area scale, in Bakersfield, California between May 1997 to January 1998. Habitat types used similarly (p > 0.05) are grouped by column.
Study Area Home Range
Habitat Types
Statistically Similar in Use
Mean
Rank
Habitat Types
Statistically Similar in Use
Mean
Rank
Rank
of
Use
Open 2.1 Sump 2.3 Most
Sump 2.6 Open 2.5
Transition 4.0 Transition 3.5
Industrial 4.0 Industrial 3.9
Manicured Open 4.4 Manicured Open 5.3
Commercial 5.4 Commercial Commercial 5.8
Linear 5.6 Linear Linear 6.2
Residential 7.8 Residential 6.6 Least28
29 Table 5. Mean difference between the mean proportion of habitat available in the study area and kit fox home ranges (e.g., there was 16.7% less open habitat in the study area than within home ranges), and kit fox home ranges and core areas in Bakersfield, California between May 1997 to January 1998.
Study Area and Home Range Home Range and Core Area
Habitat Type Percent
Difference Statistic p
a Percent
Difference Statistic p
b
Commercial -1.3 t = 0.89 0.38 2.8 t = -2.79 <0.01
Industrial -1.2 z = 1.43 0.15 -2.2 z = 0.05 0.47
Linear 2.5 t = 1.47 0.15 4.3 z = -2.25 0.01
Manicured Open -6.2 t = -0.59 0.56 3.7 z = -1.77 0.02
Open -16.7 t = -3.83 <0.01 -7.5 t = 1.46 0.16
Residential 25.8 z = 4.52 <0.01 6.4 t = -5.5 <0.01
Sump -1.9 z = -2.88 <0.01 -7.6 z = 2.19 0.01
Transition -1.0 t = -0.66 0.51 0.2 t = -2.30 0.01
a,b Because the analysis used multiple t-tests, the probability of at least one false rejection of the null hypothesis was 1 – 0.958 = 0.34 (Winer et al. 1991). 30 Number of people in the same habitat patch as the kit fox varied between habitat types and was greatest in manicured open habitat (H = 285.7, df = 7, p < 0.001; Figure 5). Industrial and linear habitats had a higher incidence of passing vehicles than all other habitats (H = 355.1, df = 7, p < 0.001; Figure 5). A greater number of pedestrians were observed along roads near sumps than all other habitats (H = 136.8, df = 7, p < 0.001; Figure 5).
The study animals used 190 dens, comprised of 159 subterranean dens, 17 culvert or pipe dens, and 14 man-made structure dens (e.g., metal storage containers, modular office buildings, junkyard debris, a shed, and a garbage dumpster), most of which were located in open, sump, and linear habitats (Figure 6). Sump (z = 45.74, df = 1, p < 0.001) and open (z = 11.47, df = 1, p <
0.001) habitats were used for denning more than their availability in the study area (Figure 7).
Residential (z = -10.5, df = 1, p < 0.001) and commercial (z = -3.67, df = 1, p < 0.001) habitats were used for denning less than their availability in the study area. Linear (z = -1.24, df = 1, p =
0.19), manicured open (z = -0.53, df = 1, p = 0.59), industrial (z = -0.3, df = 1, p = 0.76), and transition (z = -0.45, df = 1, p = 1.0) habitats were used for denning in proportion to their availability in the study area.
Dens were located farther from roads (0.10 + 0.01 km, range = 0.01 - 0.5) than randomlygenerated points (0.06 + 0.01 km, range = 0.0001 - 0.55; z = 8.17, df = 378, p < 0.001). The median size of habitat patches within which dens were located (0.03 km2) was significantly larger than the median habitat-patch size in the study area (0.004 km2; z = 10.56, df = 1, p <
0.001).
Movements
Movement sessions (n = 100) lasted from 184 to 315 min long. Kit foxes moved at an average rate of 1.33 + 0.02 km/h. Minimum speed during each movement session was influenced Vehicles Passing on Nearest Road
0 0.5
1 1.5
2 2.5
1 2 3 4 5 6 7 8 Vehicles/15 s
Pedestrians Passing Along Nearest Road
0 0.1
0.2 0.3
0.4 1 2 3 4 5 6 7 8 Pedestrians/15 s
People in Habitat Patch
0 0.2
0.4 0.6
0.8 Linear Industrial Residential Sump Commercial Open Manicured Open
Transition
Habitat Type
People/15 s
Figure 5. Mean number of passing vehicles, passing pedestrians, and people in the same habitat patch as radiocollared kit foxes at all daily locations (n = 4,824) in Bakersfield, California from May 1997 to January 1998. Vertical bars represent + 1 SE. 31 0
10 20
30 40
50 60
70 Open Sump Linear Manicured
Open
Industrial Commercial Residential Transition
Habitat Type Number of Dens
Man-made Structures
Culvert/Pipe
Subterranean
Figure 6. Number of dens used by radiocollared kit foxes in each habitat type in Bakersfield, California from May 1997 to January 1998. 32 0 5
10 15
20 25
30 35
40 Residential Linear Commercial Open Manicured
Open
Industrial Sump Transition
Habitat Type
Habitat (%)
Study Area Available
Used for Denning
Figure 7. Percentage of available habitat in the study area compared to percentage of habitat used by radiocollared kit foxes for denning in Bakersfield, California from May 1997 to January 1998.
33 34
by the interaction of sex and time of night (Figure 8, Table 6). The regressions of kit fox speed and the number of passing vehicles (r2 = 0.0077), passing pedestrians (r2 = 0.0016), and people in the same habitat patch as the kit fox (r2 = 0.0002), respectively, indicated that these variables (all of which could not be normalized through transformation) were not related to kit fox speed. The distance traveled during each movement session was longer in manicured open and open habitats than all other habitats (H = 125, df = 7, p < 0.001; Figure 9). Overall speed was faster in residential habitat than all other habitats (H = 111.6, df = 7, p < 0.001; Figure 10).
There was a significant interaction between kit fox movements, movement session time, and habitat type (c
2 = 61.48, df = 28, p < 0.001). Kit fox resting/walking movements deviated most from expected from 1830 – 2230 h, during which linear habitat was used more than expected and from 2230 – 0330 h, during which residential habitat was used less than expected (Table 7). Kit fox trotting movements deviated most from expected from 2230 – 0330 h during which open habitat was used more than expected, and from 2230 – 0730 h during which sump habitat was used less than expected. The greatest deviations from expected kit fox running movements were from 2230 – 0330 h during which open habitat was used more than expected, and from 0330 – 0730 h during which industrial habitat was used less than expected.
Between 27 September and 4 October 1997, a male kit fox moved > 5.9 km from his previouslyestablished home range to another part of the study area, where he remained until the end of the study. Kit foxes were observed crossing roads (up to four lanes), but also used culverts to move under roads. One study animal was observed to use a 0.46-m in diameter culvert to cross under a State Route 99 offramp and a 4.26 m wide by 3.66 m high vehicle access road to cross under State Route 99. Other kit foxes were observed to cross under the State Route 99 bridge over the Kern River and use a foot bridge to cross a canal.
35 0
0.05 0.1
0.15 0.2
0.25 0.3
0.35 0.4
1830 - 2230 2230 - 0330 0330 - 0730
Time Period
Minimum Speed of Travel (km/hr)
Males
Females
Figure 8. Minimum speed per movement session for male and female radiocollared kit foxes in Bakersfield, California from September 1997 to January 1998.
Table 6. Influence of sex, movement session time, and their interaction on minimum, maximum, and mean speed and total adjusted distance moved for 10 radiocollared kit foxes in Bakersfield, California from May 1997 to January 1998.
Males Females Males vs. Females
Movement Session
Time Interaction
Measurement x¯ SE Range x¯ SE Range F-Ratio df p F-Ratio df p F-Ratio df p Minimum
Speed (km/hr2) 0.26 0.03 0.02 - 0.75 0.27 0.03 <0.01 - 1.16 0.05 1 0.82 0.58 2 0.56 3.17 2 0.047 Maximum
Speed (km/hr2) 2.19 0.13 0.26 - 4.65 2.17 0.22 0.32 - 9.06 0.1 1 0.75 2.5 2 0.09 0.21 2 0.81 Mean Speed
(km/hr2) 1.39 0.03 0.02 - 4.65 1.25 0.03 <0.01 - 9.06 1.32 1 0.25 1.08 2 0.34 0.15 2 0.86 Total Adjusted
Distance
Moved (km) 1.76 0.11 0.12 - 3.34 1.62 0.15 0.13 - 4.77 0.88 2 0.35 1.81 2 0.17 1.16 2 0.32 36 0
0.2 0.4
0.6 0.8
1 1.2
Manicured
Open
Open Residential Linear Industrial Commercial Transition Sump Habitat Type
Mean Distance Traveled (km)
Figure 9. Mean distance radiocollared kit foxes traveled in each habitat type in Bakersfield, California from September 1997 to January 1998.
Vertical bars represent + 1 SE.
37 0
0.2 0.4
0.6 0.8
1 1.2
1.4 1.6
1.8 2
Residential Manicured
Open
Commercial Sump Industrial Open Linear Transition
Habitat Type
Mean Speed (km/hr)
Figure 10. Mean speed radiocollared kit foxes traveled in each habitat type in Bakersfield, California from September 1997 to January 1998.
Vertical bars represent + 1 SE.
38 Table 7. Movement session time, type of movement, and habitat associations for radiocollared kit foxes in Bakersfield, California from September 1997 to January 1998.
Movement Type Movement Session Time (h) Habitat Type Observed Frequencya Standardized Residualb Resting/Walking 1830 - 2230 Sump 11 -5.19
Transition 18 -4.16
Residential 19 -4.02
Commercial 30 -2.40
Industrial 58 1.71
Manicured Open 107 8.91
Open 185 20.37
Linear 205 23.30
2230 - 0330 Residential 6 -5.93
Transition 12 -5.05
Sump 13 -4.90
Commercial 28 -2.69
Manicured Open 76 4.36
Industrial 78 4.65
Linear 89 6.27
Open 194 21.69
0330 - 0730 Commercial 15 -4.60
Residential 15 -4.60
Transition 26 -2.99
Sump 35 -1.67
Industrial 38 -1.23
Manicured Open 57 1.56
Open 164 17.28
Linear 174 18.75
39 Table 7. Movement session time, type of movement, and habitat associations for radiocollared kit foxes in Bakersfield, California from September 1997 to January 1998 (continued).
Movement Type Movement Session Time (h) Habitat Type Observed Frequencya Standardized Residualb Trotting 1830 - 2230 Sump 12 -5.05
Transition 12 -5.05
Residential 25 -3.14
Industrial 29 -2.55
Commercial 33 -1.96
Manicured Open 45 -0.20
Open 96 7.29
Linear 105 8.62
2230 - 0330 Sump 6 -5.93
Transition 13 -4.90
Residential 14 -4.75
Industrial 25 -3.14
Manicured Open 30 -2.40
Commercial 41 -0.79
Linear 94 7.00
Open 115 10.08
0330 - 0730 Sump 6 -5.93
Transition 20 -3.87
Industrial 25 -3.14
Commercial 28 -2.69
Manicured Open 29 -2.55
Residential 46 -0.05
Linear 72 3.77
Open 97 7.44
40 Table 7. Movement session time, type of movement, and habitat associations for radiocollared kit foxes in Bakersfield, California from September 1997 to January 1998 (continued).
Movement Type Movement Session Time (h) Habitat Type Observed Frequencya Standardized Residualb Running 1830 - 2230 Sump 6 -5.93
Industrial 14 -4.75
Transition 16 -4.46
Commercial 19 -4.02
Linear 50 0.54
Manicured Open 54 1.12
Residential 61 2.15
Open 64 2.59
2230 - 0330 Transition 6 -5.93
Sump 7 -5.78
Industrial 25 -3.14
Residential 27 -2.84
Commercial 35 -1.67
Manicured Open 38 -1.23
Linear 53 0.98
Open 66 2.89
0330 - 0730 Industrial 2 -6.51
Sump 4 -6.22
Transition 6 -5.93
Commercial 8 -5.63
Linear 21 -3.72
Manicured Open 24 -3.28
Open 30 -2.40
Residential 30 -2.40
a Number of times a kit fox movement path intersected each habitat type, separated by movement type and movement session time. b Negative values indicate that a habitat was used less than expected and positive values indicate that a habitat was used more than expected.
If the value is > + 2.00 (2 standard deviations), it is significant. 41 42
Demographics
During 6,036 days of active radiotransmitters, two of the 28 radiocollared kit foxes died and the interval survival rate was 0.92. One female was hit by a vehicle and another female was likely killed by a coyote or domestic dog, based on 30 to 35-mm paired puncture wounds on the torso of the intact, unburied carcass (Spiegel and Disney 1996). It was unknown if another female that could not be located after 3 September 1997, died, dispersed, or had a malfunctioning radiocollar.
Pups were detected with 15 family groups, comprised of 22 radiocollared adult kit foxes.
Eleven of the 15 radiocollared females reproduced during one breeding season. Four of these 11 females had radiocollared mates. An additional four radiocollared males had uncollared mates that also reproduced in the same breeding season. Kit fox litters averaged 2.8 + 0.45 (range = 1 – 7) pups. The litter of 7 pups was observed denning with two radiocollared females, of which one exhibited reproductive condition and one did not.
43 DISCUSSION
Demographics
The urban kit foxes had lower mortality and similar reproduction and body weight compared to rural populations (Morrell 1972). Conversely, Cypher and Frost (1999) found that kit foxes in Bakersfield (i.e., females in winter and juveniles) were heavier than their counterparts in a nearby rural population. Urban kit foxes’ normal weights may be attributed to good nutrition. The constant source of water from sumps, canals, and lawn sprinklers in Bakersfield (Murphy 1992) may provide a more stable prey population. Like urban red foxes in Orange County, California (Lewis et al. 1993) and Toronto, Canada (Rosatte et al. 1991), urban kit foxes were supplementally fed (i.e., anthropogenic sources of food, including bread and burritos) by people and observed opportunistically foraging on both anthropogenic and natural food items (personal observation).
Urban kit foxes in Bakersfield may have lower mortality rates than rural foxes (Table 8).
Of 22 adult kit foxes from a nearby rural population that were radiocollared prior to or during late November and December 1995 through September 1996, 15 (68.2%) died and two were lost (Enterprise Advisory Services, Inc. 1997). Of 35 adult kit fox mortalities (including the two from this study) in the Bakersfield area from 1997 to 2003, 23% were due to vehicular impact (Bjurlin and Cypher 2003). The interval survival rate for urban kit foxes (0.92) was much greater than that for rural kit foxes (0.58; Ralls and White 1995; 0.44; Cypher et al. 2000).
Coyote predation may be more likely if a fox is far from its den (Kitchen et al. 1999) or in the peripheral areas of its home range (Sovada et al. 1998, Olson and Lindzey 2002). The majority of swift fox (Vulpes velox) deaths were due to coyotes and occurred outside the 85% Table 8. Rural kit fox and swift fox cause-specific mortality rates reported within their geographic range for comparison to that for urban kit foxes in Bakersfield, California from May 1997 to January 1998.
Cause-Specific Mortality Rate (%)
Reference Species Location Predation Vehicular Impact
Cypher et al. 2000 Kit Fox Kern County, CA 48.5 5.0
Ralls and White 1995 Kit Fox Carrizo Plain, CA 78.0 4.0 Hardenbrook 1987 Kit Fox Churchill County, NV 60.0 10.0 Spiegel and Disney 1996 Kit Fox Kern County, CA 66.7 1.7 Standley et al. 1992 Kit Fox Monterey and San Luis Obispo Counties, CA 75.0 6.3 Kamler et al. 2003 Swift Fox Dallam County, TX 33.0 42.0 Matlack et al. 2000 Swift Fox Sherman and Wallace Counties, KS 45.0 36.0 44 45
(Kitchen et al. 1999) or 95% (Sovada et al. 1998, Olson and Lindzey 2002) isopleth of the fox’s home range and more than 1 km from the den that the fox most recently occupied. Likewise, the urban kit fox that died as a result of coyote or dog predation was located outside the 85% isopleth of her range.
Production of young exceeded the number of kit foxes that died, which may have indicated that the urban kit fox population was demographically healthy during the period of study and habitat was of sufficient quality to support a source population (Van Horne 1983, Pulliam 1988, Noss et al. 1997). Seventy-three percent of radiocollared females produced pups, more than that observed for rural kit foxes in southwestern Kern County (64%; Spiegel and Tom 1996; 61%; Cypher et al. 2000). The mean number of pups per litter was within the range of that for rural populations: 2 (White and Ralls 1993) to 4 (Morrell 1971, Cypher et al. 2000).
Kit fox reproduction has been positively correlated with prey availability (White and Ralls 1993). Raccoons and skunks in Toronto, Canada weighed more and had higher reproductive success than their rural counterparts, which Rosatte et al. (1991) attributed to abundant and varied natural and human-derived food sources in the urban setting. The results of a supplemental feeding study indicated that kit fox survival and reproductive success were influenced by food availability (EG&G Energy Measurements 1993). Supplemental feeding by humans and the availability of refuse may contribute to the demographic health of urban kit foxes.
Locations
During daylight hours, urban kit foxes were found to be resting or in dens on all but one occasion. Like rural kit foxes in California (Morrell 1971, Morrell 1972, White et al. 2000), Utah (Egoscue 1956, O’Neal et al. 1987, Arjo et al. 2003), and Arizona (Golightly 1981, Golightly and Ohmart 1983) and urban red foxes in Orange County, California (Sallee 1998), urban kit foxes 46 were almost entirely nocturnal. Similarly, urban coyotes in Orange County, California (Romsos 1998), Seattle, Washington (Quinn 1995), and Tucson, Arizona (Grinder and Krausman 2001) were less active during daylight than at night. Urban kit foxes were primarily nocturnal and limited their daytime activity to the immediate vicinity of the den, similar to rural kit foxes (Morrell 1971, Morrell 1972), rural swift foxes (Kilgore 1969, Kitchen et al. 1999, Kamler et al. 2004), and urban red foxes (Voight and Macdonald 1984). Urban canids may benefit from being active only at night when interactions with humans are less likely.
Home range
Knowledge of home range size and spatial distribution can be used to manage urban habitat for the benefit of kit foxes. Home range estimates were much smaller than those for rural kit foxes (Table 9), but consistent with observations that foxes (Voight and Macdonald 1984, Murphy 1992) and raccoons and skunks in urban areas have smaller ranges than their rural counterparts (Rosatte et al. 1991).
Macdonald (1983) and Doncaster et al. (1990) attributed the tendency for red fox home ranges to be smaller in cities (e.g., Oxford) than in rural areas, to the spatial and temporal patchiness of food dispersion. Red foxes in Orange County, California had smaller home ranges where they were supplementally fed (Sallee 1998). Ables (1969) noted that the smaller home ranges for red foxes in south-central Wisconsin may have been due to habitat richness (i.e., a high interspersion of habitat types and abundant wild fruits and berries). Artificial food sources associated with urban and oilfield development may have led to decreases in the home range size of kit foxes in southwestern Kern County (Zoellick et al. 1987, Spiegel and Bradbury 1992).
Conversely, kit fox home ranges increased in size during times of low prey availability (White and Ralls 1993) and were negatively correlated with prey density (Morrell 1971, White and Garrott 1997). Thus, the small size of urban kit fox home ranges indicated that abundant food Table 9. Kit fox home range size reported within various habitats within their geographic range for comparison to home range size of urban kit foxes in Bakersfield, California from May 1997 to January 1998.
Reference Location Habitat Estimator Range Type Area km2 Knapp 1978 Kern County, CA Agriculture 100% Minimum convex polygona Home Range 2.52 Koopman 1995 Kern County, CA Saltbush scrub 100% Minimum convex polygon Home Range 3.52 Zoellick et al. 1987 Kern County, CA Saltbush scrub 100% Minimum convex polygon Home Range 4.63 White and Ralls 1993 Carrizo Plain, CA Grassland 100% Minimum convex polygon Home Range 11.60 O’Neal et al. 1987 Great Basin, UT Saltbush scrub 100% Minimum convex polygon Home Range 3.11 Spiegel and Bradbury 1992 Kern County, CA Saltbush scrub 97% Minimum convex polygonb Home Range 6.13 Spiegel and Bradbury 1992 Kern County, CA Saltbush scrub 95% Minimum convex polygonb Nocturnal Range 5.82 Hardenbrook 1987 Churchill County, NV Greasewood Modified Minimum Area Method Home Range 9.74 Arjo et al. 2003 Tooele County, UT Salt playa 95% Adaptive Kernel Home Range 43.09 Arjo et al. 2003 Tooele County, UT Greasewood 95% Adaptive Kernel Home Range 13.29 Arjo et al. 2003 Tooele County, UT Sagebrush 95% Adaptive Kernel Home Range 11.51 Koopman 1995 Kern County, CA Saltbush scrub 75% Harmonic Mean Core area 0.73 Spiegel and Bradbury 1992 Kern County, CA Saltbush scrub 50% Hamonic Meanb Core area 1.18 Zoellick et al. (2002) Kern County, CA Saltbush scrub 50% Hamonic Mean Core area 1.2 a May have been underestimated due to small sample size. b Estimates using non-independent data may have been inflated, as demonstrated in Koopman (1995). 47 48
resources were concentrated in key urban habitats around which home ranges were configured.
Further evidence of this was that urban kit foxes’ core area size constituted only 9% of the home range size, whereas that for rural kit foxes constituted 17% of the home range (Spiegel and Bradbury 1992). This may be because suitable denning habitat for urban kit foxes was concentrated around sumps and undeveloped lots.
Female urban kit foxes had a greater median number of core areas than did males, indicating that females had a higher number of distinct denning sites. Female kit foxes in Arizona (Golightly 1981) and Nevada (Hardenbrook 1987) spent more time near their dens than males. Fenced sumps in core areas provide denning habitat that may ensure safe reproduction in the urban population.
The home ranges and core areas of adjacent kit foxes may have substantial overlap if kit foxes are concentrated around limited resources (Golightly 1981), such as food-rich habitat patches (Macdonald 1983). Mean home range overlap was greater than 71% for family group members and less than 16% for unrelated individuals, which was less than that for the nearby rural population (Zoellick et al. 2002, Spiegel and Bradbury 1992).
Core area overlap was greater for members of the same family group (61%) than core area overlap of neighboring males and females (29%) or neighboring males (11%), similar to that for rural kit foxes (Spiegel and Bradbury 1992). Unpaired male and female urban kit foxes had a higher percentage of core area overlap than home range overlap. Because core areas were centered around denning sites, male and female kit foxes’ home ranges may have overlapped in a central denning area, as was the case for kit foxes in Arizona (Golightly 1981) and Nevada (Hardenbrook 1987). Kitchen et al.’s (2005) findings that male swift foxes spent more time on the boundary of the home range, while females spent more time in the group core area, may explain why female urban kit foxes had the least home range overlap and no core area overlap. 49 Overlap of home ranges and core areas indicated that kit foxes were concentrated around key urban habitat patches and food resources were not evenly-distributed. It was likely that urban kit foxes were able to find foraging and denning habitat in close proximity because of uniformlydistributed sumps, which may be important to the success of the urban kit fox population.
Due to refuse and human-derived foods, urban kit foxes may be able to meet their resource needs in a smaller area than rural kit foxes. The presence of these food resources distributed among disjunct habitat patches may explain why urban kit foxes had smaller and less overlapping home ranges than their rural counterparts. Given the constant and widespread availability of human-derived food in the urban landscape, suitable denning habitat may be a limiting factor for the urban kit fox population. This is consistent with Golightly’s (1981) conclusion that kit fox den sites in rural Arizona were limited by soils suitable for denning.
Estimates of 100% minimum convex polygon home range size were greater for males than females, perhaps due to fewer seasonal movements by females and increased foraging requirements for males during pup-rearing (Spiegel and Bradbury 1992). While Golightly (1981) found that male kit foxes in Arizona had much larger home ranges than females, home range size for other rural kit fox (Zoellick et al. 1987, Spiegel and Bradbury 1992, White and Ralls 1993, Koopman 1995), swift fox (Kitchen et al. 1999, Kamler et al. 2003), and Blanford’s fox (Vulpes cana; Geffen and Macdonald 1992) populations did not differ among the sexes.
Because home range size may vary with season (Burt 1943), the quantity of urban habitat needed to meet kit foxes’ ecological requirements may fluctuate over time. Home range size was greater for males than females during the breeding season, but did not differ between the seasons for kit foxes in Utah (Arjo et al. 2003), swift foxes (Kitchen et al. 1999), Blanford’s foxes (Geffen and Macdonald 1992), and culpeo foxes (Pseudalopex culpaeus; Salvatori et al. 1999).
In order to search for a mate during the breeding season, male foxes may increase their number of exploratory movements, which may be especially pronounced in the urban environment where 50 patches of habitat suitable to support kit foxes are small and disjunct. Home range size may have been underestimated during the pair formation and breeding seasons, because fewer kit foxes were located during this time. This may explain why mean home range size was significantly larger during the dispersal season than the pair formation and breeding seasons.
Habitat use
Habitats were known to be correctly classified for 68% of all independent locations, which were obtained by following the transmitted signal until the animal was observed or tracked to a den. It was unlikely that visually observed kit foxes were behaviorally pushed from one habitat to another, because kit foxes were resting or walking 67% of the time. However, distance between the animal and the radio-receiver, as well as broken topography, can increase telemetry error (Harris et al. 1990). Telemetry error was a concern because correct assignment of habitat use required accurate locations. Based on average telemetry error in urban coyote studies (Romsos 1998, Grinder and Krausman 2001), triangulated kit fox locations less than 100 m from the nearest habitat-patch edge may have been misclassified. The remaining 32% of locations were determined by triangulation or encircling the habitat patch. These locations averaged 31 m from the nearest habitat-patch edge and may have included some misclassification.
Like urban kit foxes, rural kit foxes do not use habitat within their home range in a uniform manner (Golightly 1981, Hardenbrook 1987) and have distinct core areas of concentrated activity (Koopman 1995). Kit foxes used open and sump habitats more than their availability in both the study area and in home ranges, and there was significantly more open and sump habitat in home ranges than in the study area. Likewise, urban red foxes (Sallee 1998) and coyotes (Romsos 1998) in Orange County, California used vacant field habitats more than expected. The higher vegetative cover in vacant fields may facilitate predator avoidance and support a more abundant prey base (Adams and Dove 1989) than the other less used urban habitats. Likewise, 51 sumps had marsh vegetation, which provides food and cover for wildlife and facilitates use by terrestrial wildlife (Adams and Dove 1989). Therefore, sumps may serve as artificial urban wetlands that provide denning habitat with their sloping sides, foraging opportunities based on the abundance of active small mammal burrows (personal observation), and a constant source of water, which I observed an urban kit fox drinking. In hot environments, such as Arizona, rural kit foxes meet their water needs through prey consumption (Golightly and Ohmart 1984). With the availability of free-standing water in the urban environment, kit foxes may require less food.
The number of people in the same habitat patch as the kit fox was lowest in open and sump habitats. While the greatest number of pedestrians observed along roads were near sumps, the fencing around sumps provided a physical and visual barrier between kit foxes and passing pedestrians. The shelter and security that the fenced perimeters provided may also explain why Stafford and Murphy (1992) found kit fox dens in 10 of the 95 sumps that they surveyed in Bakersfield. Likewise, urban red foxes disproportionate use of industrial habitats may be attributed to security personnel and perimeter fencing, which limited intrusion by humans and their pets (Sallee 1998).
There was significantly less residential habitat in urban kit fox home ranges than in the study area; the opposite was true for urban coyotes in Tucson, Arizona (Grinder and Krausman 2001). Harrison (1997) found that gray foxes (Urocyon cinereoargenteus) in New Mexico avoided high-density residential subdivisions. Urban coyotes (Romsos 1998) and red foxes (Sallee 1998) in Orange County, California avoided high-density residential and commercial habitats, perhaps due to a greater possibility for human and domestic animal interactions.
Likewise, Lucherini et al. (1995) found that red foxes used habitats with less human access and disturbance.
Industrial and linear habitats had a higher incidence of passing vehicles than all other habitats. This may be because industrial habitats tend to occur along major roads. In linear 52 habitat, from 1800 to 1859 h and 0700 to 0759 h, both the number of kit fox locations and number of passing vehicles peaked (Appendix E). However, during these times, 84% of the kit foxes using the linear habitat were located in dens that sheltered them from the disturbance of the passing vehicles.
The kit fox is one of the few canids that utilizes an underground den throughout the year (Berry et al. 1987, Koopman et al. 1998). Because dens are used for whelping and rearing pups, for escape cover from predators (Grinnell et al. 1937), and to minimize water loss and heat stress in summer and metabolic costs in winter (Golightly 1981, Golightly and Ohmart 1983), kit fox presence is limited by the availability of (Spiegel et al. 1996) or their ability to build dens. Like rural kit foxes in California (Knapp 1978, Berry et al. 1987, Reese et al. 1992) and Utah (Egoscue 1956, Arjo et al. 2003) and swift foxes (Kilgore 1969), urban kit foxes primarily used subterranean dens. However, they also used alternative dens, including pipes. Use of pipes that are known to interfere with radio signals, may have caused an underestimation of the number of alternative dens used in this study (Berry et al. 1987, Spiegel et al. 1996, Koopman et al. 1998).
Like Golightly (1981), I found that kit foxes did not randomly select den sites. Because kit foxes selected sump habitats for denning, there was more area of sump habitat in core areas than in home ranges. Sumps may also be used for denning because they are fenced and not accessible to the public. Likewise, most urban red fox dens occurred within fenced areas that may have isolated dens from human disturbance (Sallee 1998). Stafford and Murphy (1992) found that the majority of sumps used by urban kit foxes for denning were adjacent to undisturbed habitat, which likely has a low human presence.
Furthermore, I found that urban kit foxes denned in open habitats more than their availability in the study area. Likewise, rural kit foxes in California (Morrell 1971, Morrell 1972), Utah (Egoscue 1956, Egoscue 1962), and Arizona (Zoellick et al. 1989) and urban red 53 foxes (Lewis et al. 1993) frequently denned in flat, open areas. Kit foxes may be less vulnerable to coyote and bobcat predation on flat or rolling grasslands (Warrick and Cypher 1998).
Linear habitats (i.e., along canals, railroads, freeway embankments, and powerline rightof-ways) were used in proportion to their availability for denning. Like swift foxes, urban kit foxes utilized dens in road right-of-ways (Matlack et al. 2000). However, urban kit foxes denned near roads less than expected and in larger habitat patches than expected. Similarly, red foxes used habitats with less human access and disturbance for resting (Lucherini et al. 1995).
Movements
Kit foxes moved at an average rate of 1.33 km/h, nearly identical to that for kit foxes in southwestern Kern County (1.35 km/h; Koopman 1995) but slower than that for kit foxes in Arizona (males: 2.73 km/h; females: 1.49 km/h; Golightly 1981) and faster than that for swift foxes (males: 0.68 km/h; females: 0.59 km/h; Kitchen et al. 1999). Between dusk and dawn (i.e., approximately 10 to 14 h, depending on time of year), rural kit foxes in Arizona moved an average distance of 14.3 km for males and 11.8 km for females (Zoellick et al. 1989) and in southwestern Kern County, moved an average distance of 9.8 km for males and 10.9 km for females (Zoellick et al. 1987), yielding average movement rates similar to that for urban kit foxes.
The average distance that captured urban red foxes, raccoons, and skunks in Toronto, Canada moved from the point of release was less than that for their rural counterparts, which indicated that food and habitat in the urban environment were not limited in availability (Rosatte et al. 1991).
Males, which had larger 100% minimum convex polygon home ranges than females, may travel at higher rates of speed during the early part of the evening to cover their larger territory.
In Arizona, kit fox activity peaked in the early evening and a few hours before sunset, and males spent twice as much time out of the den, traveled 3.6 times farther, and maintained home ranges 54 2.6 times larger than females (Golightly 1981). However, in the urban setting, I did not detect a difference between sexes, movement session times, or their interaction with regard to maximum speed, mean speed, or total adjusted distance moved during each movement session. Similarly, lengths of nightly movements did not differ among sexes for rural kit foxes (Zoellick et al. 2002) and Blanford’s foxes (Geffen and Macdonald 1992). Compared to Arizona, where male kit foxes spent much time by the boundaries of their territory to defend a non-uniformly distributed resource base (Golightly 1981), urban kit foxes were able to meet their resource needs within small home ranges and did not need to travel far due to the concentration of resources within distinct habitat patches in the urban landscape.
Kit fox movement speed was not correlated with the number of passing vehicles, passing pedestrians, or people in the same habitat patch. This is consistent with the findings in Lewis et al. (1993), which indicated that urban red foxes were tolerant of humans. Nevertheless, kit foxes may have attempted to avoid human interactions by traveling at a high rate through residential, manicured open, and commercial habitats, all which had a high incidence of people.
Sump and transition habitats were typically small patches that were free of people at night when kit foxes were active. Kit foxes were observed foraging in and caching food scavenged from construction sites. Furthermore, the remains of several species that live in sumps, including bullfrog (Rana catesbeiana), burrowing owl (Athene cunicularia), duck (unidentified species), pocket gopher, squirrel, and opossum, were observed on kit fox dens in sumps (personal observation). Use of sump and transition habitats for hunting or scavenging refuse may explain why kit foxes traveled short distances at low speeds in these habitats.
Kit foxes used linear habitats (i.e., the Kern River Parkway, canals, and right-of-ways for highways, railroads, and powerlines) as corridors to move throughout their home range. Because highway, railroad, and powerline right-of-ways were fenced to prohibit public access, kit foxes may not have been compelled to move quickly through this habitat type. Kit foxes moved long 55 distances quickly through manicured open habitats, perhaps because this habitat had a high occurrence of humans and was used mostly as a corridor for traveling, similar to urban red foxes’ use of golf courses in Toronto, Canada (Rosatte et al. 1991).
Kit foxes in urban areas may have shorter nightly movements due to anthropogenic food sources (Zoellick et al. 1987). Consequently, movement distance may be influenced by foraging efficiency. Movement distance was less in commercial habitats (where kit foxes were observed foraging in parking lots and trash dumpsters) and transition habitats, both which tend to have an abundance of discarded food items (personal observation). Conversely, kit foxes moved longer distances in open, grassland habitat. This may have been because small, insectivorous prey of kit foxes and swift foxes tend to be evenly distributed in grassland habitats (Kamler et al. 2004).
Similarly, Koopman (1995) noted that food resources were uniformly distributed in rural kit fox home ranges.
Movements of kit foxes differed with regard to habitat type and time of night. From 1830 – 2230 h, linear habitat was used more than expected for kit fox resting/walking movements. This was probably because 23% of kit fox dens were in linear habitat. From 2230 – 0330 h, kit fox trotting and running movements were higher than expected in open habitat, which was likely used for foraging and traveling. From 2230 – 0330 h, kit fox resting/walking movements were less than expected in residential habitat, in which only one den was located. Kit foxes’ high rate of speed through residential habitat indicates that they used this habitat type as a means to get to a more used habitat. From 2230 – 0730 h, kit fox trotting movements were less than expected in sump habitat, which may be used primarily for denning rather than foraging.
From 0330 – 0730 h, industrial habitat was used less than expected for kit fox running movements. Kit fox speed may have been lower in industrial habitats during these hours due to the absence of humans or the presence of refuse.
56 Urban habitat was of sufficiently high quality to support kit foxes with low mortality and normal weight and offspring production. This was likely due to the widespread availability of natural and human-derived food sources and protected (i.e., fenced) areas with cover. Kit fox core areas contained a disproportionately high amount of sumps, which had food and den sites and restricted public access. The availability of sump and open habitats, which kit foxes selected for denning, may shape the distribution and abundance of the urban population. Portions of the urban landscape without these prime denning habitats may not be able to support kit foxes. 57 MANAGEMENT RECOMMENDATIONS
The kit foxes in Bakersfield had low mortality, similar weight and mean litter size, and high reproductive success, compared to that for rural kit foxes. Urban kit foxes appeared to have adapted to urban conditions and resources, and may contribute to the San Joaquin Valley metapopulation.
Urban kit foxes were observed crossing roads (up to four lanes), but also used culverts and a bridge to move under them, which may help explain the relatively low mortality. Vehicular mortality should be monitored around sump and open habitats. If increased mortality is observed, additional culverts may need to be placed and maintained under roads, along with animal-proof fencing to direct kit foxes to the culverts (Ng et al. 2004). Mid-sized mammals’ (i.e., raccoons and skunks) use of culverts is positively correlated to culvert length and negatively correlated to culvert area (Ng et al. 2004). Small diameter culverts (i.e., 0.5 m) may serve a dual purpose by providing a place for urban kit foxes to hide from larger predators and facilitating kit fox movement in a fragmented landscape.
To promote the continued existence of kit foxes in urban settings, such as Bakersfield, habitat will need to be retained and managed to meet their needs. Urban kit foxes denned farther from roads than expected in habitat patches that were larger than expected, and thus, may benefit from the retention of larger open and sump habitat patches for denning. Urban kit foxes had less spatial overlap and smaller home ranges and core areas than their rural counterparts. The greater presence of anthropogenic food sources in cities may enable urban kit foxes to meet their energetic needs in a smaller area than kit foxes in rural, grassland habitats, where food resources may be more dispersed (Kamler et al. 2004). Kit foxes utilized open lots and sumps more than all other urban habitat types.
58 Golightly (1981) concluded that dens were important to kit fox energetics and a consideration in the management of this species. If kit foxes are to be retained in Bakersfield, open lots, to provide foraging and denning habitat, and uniformly-distributed, sumps that are fenced and closed to the public, to provide kit fox denning habitat, will need to be maintained throughout the city. Sump maintenance (e.g., grading or paving) may be a potential hazard to kit foxes (Murphy 1992) and should be avoided. With sensitivity to kit fox presence in the urban environment, much protection can be afforded at a low cost.
The kit fox recovery strategy identified that “connections need to be established, maintained, and promoted between populations to counteract negative consequences of inbreeding, random catastrophic events (e.g., droughts) and demographic factors” (United States Fish and Wildlife Service 1998). Urban kit foxes used the Kern River Parkway to move throughout their home range. The Kern River Parkway should be maintained and managed to facilitate kit fox movement. In addition, dog management may be required because dogs may pose a threat to urban kit foxes as they have for rural kit foxes (Ralls and White 1995, Cypher et al. 2000).
Like urban red foxes in Great Britain (Kolb 1984) and Toronto, Canada (Rosatte et al. 1991) that use railroad corridors to move throughout their home range, urban coyotes (Romsos 1998), red foxes (Lewis et al. 1993, Sallee 1998), and kit foxes used canals (including foot bridges over canals) and railroad, highway, and powerline right-of-ways for moving and denning.
The continued existence of these right-of-ways, which are fenced to prohibit public access, will facilitate kit fox movement throughout the city. Kit foxes can persist in urban areas if an adequate mosaic of habitat is conserved and managed appropriately. 59 REFERENCES
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Warrick, G. D. and B. L. Cypher. 1998. Factors affecting the spatial distribution of a kit fox population. Journal of Wildlife Management 62: 707-717. 68 Whitaker, Jr., J. O. 1998. National Audubon Society field guide to North American mammals. 2nd edition. Alfred A. Knopf, Inc. New York, New York.
White, G. C. and R. A. Garrott. 1990. Analysis of wildlife radio-tracking data. Academic Press, Inc. San Diego, California.
White, G. C. and R. A. Garrott. 1997. Factors regulating kit fox populations. Canadian Journal of Zoology 75:1982-1988.
White, P. J. and K. Ralls. 1993. Reproduction and spacing patterns of kit foxes relative to changing prey availability. Journal of Wildlife Management 57:861-867.
White, P. J., K. Ralls, and D. B. Siniff. 2000. Nocturnal encounters between kit foxes. Journal of Mammalogy 81:456-461.
Wiens, J. A. 1973. Pattern and process in grassland bird communities. Ecological Monographs 43:237-270.
Winer, B. J., D. R. Brown, and K. M. Michels. 1991. Statistical Principles in Experimental Design, 3rd edition. McGraw-Hill, Inc. New York, New York.
Woodruff, R. A. and B. L. Keller. 1982. Dispersal, daily activity, and home range of coyotes in southeastern Idaho. Northwest Science 56:199-207.
Worton, B. J. 1989. Kernel methods for estimating the utilization distribution in home-range studies. Ecology 70:164-168.
Zoellick, B. W., C. E. Harris, B. T. Kelly, T. P. O'Farrell, T. T. Kato, and M. E. Koopman. 2002.
Movements and home range of San Joaquin kit foxes (Vulpes macrotis mutica) relative to oil-field development. Western North American Naturalist 62:151-159.
Zoellick, B. W., T. P. O'Farrell, and T. T. Kato. 1987. Movements and home range of San Joaquin kit foxes on the Naval Petroleum Reserves, Kern County, California. United States Department of Energy, Topical Report, EG&G/EM Santa Barbara Operations Report No. EGG 10282-2184, Santa Barbara, California. 38 pp.
Zoellick, B. W., N. S. Smith, and R. S. Henry. 1989. Habitat use and movements of desert kit foxes in western Arizona. Journal of Wildlife Management 53:955-961. 69 Appendix A. Sites of live-captured kit foxes, domestic cats, and opossums between May 1997 and January 1998 in Bakersfield, California.
Species captured
Habitat type Trap-nights Kit foxes Domestic cats Opossums Residential 5 1 0 0
Commercial 11 6 2 0
Industrial 41 13 5 0
Linear 84 19 3 1
Manicured open 53 21 0 0
Open 54 23 3 0
Sump 327 128 33 2
Total 575 211a 46 3
a Includes recaptures but excludes 32 captures which occurred when the number of traps in use was not recorded.
Appendix B. Kit fox location data and estimates for home range size, core area size, and time to independence for 28 radiocollared kit foxes that were monitored between May 1997 and January 1998 in Bakersfield, California.
Kit Fox Locations Home Range (km2)
Eartag Sex Sequential Daily Independent 100% MCP a 95% Fixed Kernel 50% Fixed Kernel
Core Area (km2) Time to Independence (h)
3468 F - 166 149 1.17 0.41 0.05 -
5468 F 190 193 166 1.36 0.94 0.08 1.69
5702 F 190 196 184 0.72 0.40 0.06 2.29
5703b F - 8 7 - - - -
5705 F - 183 163 2.71 2.70 0.20 -
5708 F 133 164 151 1.89 1.67 0.32 1.70
5713 F - 162 131 2.19 1.59 0.28 -
5723 F - 190 161 0.93 0.41 0.02 -
5741 F 166 181 174 1.32 0.66 0.08 3.89
5742 F - 213 177 2.69 2.78 0.43 -
5747 F 165 187 173 0.38 0.28 0.04 1.23
5752 F - 182 155 0.59 0.52 0.03 -
70 Appendix B. Kit fox location data and estimates for home range size, core area size, and time to independence for 28 radiocollared kit foxes that were monitored between May 1997 and January 1998 in Bakersfield, California (continued).
Kit Fox Locations Home Range (km2)
Eartag Sex Sequential Daily Independent 100% MCP a 95% Fixed Kernel 50% Fixed Kernel
Core Area (km2) Time to Independence (h)
5753 F - 198 162 1.07 0.67 0.06 -
5754 F - 79 64 1.63 2.75 0.32 -
5756 F - 189 164 0.36 0.35 0.07 -
5674 M 167 181 168 3.33 2.69 0.46 2.61
5701 M - 206 178 0.86 0.22 0.02 -
5704 M 230 203 193 2.16 2.40 0.39 1.80
5707 M - 179 160 2.70 2.50 0.50 -
5710 M 187 153 145 1.21 0.37 0.05 2.67
5711 M - 180 164 2.60 0.15 0.05 -
5712 M - 167 137 1.90 1.30 0.11 -
5721 M - 185 158 2.02 1.70 0.27 -
71 Appendix B. Kit fox location data and estimates for home range size, core area size, and time to independence for 28 radiocollared kit foxes that were monitored between May 1997 and January 1998 in Bakersfield, California (continued).
Kit Fox Locations Home Range (km2)
Eartag Sex Sequential Daily Independent 100% MCP a 95% Fixed Kernel 50% Fixed Kernel
Core Area (km2) Time to Independence (h)
5743 M 219 186 165 2.13 1.14 0.09 1.90
5744 M - 190 156 2.72 2.27 0.22 -
5746 M - 176 147 0.31 0.04 0.01 -
5755 M 163 168 154 1.11 0.30 0.03 1.74
5757 M - 159 143 4.49c 15.58d 4.00d-
Total 1810 4824 4249 - - - -
Mean 181 172.3 151.75 1.72 1.2 0.16 2.15
SE 9.04 7.62 6.89 0.19 0.19 0.03 0.24
a Minimum convex polygon.
b
Located too few times to be included in the home range and habitat use analyses. c Sum of two distinct home ranges in the southeastern (3.19 km2 ) and northwestern (1.31 km2) parts of the study area, approximately 3.1 km apart.
d Outlier that was excluded from calculation of x¯ + 1 SE. 72 Appendix C. Weight, hind foot, and ear measurements for captured adult, subadult, and pup kit foxes in Bakersfield, California between May 1997 and January 1998.
Male Female
Body Measurement Age n x¯ SE n x¯ SE Statistica p
Weight (kg) Adult 29 2.47 0.05 32 2.16 0.03 t = -5.53 <0.001 Subadult 7 2.09 0.11 6 1.87 0.14 t = -1.29 0.22
Pup 20 1.73 0.04 13 1.44 0.05 t = -4.25 <0.001
Hind foot (mm) Adult 27 125.5 1.0 31 119.8 0.8 t = -4.4 <0.001 Subadult 6 121 1.2 5 118.4 0.9 t = -1.67 0.13
Pup 18 121 1.2 9 112.2 1.4 t = -4.36 <0.001
Ear from notchb (mm) Adult 28 81.4 0.6 31 78.6 0.7 z = 3.28 <0.001 Subadult 6 82.5 0.6 5 78.4 1.3 t = -3.04 0.007
Pup 19 80.1 0.8 10 75.3 1.1 t = -3.65 <0.001
Ear from rearc (mm) Adult 28 84.4 0.7 31 81.5 0.7 t = -2.81 0.002 Subadult 6 84.8 1.1 5 81.2 2.2 t = -1.56 0.15
Pup 19 80.8 0.8 10 77.1 1.1 t = -2.6 0.007
a
I used a 2-sample t-test to determine if means differed between the sexes. For data that was not normally distributed, I used a Mann-Whitney U-test to determine if medians differed between the sexes. b Tip of ear to notch at anterior base.
c Tip of ear to posterior base.
73 74
Appendix D. Area-observation curves using the 100% minimum convex polygon home range for 27 kit foxes in Bakersfield, California from May 1997 to January 1998.
Females
0 0.5
1 1.5
2 2.5
3 3.5
4 0 20 40 60 80 100 120 140 160 180
Home Range Area (km
2)
3468 5468 5702 5705
5708 5713 5723 5741
5742 5747 5752 5753
5754 5756
Males
0 2
4 6
8 10
12 14
16 0 20 40 60 80 100 120 140 160 180 200
Number of Locations
Home Range Area (km
2)
5674 5701 5704
5707 5710 5711
5712 5721 5743
5744 5746 5755
5757
Appendix E. The percentage of all radiocollared kit fox daily locations (n = 4,824) and passing vehicles documented in linear habitats during each hour in Bakersfield, California from September 1997 to January 1998. 0 2
4 6
8 10
12 14
16 1500-1559 1600-1659 1700-1759 1800-1859 1900-1959 2000-2059 2100-2159 2200-2259 2300-2359 0000-0059 0100-0159 0200-0259 0300-0359 0400-0459 0500-0559 0600-0659 0700-0759 0800-0859 0900-0959 Time Percent
Kit Fox Locations in Linear Habitat
Vehicles Passing on Nearest Road
75 EXHIBIT E
April 15, 2026
Via email: [email protected]
City Council of the City of Bakersfield
City Hall
1501 Truxtun Avenue
Bakersfield, CA 93301
Re: Applicant’s response to appeal of Vesting Tentative Tract Map 7500 Dear Honorable Councilmembers:
On behalf of the applicant for Vesting Tentative Tract Map 7500 (the “project”), McIntosh & Associates, we submit this response to the appeal filed by Supporters Alliance for Environmental Responsibility (“SAFER”), challenging the August 21, 2025, approval of the project by the City Planning Commission.
SAFER demands that a new environmental impact report (EIR) or mitigated negative declaration (MND) be prepared for the project, alleging that additional analysis is required to consider potential impacts to biological resources and air quality. SAFER is wrong—no further environmental review is required, because the previously adopted MND on which the City relies remains applicable and relevant, and there are no substantial changes to the original project, no substantial changes in circumstances under which the project will be undertaken, and no new environmental impacts have been identified which would trigger the need for additional environmental review under CEQA.
Background
The project proposes a vesting tentative tract map for 208 single-family residential lots on
39.92 acres in the City of Bakersfield. In 2007, the City began the process of authorizing residential development at the site, and in 2008, the City Council approved a General Plan Amendment and Zone Change and an associated MND.
On August 21, 2025, the Planning Commission unanimously approved the project, finding that no further environmental documentation was necessary because no new, or substantially more severe, significant impacts will result from the proposed project compared to those previously Sabrina V. Teller
[email protected]
Applicant’s Response to Appeal re: VTTM 7500
April 15, 2026
identified in the MND for the General Plan Amendment and Zone Change. SAFER appealed the Planning Commission’s approval, arguing that the City’s reliance on the 2007 MND violated CEQA due to potential significant impacts not previously considered, or new information or changed circumstances that would require the preparation of a new MND. SAFER’s appeal should be denied for the following reasons.
The expiration of the Metropolitan Bakersfield Habitat Conservation Plan (MBHCP) is not a changed circumstance requiring major revisions to the MND.
SAFER contends that the expiration of the MBHCP constitutes a “changed circumstance” requiring supplemental review. This is incorrect.
Subsequent review due to changed circumstances is required if “substantial changes occur with respect to the circumstances under which the project is undertaken which will require major revisions of the previous EIR or negative declaration due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects.” (CEQA Guidelines, § 15162, subd. (a)(2).) In other words, the change must cause new or more severe impacts that would require “major revisions” to the existing environmental document. (Friends of College of San Mateo Gardens v. San Mateo County Community College Dist. (2016) 1 Cal.5th 937, 959 (San Mateo Gardens).) The expiration of the MBHCP by itself does not mandate additional environmental analysis.
Courts have been clear that changes to regulations and guidelines that are adopted after an environmental document is certified do not trigger supplemental review. (Fort Mojave Indian Tribe v. California Department of Health Services (1995) 38 Cal.App.4th 1574, 1605; Concerned Dublin Citizens v. City of Dublin (2013) 214 Cal.App.4th 1301, 1320; Olen Properties Cort. v. City of Newport Beach (2023) 93 Cal.App.5th 270, 280; Cleveland National Forest Foundation v. San Diego Assn. of Governments (2017) 17 Cal.App.5th 413, 426.) As the court stated in Olen Properties, supra, 93 Cal.App.5th: “Indeed, the rule could hardly be any different—if every change to guidelines constituted “new information,” section 21166 would require a new EIR nearly every time any change is made to a project, no matter how inconsequential.” (Id. at p. 281.) To trigger supplemental review, SAFER would need to point to substantial evidence showing that the MBHCP’s expiration has demonstrable adverse impacts on species. SAFER does not meet this burden.
SAFER argues that the MBHCP’s expiration will cause new environmental impacts because “the City can no longer rely on the MBHCP’s mitigation framework to offset impacts to special-status species covered under the plan.” (Oct. 21, 2025, letter from SAFER to Planning Commission, p.
5.) Specifically, there is no longer a mitigation fee program for the project to pay into. (Ibid.) This framing suggests that the MBHCP itself implemented mitigation for impacts to specialstatus species. The MBHCP, however, merely provided incidental take coverage under the federal and California Endangered Species Act for qualifying projects. (City of Bakersfield, Applicant’s Response to Appeal re: VTTM 7500
April 15, 2026
“Report on the status of efforts toward adoption of a new Habitat Conservation Plan, implications of expiration of the Metropolitan Bakersfield Habitat Conservation Plan, and request for City Council direction” (Oct. 5, 2022).) Its expiration means that there is no longer take coverage for vested maps, and therefore compliance with the Endangered Species Acts is the responsibility of the landowner. (Ibid.) SAFER expresses concern that without take permits, the project could result in unauthorized take of state and federally listed species. (Oct. 21, 2025, letter from SAFER to Planning Commission, p. 6.) Without take permits, however, the project is prohibited from any take of listed species, meaning protections for listed species remain in place. Further, the 2024 MESA Biological Special Status Species Survey (“2024 survey”) and 2025 Pruett Biological Resource Consulting Biological Resource Evaluation (“2025 evaluation”) support the City’s determination that the project will not result in unauthorized take or cause other significant adverse impacts on biological resources. The 2024 survey found no evidence of special-status species at or adjacent to the project site. (MESA Biological Special Status Species Survey, p. 3.) The 2025 evaluation concluded that the project is not expected to have an adverse impact on special-status species. (Pruett Biological Resource Consulting Biological Resource Evaluation, p. 7.)
SAFER points to the San Joaquin kit fox (SJKF) as an example of a special-status species previously protected under the MBHCP. It states, “the expiration of the MBHCP means there is no longer any protection for [SJKF], which may be significantly impacted by the Project’s construction.” (Oct. 21, 2025, letter from SAFER to Planning Commission, p. 5.) First, this mischaracterizes the regulatory structure for threatened and endangered species, which remain protected by federal and state laws despite the expiration of an HCP. Second, SAFER does not point to any evidence that there will be adverse impacts to SJKF individuals or habitat at the project site. Instead, SAFER’s argument is based on three studies—two from the United States Fish and Wildlife Service (USFWS) and one from the California Department of Fish and Wildlife (CDFW)—that generally assess the status of SJKF. No source identifies SJKF individuals or habitat at the project site, nor demonstrates that the MBHCP is integral to the species’ continued survival. Further, the CDFW source was published in 2005 and therefore was in existence when the 2007 MND was adopted, meaning that it necessarily cannot illustrate a “changed circumstance” since the previous environmental analysis. By contrast, the latest expert studies of the project site provide substantial evidence for the City’s conclusion that the project changes will not cause new or substantially more severe impacts to SJKF. (MESA Biological Special Status Species Survey, p. 3; Pruett Biological Resource Consulting Biological Resource Evaluation, p. 7.)
Lastly, SAFER recommends USFWS standardized recommendations for SJKF individuals or dens discovered during construction. Although the surveys conducted by the City did not find evidence of SJKF individuals or dens at the project site, the 2025 evaluation confirms that those USFWS recommendations will be implemented if SJKF are discovered any time during construction. (Pruett Biological Resource Consulting Biological Resource Evaluation, p. 7.) Applicant’s Response to Appeal re: VTTM 7500
April 15, 2026
Overall, SAFER does not demonstrate that the MBHCP’s expiration is a substantial change in circumstances resulting in significant biological resources impacts.
The listing status of special-status species are not changed circumstances requiring major revisions to the MND.
SAFER alleges that newly listed special-status species represent a significant change in circumstances requiring an updated analysis of biological resources impacts. (Oct. 21, 2025, letter from SAFER to Planning Commission, p. 6.) SAFER states the project cannot rely on the 2007 MND for these impacts because there is “a fair argument that the Project may have new significant impacts.” (Ibid.)
As explained by the Supreme Court, “[o]nce a project has been subject to environmental review and received approval, [CEQA] limit[s] the circumstances under which a subsequent or supplemental EIR must be prepared. These limitations are designed to balance CEQA’s central purpose of promoting consideration of the environmental consequences of public decisions with interests in finality and efficiency.” (Friends of College of San Mateo Gardens v. San Mateo County Community College Dist. (2016) 1 Cal.5th 937, 949 (San Mateo Gardens).) In considering whether supplemental review is required for a project originally approved with a negative declaration, a challenger must provide substantial evidence that new significant impacts are caused by a project change, changed circumstances, or new information. Importantly, supplemental review is not an opportunity to reopen the environmental analysis in the underlying environmental document. (Megaplex-Free Alameda, supra, 149 Cal.App.4th at p. 110, citing Temecula Band of Luiseno Mission Indians v. Rancho California Water Dist. (1996) 43 Cal.App.4th 425, 430, fn. 3.)
Fatally for SAFER’s claims here, it does not present any evidence of changed circumstances triggering supplemental review. The listing of a special-status species does not justify further environmental review. “Without information indicating the species may be found within or near the project, such a listing alone does not constitute substantial evidence of significant impacts justifying further environmental review under section 21166.” (Moss v. County of Humboldt (2008) 162 Cal.App.4th 1041, 1065 (Moss).) In Moss, supra, the court found no evidence that the project would have an impact on the newly-listed coho salmon. Since “the only thing that [] changed since the previous study… [was] that Northern California coastal coho salmon [were] identified as a threatened species,” the conditions triggering supplemental review were not met. (Ibid.) Since the listing of new species itself does not constitute a changed circumstance, SAFER would need to demonstrate that there is some other qualifying project change or new information. Neither SAFER’s letter nor Dr. Smallwood’s testimony present substantial evidence of a project change, changed circumstance, or new information triggering supplemental review.
Applicant’s Response to Appeal re: VTTM 7500
April 15, 2026
On the other hand, substantial evidence supports the City’s determination that the project will not cause adverse impacts on special-status species. The 2024 survey found no evidence of special-status species at or near the project site. (MESA Biological Special Status Species Survey, p. 3.) The 2025 evaluation concluded that the project is not expected to have an adverse impact on special-status species. (Pruett Biological Resource Consulting Biological Resource Evaluation, p. 7.) Thus, SAFER does not demonstrate that additional environmental review is necessary due to newly-listed special-status species.
The City Council has substantial evidence to support its determination that no further environmental review of biological resources is necessary.
SAFER contends that the City does not have substantial evidence to support its conclusions because the City never prepared an expert analysis of the 2007 project’s impacts, nor did so for the current project.
First, SAFER’s window to challenge the conclusions in the 2007 MND expired nearly two decades ago. Once the statute of limitations for a CEQA document has expired, any challenges to later approvals “are ‘limited to the legality of the agency’s decision about whether to require a subsequent or supplemental [environmental document], and the underlying EIR or negative declaration may not be attacked.’” (Megaplex-Free Alameda, supra, 149 Cal.App.4th at p. 110, citing Temecula Band of Luiseno Mission Indians v. Rancho California Water Dist. (1996) 43 Cal.App.4th 425, 430, fn. 3.) Thus, SAFER may not challenge the 2007 MND’s conclusions.
Second, SAFER is incorrect that the City did not rely on substantial evidence to support its conclusions regarding the project’s impacts on biological resources. As discussed above, the 2024 survey and 2025 evaluation conclude that the project will not cause new or more severe environmental impacts. (MESA Biological Special Status Species Survey, p. 3; Pruett Biological Resource Consulting Biological Resource Evaluation, p. 7.) The 2024 survey was conducted by field survey, performed by a CDFW Approved Qualified Wildlife Biologist experience with regionally occurring animal and plant species, natural communities, and field survey methodologies. (MESA Biological Special Status Species Survey, p. 1.) The 2025 evaluation included a literature review, based on five federal and state databases, and a field study. (Pruett Biological Resource Consulting Biological Resource Evaluation, p. 2.) On the other hand, SAFER relies on Dr. Smallwood’s assessment, which did not involve a field study and seems to query just one database. (Oct. 21, 2025, letter from SAFER to Planning Commission, Exh. A, p. 3.) Beyond citing to the eBird/iNaturalist records, Dr. Smallwood does not reveal the source of the data, such as who conducted any surveys, the dates surveys were conducted, or the credibility of the sources. Without such information, Dr. Smallwood’s assessment does not constitute substantial evidence. (CEQA Guidelines, § 15384, subd. (a) [“Argument, speculation, unsubstantiated opinion or narrative, evidence which is clearly erroneous or inaccurate, . . . does not constitute substantial evidence.”].) Further, although the Applicant’s Response to Appeal re: VTTM 7500
April 15, 2026
assessment cites a plethora of studies and articles, none are specific to the project site. (Oct. 21, 2025, letter from SAFER to Planning Commission, Exh. A, pp. 9-10.) (See Save the Plastic Bag Coalition v. City of Manhattan Beach (2011 52 Cal.4th 155, 175 [generic studies “must be kept in proper perspective and not allowed to swamp the evaluation of actual impacts attributable to the project at hand.”].) The evidence SAFER presents does not demonstrate that there are changed circumstances at or around the project site requiring supplemental review.
The project will not cause new cumulative impacts due to regional urbanization.
SAFER briefly argues, without citing to any evidence, that urbanization and conversion of open space and agricultural lands that has occurred in the past decade renders the 2007 MND inapplicable. However, the 2024 survey and 2025 evaluation demonstrate that the site does not currently contain habitat. (MESA Biological Special Status Species Survey, p. 3; Pruett Biological Resource Consulting Biological Resource Evaluation, p. 7.) Thus, the record before the City Council does not demonstrate that the project will result in cumulative habitat loss.
The project has not substantially changed compared to the project assessed in the 2007 MND.
SAFER contends that the increase of proposed units from 172 to 208 constitutes a “substantial change” requiring “major revisions” to the MND. We disagree.
Once again, the standard for supplemental review requires that there is a project change, changed circumstance, or new information, and that such change is significant enough to require major revisions to the MND. When considering whether subsequent review is necessary, the question is “whether circumstances have changed enough to justify repeating a substantial portion of the process.” (Committee for Green Foothills v. Santa Clara County Bd. of Supervisors (2010) 48 Cal.4th 32, 55.) “When circumstances change in a relatively minor fashion or do not cause any significant impacts other than those already contemplated by the [environmental document], CEQA does not require [additional environmental analysis].” (A Local & Regional Monitor v. City of Los Angeles (1993) 12 Cal.App.4th 1773, 1803.) SAFER does not explain why an increase of just 36 units would so substantially increase air quality impacts that the previously adopted mitigation measures and conditions of approval are no longer adequate to mitigate impacts.
SAFER cites to an assessment conducted by SWAPE. (Oct. 21, 2025, letter from SAFER to Planning Commission, Exh. B.) The assessment, however, does not demonstrate that the change in units will cause new or substantially more severe impacts. In fact, the short assessment does not include any data or evidentiary basis for its claims. (Ibid.) Instead, it essentially attempts to make the legal argument that the Staff Report does not demonstrate that the project will not have new significant impacts. This does not qualify as affirmative substantial evidence of new impacts, as CEQA requires. (CEQA Guidelines, § 15384, subd. (b) Applicant’s Response to Appeal re: VTTM 7500
April 15, 2026
[defining “substantial evidence” as “facts, reasonable assumptions predicated on facts, and expert opinion supported by facts.”].)
The City Council has substantial evidence to support its determination that no further environmental review of air quality impacts is necessary.
SAFER argues, as it did for biological resources, that there is no substantial evidence to support the City’s air quality findings. However, the City’s conclusions are in fact supported by substantial evidence. In particular, the Trinity Consultants Air Quality Impact Analysis concluded that the project would result in less than significant impacts to air quality, health risks, and greenhouse gas emissions. (Trinity Consultants Air Quality Impact Analysis, p. 1-1.) Additionally, the project incorporates mitigation measures and conditions of approval, which provides further substantial evidence that the project will not result in new or substantially more severe environmental impacts. This includes nearly three pages of mitigation measures that the project will implement. (City of Bakersfield Planning Commission Staff Report (Aug. 15, 2025, pp. 27-29.)
Beyond the SWAPE assessment, SAFER cites to general statistics about air quality in Bakersfield.
However, it again fails to illustrate how the project change (an increase of just 36 units) will cause substantially more severe impacts as compared to those considered in the 2007 MND.
Since supplemental review is not an opportunity to reopen or reconsider the previous environmental analysis, SAFER does not present any evidence to disrupt the City’s conclusion regarding air quality impacts.
We respectfully request that the Council deny the appeal and approve the tentative map.
Very truly yours,
Sabrina V. Teller
Attachment A: Nov. 26, 2025, Pruett Biological Consulting Services report Attachment B: May 31, 2024, MESA Biological LLC report
Attachment C: Feb. 2026, Trinity Consultants Air Quality Impact Analysis cc: Noeli Topete, [email protected]
Jennie Eng, [email protected]
Phil Burns, [email protected]
Blaine Neptune, [email protected]
Attachment A
BIOLOGICAL RESOURCE EVALUATION
General Plan Amendment/Zone Change
Assessor’s Parcel Map Number
540-010-19
Vesting Tentative Tract Number
7500
County of Kern
Bakersfield, California
Prepared for:
Old River TIC
PO Box 11358
Bakersfield, California 93389
Prepared by:
Pruett Biological Resource Consulting
8819 Latera Court
Bakersfield, California 93314
661.421.0006
November 26, 2025
Biological Resource Evaluation
APN 540-010-19
November 2025
EXECUTIVE SUMMARY
Pruett Biological Resource Consulting, Inc. (PruettBio) has prepared this biological resource evaluation for a proposed Site Plan Review of Assessor’s Parcel Number (APN) 540-010-19. The project consists of
39.92 gross acres (16.16 hectares) (project) Section 29, Township 30 South, Range 27 East, Mount Diablo Base and Meridian. The project is located northeast of the intersection of Old River Road and McCutchen Road, within the incorporated limits of the City of Bakersfield, County of Kern, California.
The project is located within the geographic range of several federal-, and state-listed, threatened and/or endangered plant and animal taxa. Several non-listed, special-status species also have the potential to occur in the vicinity of the project.
The purpose of this report is to document biological resources identified during a reconnaissance-level field study of the project site and include potential biological resources identified during a literature review of the site and vicinity, identify potential impacts to biological resources resulting from the project.
Evaluation of potential impacts to plant and animal species are required under federal and state regulation during a General Plan Amendment and Zone Change. California Environmental Quality Act (CEQA) Appendix G thresholds have been used to evaluate potential impacts to biological resources from the proposed project development. Avoidance and minimization measures for implementation prior to and during project activities are recommended as appropriate.
The California Department of Fish and Wildlife (CDFW) and United States Fish and Wildlife Service (USFWS) have not been contacted regarding the preparation of this report. Appendix B, Special-Status Plant and Animal Evaluations, satisfy the requirements for an initial determination of potential impacts under the CEQA Appendix G thresholds. If CEQA threshold determinations warrant, further consultation may be required with CDFW and USFWS. If additional consultation with the agencies results in the need for Application for a California Incidental Take Permit, Cal. Code Regs., tit. 14, § 783.2 outlines requirements for detailed species-specific take analysis, proposed measures to minimize and fully mitigate impacts, compliance monitoring, and funding. A detailed description satisfying Cal. Code Regs., tit. 14, § 783.2 is not required to meet the CEQA Appendix G thresholds.
A literature review was conducted of the site and vicinity, prior to the field study, of the biological resources known to occur based on recorded, direct observation, or potentially occurring in the project impact area based on current or historical habitat conditions. During the field study, existing habitat conditions, direct observations and/or species sign were recorded to assess the potential for occurrence of special-status species. This report includes an evaluation of the potential for those special-status biological resources not observed during the field study, with the potential to occur on the property based on the habitat conditions observed.
The project is in southwest Bakersfield in an area historically farmed. Urban development has increased along the margins of Metropolitan Bakersfield in the past 50 years and has resulted in the conversion of farmland to residential and commercial properties. The project includes solely recently disced vacant land. The project is surrounded by single-family residential development, intensive agricultural production (orchards), and a public high school. No undisturbed, native, or recovering habitat is present on the site or adjacent parcels.
The federal and state database queries yielded 21 special-status plant species and 34 special-status animal species as potentially occurring within the vicinity of the project site. Of these, 5 plant species, and 16 animal species have federal-, and/or state-listing and are afforded protection under federal or state law.
A query of the California Native Plant Society (CNPS) database was made for the quadrangle in which the project exists and the eight-quadrangles surrounding the project. The CNPS tracks plant species that Biological Resource Evaluation
APN 540-010-19
November 2025
do not meet the CEQA Section 15380 criteria for listing as threatened or endangered and are afforded no protection under federal or state law. A United States Geologic Service (USGS) nine-quadrangle query additionally includes a search area beyond a standard 10-mile radius. Plant species meeting the criteria for Special Status Plants as defined in Protocols for Surveying and Evaluating Impacts to Special Status Native Plant Populations and Sensitive Natural Communities (CDFW 2018) and evaluated under CEQA Section 15380 have been included in this report.
Some California Rare Plant Rank (CRPR) 4 taxa may meet the Section 15380 definition of an endangered, rare, or threatened species, and in the definition of CRPR 4, CNPS and CDFW suggest additional reasons for including CRPR 4 taxa in a CEQA analysis. These reasons include Regionally Rare Taxa. Considered locally significant plants, that is, plants that are not rare from a statewide perspective but are rare or uncommon in a local context such as within a county or region (CEQA Guidelines, § 15125, subd. (c)), or as designated in local or regional plans, policies, or ordinances (CEQA Guidelines, Appendix G). “Locally rare” has not been generally defined, but in counties where a “locally rare” policy exists, it applies to taxa with only five to 10 known occurrences in that county.
The California Natural Diversity Database (CNDDB), Information for Planning and Consultation (IPaC), and CNPS lists were cross-referenced for consistency. A separate CNDDB query for the County of Kern was also generated to evaluate plant species for local significance.
No special-status animals or plants were observed during the field study. Although no evidence of special-status animal species was observed during the field study, given known distribution and movement, development of the proposed project could result direct and indirect impacts, in the form of “incidental take” of a threatened, endangered, or otherwise protected species. The proposed project will not have a substantial adverse effect on any riparian habitat, federally protected wetlands, native resident or migratory wildlife corridors, or other sensitive natural community. The project will not conflict with existing or adopted Habitat Conservation Plans, Natural Community Conservation Plans, local or regional conservation plans, or local ordinances protecting biological resources.
Biological Resource Evaluation
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Table of Contents
INTRODUCTION ..................................................................................................................................................... 1 PROJECT LEGAL DESCRIPTION ................................................................................................................................... 1 PROJECT SETTING AND PHYSICAL DESCRIPTION ....................................................................................................... 1 METHODS .............................................................................................................................................................. 2 LITERATURE REVIEW ................................................................................................................................................. 2 FIELD STUDY .............................................................................................................................................................. 2 RESULTS ................................................................................................................................................................. 3 VEGETATION COMMUNITIES AND LAND COVER ....................................................................................................... 3 SOILS ......................................................................................................................................................................... 3 BIOLOGICAL RESOURCES ........................................................................................................................................... 3 Special-Status Plant Species ................................................................................................................................. 4 Special-Status Animal Species .............................................................................................................................. 5 Designated Critical Habitat .................................................................................................................................. 5 Jurisdictional Water Resource Features ............................................................................................................... 5 Special-Status Natural Communities .................................................................................................................... 5 Wildlife Migration Corridors and Nursery Sites .................................................................................................... 5 Regional and Local Policies .................................................................................................................................. 6 IMPACT ANALYSIS AND RECOMMENDED MITIGATION MEASURES ........................................................................ 6 RECOMMENDED MITIGATION MEASURES ................................................................................................................ 8 REFERENCES ......................................................................................................................................................... 10 APPENDIX A ......................................................................................................................................................... 13 PROJECT VICINTY AND SITE ..................................................................................................................................... 13 APPENDIX B ......................................................................................................................................................... 18 SPECIAL-STATUS PLANT AND ANIMAL EVALUATION ............................................................................................... 18 APPENDIX C ......................................................................................................................................................... 37 PLANTS AND ANIMALS OBSERVED ON THE PROJECT .............................................................................................. 37 Biological Resource Evaluation
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1 INTRODUCTION
Pruett Biological Resource Consulting, Inc. (PruettBio) has prepared this biological resource evaluation for the proposed development of APN 540-010-19. The project consists of 39.92 gross acres (16.16 hectares) (project) Section 29, Township 30 South, Range 27 East, Mount Diablo Base and Meridian. The project is northeast of the intersection of Old River Road and McCutchen Road, within the incorporated limits of the City of Bakersfield, County of Kern, California. The report documents biological resources identified during fieldwork conducted on the project site and those identified through a literature search as potentially occurring based on known observations or historic habitat conditions. The report uses the information collected during the field study and literature search to evaluate potential impacts to biological resources, resulting from the project. The report is intended to assist in the analysis of the proposed project for a Site Plan Review.
Listed plant and animal species are protected under the Federal Endangered Species Act (FESA) and the California Endangered Species Act (CESA). Protection of other non-listed, special-status species is afforded under additional regulation including the Migratory Bird Treaty Act (MBTA). Pursuant to the California Environmental Quality Act (CEQA) impacts to non-listed, special-status species must be evaluated. Where necessary, the report recommends avoidance and minimization measures for implementation prior to and during project activities. The report is intended to provide technical information in support of a CEQA preliminary review. For the purposes of this report, potential impacts to the biological resources of the proposed project were evaluated in accordance with Appendix G of the CEQA Guidelines (2025).
PROJECT LEGAL DESCRIPTION
The project consists of 39.92 gross acres (16.16 hectares) of APN 540-010-19. The project site is located northeast of the intersection of Old River Road and McCutchen Road, Section 29, Township 30 South, Range 27 East, Mount Diablo Base and Meridian.
PROJECT SETTING AND PHYSICAL DESCRIPTION
The project site is in the southern San Joaquin Valley; a broad, treeless plain in the rain shadow of the Inner Coast Ranges. The region’s climate can be characterized as Mediterranean; with hot, dry summers and cool, moist winters. Summer high temperatures typically exceed 100 °Fahrenheit (°F); with an average of 110 days per year over 90 °F. Winter temperatures in the San Joaquin Valley are mild, with an average of only 16 days per year with frost (Twisselmann 1967).
Rainfall varies, increasing from west to east, with the west side of the valley receiving an average of around 4 inches (10 centimeters) per year and the east side averaging about 6 inches (15 centimeters) per year. Winter fog, called Tule fog, sometimes forms during the months of November, December, and January, supplementing the annual precipitation. Approximately 90% of the rainfall in the region occurs between November 1 and April 1. Drought cycles occur periodically, becoming severe enough that plant and animal populations can experience large fluctuations. The vegetation communities in the San Joaquin Valley are distinguishable from the Mojave Desert to the east due to Tule fog, higher humidity, and isolation from continental climatic influences by mountain ranges (Twisselmann 1967).
The general topography of the project area is generally flat at about 345 feet (105 meters) above mean sea level. The project includes solely vacant land that was previously intensive agriculture and recently disced at the time of the field study. The project is surrounded by single-family residential development, intensive agricultural production (orchards), and a public high school. The project and vicinity were historically farmed for decades. Historical aerial imagery going back to 1985 shows the project and much of the surrounding land under row crops. Aerial imagery shows that by 2008, construction of Independence High School located west of the project began. From 2003 to 2020, intensive agriculture to the north and northeast was converted into single-family homes. In 2023, a residential development immediately east of the project began and was still under development at the time of this report. No undisturbed, native, or recovering habitat is present on the project site or adjacent parcels.
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2 METHODS
LITERATURE REVIEW
PruettBio conducted a literature review to identify known observations and potential for listed, or otherwise special-status, species to occur in the vicinity of the project site. A standard, 10-mile (16- kilometer) radius query was performed. Database records reviewed included:
United States Fish & Wildlife Service (USFWS) IPaC: The IPaC report generates a list of federal-listed species and other resources under the jurisdiction of the USFWS, including designated critical habitat for listed species, National Wildlife Refuge lands, and Wetlands in the National Wetlands Inventory. The list includes resources that are outside of the project site, but that have the potential to be impacted by project activities. USFWS National Wetlands Inventory: The Wetlands Mapper is an online inventory integrating digital map data and other resources to provide current information regarding the status of national wetlands, riparian, and deepwater habitats.
United States Department of Agriculture (USDA) WebSoil Survey: The report is an online database providing soil data produced by the National Cooperative Soil Survey, a joint effort of the USDA and other federal, state, and local agencies. The information drawn for the Soil Survey of Kern County, California, Northwestern Part was originally drawn from fieldwork completed in 1981 with soil names and descriptions approved in 1982. California Natural Diversity Database (CNDDB-RareFind 5): The CNDDB is a database of listed, or otherwise special-status, plant and animal species and sensitive communities maintained by the California Department of Fish and Wildlife (CDFW). The information queried for this report included a standard 10-mile radius of the project site. California Native Plant Society (CNPS) Inventory of Rare and Endangered Vascular Plants:
CNPS is a private, professional organization that maintains a database evaluating the current conservation status of California’s rare, threatened, and endangered plant species. The information queried for this report included a standard 10-mile radius of the project site. The list includes resources that are outside of the project site, but that have the potential to be impacted by project activities based on known historic or current habitat features. The database was compared to the CNDDB and IPaC queries for consistency.
FIELD STUDY
A reconnaissance-level, biological field study was conducted by Jacob Spriester on November 14, 2025.
The project was surveyed by walking the perimeter. The project area showed signs of recent discing within the past couple months, and survey efforts were focused on areas that were not heavily disturbed.
Binoculars were used to survey the disced areas from the perimeter. A 50-foot survey buffer, beyond the anticipated project footprint, was included as accessible. The field study conducted, allowed for maximum visual coverage of the project site. Field notes included observations of all plant and wildlife species observed. Direct observations and/or species sign was recorded to assess the potential for occurrence.
Land cover types and general habitat conditions were recorded and photographed. Special-status species and habitat features, such as vegetation communities or ephemeral channels, were also recorded and photographed if observed.
Coordinates for important biological resource elements and direct observations of special-status species were recorded using a handheld geographic positioning system unit. If observed, San Joaquin kit fox (SJKF) dens were classified as defined by the USFWS Standardized Recommendations for Protection of the Endangered San Joaquin Kit Fox Prior to or During Ground Disturbance (2011). All plant taxa encountered were identified to the extent possible given the diagnostic features present. Identifications Biological Resource Evaluation
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3 were made using keys contained in The Jepson Manual: Vascular Plants of California and online updates containing revisions to taxonomic treatments (Baldwin et al. 2012; Jepson Flora Project 2015).
RESULTS
This section summarizes the results of the field study conducted on the project site and evaluates those results for the known or potential for occurrence of special-status species based on the literature review and database queries and pursuant to statutory regulation. Discussions are provided describing the existing habitat conditions including vegetation communities, land cover and current use; soils; specialstatus biological resources potentially occurring in the vicinity of the project site; the potential for jurisdictional resources including designated critical habitat and riparian/wetland/water resource features; the potential for wildlife migration corridors and nursery sites; and regional and local policy.
VEGETATION COMMUNITIES AND LAND COVER
The project site is located at the west edge of urban development of Metropolitan Bakersfield. Before conversion to farmland, the original vegetive communities of the project site were Non-native Grassland (Holland 42200) and Valley Saltbush Scrub (Holland 36220). No undisturbed, native, or recovering habitat is present on the project site, adjacent parcels, or general vicinity of the project. The project includes single family residences with vacant land. The project is surrounded by mixed use residential and commercial development with scattered oil production The project and vicinity were historically farmed for decades. Historical aerial imagery going back to 1985 shows residential development of the project with much of the surrounding land under row crops. Aerial imagery shows that by 2003, commercial development had begun along Rosedale Highway in the immediate vicinity of the project. No undisturbed, native, or recovering habitat is present on the project site or adjacent parcels. The potential for any native herbaceous species is extremely low due to ongoing disturbance. The project site and margins are dominated by ruderal/invasive plant species.
SOILS
Map Unit
Symbol
Map Unit Name Description
127 Granoso sandy loam, 0 to 2
percent slopes, overwash
Somewhat excessively drained soil formed from alluvium
derived from mixed rock sources
174 Kimberlina fine sandy loam, 0
to 2 percent slopes.
Well drained fan remnant formed from igneous and
sedimentary rock
Source: NRCS 2025
BIOLOGICAL RESOURCES
The literature review and database queries yielded 21 special-status plant species as potentially occurring within the vicinity of the project site. Thirty-four animal species were identified as potentially occurring in the region of the project site. No evidence of any listed animal species was observed during the field study. No evidence of any locally rare plant or animal species was observed. No evidence of otherwise special-status plant or animal species, or animal species sign was observed during the field study.
No focused, protocol-level surveys were conducted for the preparation of this report. The field study was conducted outside of the blooming period for many of the special-status plant species potentially occurring in the vicinity of the project. The evaluation of special-status species that were found during the literature review with a potential to occur in the region are included in Appendix B.
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4 Special-Status Plant Species
The federal and state database queries yielded 21 special-status plant species as potentially occurring within the vicinity of the project site. A query of the California Native Plant Society (CNPS) database was made for the nine-quadrangles surrounding the project. A USGS nine-quadrangle query additionally includes a search area beyond a standard 10-mile radius. Plant species meeting the criteria for Special Status Plants as defined in Protocols for Surveying and Evaluating Impacts to Special Status Native Plant Populations and Sensitive Natural Communities (CDFW 2018) were evaluated under CEQA Section 15380.
Special-status plant species considered in this evaluation include all plant species that meet one or more of the following criteria:
Listed or proposed for listing as threatened or endangered under ESA or candidates for possible future listing as threatened or endangered under the ESA (50 CFR §17.12). Listed or candidates for listing by the State of California as threatened or endangered under CESA (Fish and Game Code §2050 et seq.). A species, subspecies, or variety of plant is endangered when the prospects of its survival and reproduction in the wild are in immediate jeopardy from one or more causes, including loss of habitat, change in habitat, over-exploitation, predation, competition, disease, or other factors (Fish and Game Code §2062). A plant is threatened when it is likely to become endangered in the foreseeable future in the absence of special protection and management measures (Fish and Game Code §2067). Listed as rare under the California Native Plant Protection Act (Fish and Game Code §1900 et seq.). A plant is rare when, although not presently threatened with extinction, the species, subspecies, or variety is found in such small numbers throughout its range that it may be endangered if its environment worsens (Fish and Game Code §1901). Meet the definition of rare or endangered under CEQA §15380(b) and (d). Species that may meet the definition of rare or endangered include the following:
o Species considered by the California Native Plant Society (CNPS) to be “rare, threatened or endangered in California” (Lists 1A, 1B and 2);
o Species that may warrant consideration on the basis of local significance or recent biological information.
o Some species included on the California Natural Diversity Database’s (CNDDB) Special Plants, Bryophytes, and Lichens List (California Department of Fish and Game 2008). Considered a locally significant species, that is, a species that is not rare from a statewide perspective but is rare or uncommon in a local context such as within a county or region (CEQA §15125 (c)) or is so designated in local or regional plans, policies, or ordinances (CEQA Guidelines, Appendix G). Examples include a species at the outer limits of its known range or a species occurring on an uncommon soil type.
Some CRPR 4 taxa may meet the Section 15380 definition of an endangered, rare, or threatened species, and in the definition of CRPR 4, CNPS and CDFW suggest additional reasons for including CRPR 4 taxa in a CEQA analysis. These reasons include Regionally Rare Taxa. Considered locally significant plants, that is, plants that are not rare from a statewide perspective but are rare or uncommon in a local context such as within a county or region (CEQA Guidelines, § 15125, subd. (c)), or as designated in local or regional plans, policies, or ordinances (CEQA Guidelines, Appendix G). “Locally rare” has not been generally defined, but in counties where a “locally rare” policy exists, it applies to taxa with only five to 10 known occurrences in that county. The CNDDB, IPaC, and CNPS lists were crossreferenced for consistency.
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5 Precipitation has been well above average to date, resulting in a good year for annual plant species observations. Of the 21 special-status plant species returned during database queries for the project vicinity, 5 species are either federally- or state-listed as threatened or endangered. Although CEQA requires consideration for impacts to locally significant plant species, no mitigation is legally required to compensate for impacts to non-listed plant species. No listed, or otherwise special-status plant species was observed during the fieldwork conducted for the preparation of this report. No listed, or otherwise special-status plant species, has been recorded as occurring within the project site.
Special-Status Animal Species
The federal and state database queries yielded 34 special-status animal species as potentially occurring within the vicinity of the project site. Of these, 16 animal species have federal-, and/or state-listing and are afforded protection under federal or state law. Special-status animal species considered in this evaluation include those that may occur in the project vicinity that have statutory protections. This includes federal- and state-listed (rare, threatened, or endangered; fully protected) species and candidates for listing under the respective endangered species acts. Species that are of special concern to the CDFW or the USFWS are included in this evaluation. Special-status bird species that are afforded protection under the MBTA which may nest on or within an approximate 10-mile (16-kilometer) radius of the project site are also evaluated. No evidence of any listed animal species was observed during the field study. No evidence of otherwise special-status animal species, or animal species sign was observed during the field study.
Designated Critical Habitat
The USFWS IPaC report and USFWS Designated Critical Habitat Mapper lists no Designated Critical Habitat (USFWS 2025). Designated Critical Habitats closest to the project site include California condor (Gymnogyps californianus) approximately 22-miles south/southwest and Buena Vista Lake shrew (Sorex ornatus relictus) approximately 11-miles west of the project site. No suitable habitat for either species exists on the project site.
Jurisdictional Water Resource Features
Section 404 of the Federal Clean Water Act (CWA) regulates discharge of dredged and fill material into Waters of the United States. Wetlands are included under this jurisdiction. Proposed activities that may result in discharge of material into Waters of the U.S. require a permit review process by the U.S. Army Corps of Engineers as set forth under CWA section 404(b)(1). Fish and Game Code section 1602 requires any person, state or local governmental agency, or public utility to notify CDFW before beginning any activity that will substantially modify a river, stream, or lake.
A search of the USFWS National Wetlands Inventory resulted in no riparian, wetlands, or other jurisdictional water features mapped on the project site (USFWS 2025). These results are consistent with the observed conditions within the survey area.
Special-Status Natural Communities
No special-status vegetation communities on the project site were identified by the USFWS IPaC query, the CNDDB, or the CNPS Inventory (USFWS 2025, CDFW 2025, CNPS 2025). These results are consistent with the observed conditions within the survey area.
Wildlife Migration Corridors and Nursery Sites
Wildlife corridors can be defined as connections between wildlife blocks that meet specific habitat needs for species movement generally during migratory periods but seasonally as well. Wildlife corridors generally contain habitat dissimilar to the surrounding vicinity and include examples such as riparian areas along rivers and streams, washes, canyons, or otherwise undisturbed areas within urbanization.
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6 Corridor width requirements can vary based on the needs of the species utilizing them. Development of the project would not impact wildlife migration corridors or nursery sites.
Regional and Local Policies
The proposed, modified project will not conflict with existing or adopted Habitat Conservation Plans, Natural Community Conservation Plans, local or regional conservation plans, or local ordinances protecting biological resources.
IMPACT ANALYSIS AND RECOMMENDED MITIGATION MEASURES
CEQA Appendix G thresholds have been used to evaluate potential impacts to the biological resources from the proposed project. Appendix G provides an analysis of the impacts of the proposed project following the standards of CEQA and provides recommendations that, when implemented, would reduce impacts to less-than-significant levels. It is important to note that potential take of any federal- or statelisted species from project activities would require contacting the appropriate wildlife agency (the USFWS and/or the CDFW).
The California Department of Fish and Wildlife (CDFW) and United States Fish and Wildlife Service (USFWS) have not been contacted regarding the preparation of this report. Appendix B, Special-Status Plant and Animal Evaluations, satisfy the requirements for an initial determination of potential impacts under the CEQA Appendix G thresholds. If CEQA threshold determinations warrant, further consultation may be required with CDFW and USFWS. If additional consultation with the agencies results in the need for Application for a California Incidental Take Permit, Cal. Code Regs., tit. 14, § 783.2 outlines requirements for detailed species-specific take analysis, proposed measures to minimize and fully mitigate impacts, compliance monitoring, and funding. A detailed description satisfying Cal. Code Regs., tit. 14, § 783.2 is not required to meet the CEQA Appendix G thresholds.
The project would create a significant impact to biological resources, based on the specifications in Appendix G of the CEQA Guidelines, if the following were to occur:
1. Have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service;
2. Have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, and regulations or by the California Department of Fish and Game or U.S. Fish and Wildlife Service;
3. Have a substantial adverse effect on federally protected wetlands as defined by section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means;
4. Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites;
5. Conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance;
6. Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan.
The following analysis discusses potential impacts associated with the development of the project and provides recommendations where appropriate to further reduce potential impacts.
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7 1. Would the project have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special-status species in local or regional plans, policies, or regulations, by the CDFW, or the USFWS? Direct and indirect impacts, in the form of “incidental take” of a threatened, endangered, or otherwise protected species, are not expected as a result of the development of the proposed project.
Implementation of standard measures for the protection of biological resources are recommended to avoid and minimize potential impact to general wildlife. These measures include, but may not be limited to:
A biological resource pre-activity survey conducted by a qualified biologist no more than 30- days before the start of construction activities,
Biological resource monitoring during each initial phase of ground disturbance, Compliance reporting provided to the required oversight agencies for all biological resource field surveys, monitoring, and additional tasks as warranted.
If known or natal SJKF dens are identified at any time during construction, protocols enumerated in the USFWS Standardized Recommendations for Protection of the Endangered San Joaquin Kit Fox Prior to or During Ground Disturbance (2011) should be implemented, and the appropriate agencies contacted for guidance.
The project is within the historic range of Tipton kangaroo rat. The project was not included in the southwest focus area for the species in the previous habitat conservation plan. The most recent habitat suitability modeling (Cypher 2021) does not include the project in any of the four tiers enumerated for suitability. Trapping would be required to confirm small mammal species occupying the project.
2. Would the project have a substantial adverse effect on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, and regulations, or by the CDFW or the USFWS?
No riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the California Department of Fish and Wildlife or United States Fish and Wildlife Service exists on the project site. No adverse effect will occur as a result of the development of the proposed project and no mitigation measures are recommended.
3. Would the project have a substantial adverse effect on federally protected wetlands as defined by Section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? No features, identified in wetland categories, appear on the USFWS National Wetlands Inventory mapping (USFWS 2025) on the proposed, modified project site. No federally protected wetlands as defined by Section 404 of the Clean Water Act were identified during the field study conducted for the preparation of this report. No substantial adverse effect will occur as a result of the development of the project. No mitigation measures are recommended.
4. Would the project interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? No migratory wildlife corridors were identified during the literature search or field study. The project will not interfere substantially with the movement of any native fish of wildlife species or with established native resident or migratory wildlife corridors or impede the use of native wildlife nursery sites. The following recommendations are provided for the general protection of bird species that may occur on the project site or vicinity in compliance with the MBTA:
If ground-disturbing activities are planned during the nesting season for migratory birds that may nest on or near the site (generally February 1 through August 31), nesting bird surveys are recommended prior to Biological Resource Evaluation
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8 the commencement of ground disturbance for project activities. If nesting birds are present, no new construction or ground disturbance should occur within an appropriate avoidance area for that species until young have fledged, unless otherwise approved and monitored by a qualified onsite biologist.
Appropriate avoidance should be determined by a qualified biologist. In general, minimum avoidance zones for active nests should be implemented as follows: 1) ground or low-shrub nesting non-raptors – 300 feet (91 meters); 2) burrowing owl – as appropriate based on nest location, existing surrounding activity, and evaluation of owl behavior. Coordination with CDFW may be warranted. 3) Sensitive raptors (e.g., prairie falcon, golden eagle) – 0.5 miles (0.8 kilometers); 4) other raptors – 500 feet (152 meters).
5. Would the project conflict with any local policies or ordinances protecting biological resources, such as a tree preservation policy or ordinance? There are no biological resources on the site which are protected by local policies. Impacts from conflicts with local policies will not occur. No additional mitigation measures are recommended.
6. Conflict with the provisions of an adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan.
The project does not conflict with any Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan. No additional mitigation measures are recommended.
RECOMMENDED MITIGATION MEASURES
The following Avoidance and Minimization Measures (AMM) represent the authors professional opinion regarding reducing the probability of take occurring during project activities. The following AMMs are generally regarded as best management practices during construction activities in the southern San Joaquin valley, however they are not a substitute for procuring the appropriate state and federal permits to allow for take of special-status species during project activities and do not provide coverage should take occur during project activities. Communication with state and federal agencies regarding proposed AMMS is recommended prior to initial ground disturbance to fully comply with FESA, CESA, and CEQA.
These measures include, but may not be limited to:
A biological resource pre-activity survey conducted by a qualified biologist no more than 30- days before the start of construction activities,
Biological resource monitoring during each initial phase of ground disturbance, Compliance reporting provided to the required oversight agencies for all biological resource field surveys, monitoring, and additional tasks as warranted, A Worker Environmental Awareness Program outlining special-status species that may access, use or otherwise transverse the project area will be implemented, If known or natal SJKF dens are identified at any time during construction, protocols enumerated in the USFWS Standardized Recommendations for Protection of the Endangered San Joaquin Kit Fox Prior to or During Ground Disturbance (2011) should be implemented, and the appropriate agencies contacted for guidance. Vertical sided trenching deeper than 2-feet should include escape ramps at no more than a 1:1 ratio every 100 feet,
Vertical sided holes that are not capable of being ramped should be covered or otherwise secured to the greatest extent practicable
Pipes, conduit and similar material 3 inches or greater should be capped to prevent wildlife from becoming inadvertently trapped in the piping
The following recommendations are provided for the general protection of bird species that may occur on the project site or vicinity in compliance with the MBTA:
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9 If ground-disturbing activities are planned during the nesting season for migratory birds that may nest on or near the site (generally February 1 through August 31), nesting bird surveys are recommended prior to the commencement of ground disturbance for project activities. If nesting birds are present, no new construction or ground disturbance should occur within an appropriate avoidance area for that species until young have fledged, unless otherwise approved and monitored by a qualified onsite biologist.
Appropriate avoidance should be determined by a qualified biologist. In general, minimum avoidance zones for active nests should be implemented as follows:
1) Ground or low-shrub nesting non-raptors – 300 feet (91 meters), 2) Burrowing owl – as appropriate based on nest location, existing surrounding activity, and evaluation of owl behavior. Coordination with CDFW may be warranted, 3) Sensitive raptors (e.g., prairie falcon, golden eagle) – 0.5 miles (0.8 kilometers), 4) Other raptors – 500 feet (152 meters).
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10 REFERENCES
Baldwin, B. G., Goldman, D. H., Keil, D. J., Patterson, R., Rosatti, T. J., & Wilken, D. H. (Eds.). (2012).
The Jepson manual: Vascular plants of California (2nd ed.). Berkeley, CA: University of California Press. 1568 pp.
CDFG. (2009). Protocols for surveying and evaluating impacts to special status native plant populations and natural communities. Sacramento, CA: Author. 7 pp.
CDFG. (2012). Staff report on burrowing owl mitigation. Sacramento, CA: Author.
CNDDB. (2025). Occurrence for U.S. Geologic Survey 7.5 minute quadrangles. Sacramento, CA: CDFW California Endangered Species Act of 1970, C.F.G.C § 2050 et seq. (2025).
California Environmental Quality Act of 1970, 13 P.R.C. § 21000 et seq. (2025).
California Environmental Quality Act of 1970 Guidelines, 14 C.C.R. § 15000 et seq. (2025).
California Native Plant Society (CNPS). (2025). Inventory of rare and endangered plants (Online edition, v8-01a) 7.5 minute quadrangles and corresponding plant species accounts. Sacramento, CA: Author.
California Native Plant Protection Act of 1977, C.F.G.C § 1904 et seq. (2025).
Clean Water Act of 1972, 33 U.S.C. § 1251 et seq. (2014).
Cypher, B., Phillips, S.E., Westall, T., Tennant, E.N., Saslaw, L., Kelly, E., Van Horn Job, C. (2021).
Conservation of endangered Tipton kangaroo rat (Dipodomys nitratoides nitratoides): status surveys, habitat suitability, and conservation recommendations. California Fish and Wildlife Special CESA Issue:382-397.
Dunn, J. L., & Alderfer, J., (Eds.). (2008). Field guide to the birds of western North America. Washington, DC: National Geographic Society. 447 pp.
Ehrlich, P. R., Dobkin, D. S., & Wheye, D. (1988). The birder’s handbook: A field guide to the natural history of North American birds. New York, NY: Simon and Schuster, Inc. 785 pp.
Federal Endangered Species Act of 1973, 16 U.S.C. § 1531 et seq. (2025).
Harris, J. H., & Stearns, D. M. (1991). Population density, census methods, habitat relationships, and home range of the San Joaquin antelope squirrel, 1988–89. California Department of Fish and Game, Nongame Bird and Mammal Section, Report 91-02. Oakland, CA: CDFG. Retrieved from http://nrm.dfg.ca.gov/FileHandler.ashx?DocumentID=2953
Jennings, M. R., Hayes, M. P., & Metro Washington Park Zoo. (1994). Amphibian and reptile species of special concern in California (Final report to the California Department of Fish and Game, Inland Fisheries Division, Contract No. 8023). Rancho Cordova, CA: CDFG. 255 pp.
Jepson Flora project (Eds.). (2015). Jepson eFlora. Retrieved from http://ucjeps.berkeley.edu/IJM.html Luce, B. (2005). Eumops perotis: Western mastiff bat. In C. Chambers & M. Herder, (Eds.), Species accounts. Portland, OR: Western Bat Working Group. 5 pp. Retrieved from http://www.wbwg.org/speciesinfo/species_accounts/molossidae/eupe.pdf Biological Resource Evaluation
APN 540-010-19
November 2025
11 Migratory Bird Treaty Act of 1918, 16 U.S.C. § 703 et seq. (2025).
Nafis, G. (2000–2021a). North American legless lizards - Anniella. A Guide to the Amphibians and Reptiles of California. Retrieved from http://www.californiaherps.com/lizards/pages/a.pulchra.html Nafis, G. (2000–2021b). San Joaquin coachwhip – Coluber flagellum ruddocki. A Guide to the Amphibians and Reptiles of California. Retrieved from
http://www.californiaherps.com/snakes/pages/c.f.ruddocki.html Nafis, G. (2000–2021c). Blainville’s horned lizard – Phrynosoma blainvillii. A Guide to the Amphibians and Reptiles of California. Retrieved from http://www.californiaherps.com/lizards/pages/p.blainvillii.html Native Fish and Wildlife Endangered Species, 32 Fed. Reg. 4001 (Mar. 11, 1967). Retrieved from http://ecos.fws.gov/docs/federal_register/fr18.pdf
Papenfuss, T. J., Parham, J. F. (2013). Four new species of California legless lizards (Anniella). Breviora 536, 1–17. Retrieved from
http://mczbase.mcz.harvard.edu/specimen_images/publications/Breviora_536.pdf Porter-Cologne Water Quality Control Act, C.W.A. § Section 13000 et seq. (2025).
Reid, F. A. (2006). Mammals of North America (Peterson field guide). Boston, MA: Houghton Mifflin Company. 579 pp.
Sherwin, R. (2005). Antrozous pallidus: Pallid bat. In D. A. Rambaldini, (Eds.). Species accounts.
Portland, OR: Western Bat Working Group. 5 pp. Retrieved from http://www.wbwg.org/speciesinfo/species_accounts/vespertilonidae/anpa.pdf Shuford, W. D., Gardali, T., (with Comrack, L.A.). (Eds.). (2008). California bird species of special concern: a ranked assessment of species, subspecies, and distinct populations of birds of immediate conservation concern in California. Sacramento, CA: CDFG.
Stebbins, R. C. (1985). A field guide to western reptiles and amphibians (Peterson field guide), (2nd ed.).
Boston, MA: Houghton Mifflin Company. 336 pp.
Stebbins, R. C. (2003). A field guide to western reptiles and amphibians (Peterson field guide), (3rd ed.).
Boston, MA: Houghton Mifflin Company. 533 pp.
Twisselmann, E. C. (1967). A flora of Kern County, California. The Wasmann Journal of Biology, 25, 1– 395.
Uptain, C. E. (1989). Survey for Tipton kangaroo rats (Dipodomys nitratoides nitratoides) on the proposed Delano prison site, Kern County, California (Prepared for the California Department of Corrections).
Sacramento, CA: 11 pp.
U.S. Fish and Wildlife Service (USFWS). (1996). California condor recovery plan, third revision. Portland, OR: Author. 62 pp.
USFWS. (1998). Recovery plan for upland species of the San Joaquin Valley, California. Portland, OR:
Author. Retrieved from http://ecos.fws.gov/docs/recovery_plan/980930a.pdf USFWS. (2011). U.S. Fish and Wildlife Service standardized recommendations for protection of the endangered San Joaquin kit fox prior to or during ground disturbance. Sacramento, CA: Author. 9 pp.
Retrieved from http://www.fws.gov/sacramento/es/Survey-ProtocolsGuidelines/Documents/kitfox_standard_rec_2011.pdf Biological Resource Evaluation
APN 540-010-19
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12 USFWS. (2013). California condor recovery program population size and distribution, December 31, 2013 overview page. Retrieved from
http://www.fws.gov/uploadedFiles/Region_8/NWRS/Zone_1/Hopper_Mountain_Complex/Hopper_Mounta in/Sections/News/News_Items/PDFs/2013-12-31.pdf
USFWS. (2025a). Federal endangered and threatened species that may occur in or may be affected by project in the counties and/or USGS 7 ½ minute quads you requested: quadrangle [November]. Author.
Retrieved from http://www.fws.gov/sacramento/es_species/Lists/es_species_lists-form.cfm USFWS. (2025b). National Wetlands Inventory Website [February]. Washington, D.C.: Author. Retrieved from http://www.fws.gov/wetlands/
Williams, D. F. (1980). Distribution and population status of the San Joaquin antelope squirrel and giant kangaroo rat. (Nongame Wildlife Investigation Final Report E-W-4). Sacramento, CA: CDFG. 48 pp.
Williams, D. F. (1986). Mammalian species of special concern in California (Prepared for the State of California, The Resources Agency Department of Fish and Game). Turlock, CA: CSUS. 112 pp. Retrieved from http://esrp.csustan.edu/resources/publications/pdf/mammalian_scc_ca_esrp5.pdf Zeiner, D. C., Laudenslayer, W. F., Jr., Mayer, K. E., & White, M., (Eds.). (1990a). California’s wildlife volume II birds (California Statewide Wildlife Habitat Relationships System). Sacramento, CA: CDFG.
Zeiner, D. C., Laudenslayer, W. F., Jr., Mayer, K. E., & White, M., (Eds.). (1990b). California’s wildlife volume III mammals (California Statewide Wildlife Habitat Relationships System). Sacramento, CA:
CDFG.
APPENDIX A
PROJECT VICINTY AND SITE
APPENDIX A
PROJECT VICINTY AND SITE
Biological Resource Evaluation
APN 540-010-19
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Bakersfield 4 OF a4
is} ("4 = o. = (3
ie
Mecurcns owe Oo 0.05, O1 ———— Miles
it
Figure A-1. Aerial photograph of the project and vicinity Biological Resource Evaluation
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Figure A-1. Aerial photograph of the project and vicinity Biological Resource Evaluation
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Figure A-2 Soil map of the project site (USDA, Natural Resources Conservation Service 2025).
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Figure A-3. Photograph taken near the southeastern corner of the project facing north (November 14, 2025).
Figure A-4. Photograph taken near the southeastern corner of the project facing west (November 14, 2025).
Biological Resource Evaluation
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17 Figure A-5. Photograph taken near the northwestern corner of the project facing east (November 14, 2025).
Figure A-6. Photograph taken near the northwestern corner of the project facing south (November 14, 2025).
APPENDIX B
SPECIAL-STATUS PLANT AND ANIMAL EVALUATION
APPENDIX B
SPECIAL-STATUS PLANT AND ANIMAL EVALUATION
Biological Resource Evaluation
APN 540-010-19
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Table B-1: Special-status Plants That May Occur in the Vicinity of the Project.
Scientific Name
Common Name
Status
Fed/State/CNPS Description Blooming Period
Field Study
Results/Potential for
Occurrence
Astragalus hornii var.
hornii
Horn’s milk vetch
S/-/1B.1 Annual herb in the Fabaceae family found in meadows and seeps and on playas and lake margins on alkaline soils
between 197 and 2,790 feet (60–850 meters) in elevation.
Known from occurrences in the Southern San Joaquin
Valley, the Tehachapi Mountains and the Western
Transverse Ranges in Kern, Los Angeles, and San
Bernardino Counties.
May to October Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
Thirteen records were found
in the vicinity. The nearest
record was 2.0 miles away,
recorded in 1964.
Atriplex cordulata var.
cordulata
Heartscale
S/-/1B.2 Herbaceous annual in the Chenopodiaceae family found in chenopod scrub, meadows and weeps, and valley and
foothill grasslands on sandy, saline or alkaline soils below 1,837 feet (560 meters) in elevation. Known to occur in the Great Central Valley from Kern County north to Southern Butte County.
April to October Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
One record was found in the
vicinity. It was 8.9 miles
away, recorded in 1983, and
possibly extirpated.
Atriplex coronata var.
vallicola
Lost Hills crownscale
S/-/1B.2 Herbaceous annual in the Chenopodiaceae family found in chenopod scrub, valley and foothill grasslands, and vernal pool habitats on alkaline soils between 165 and 2,085 feet (50–635 meters) in elevation. Known to occur in Fresno, Kern, Kings, Merced, Monterey, San Benito, San Luis
Obispo, and Tulare Counties.
April to September Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
One record was found in the
vicinity. It was 8.8 miles
away and recorded in 1995.
Atriplex tularensis
Bakersfield smallscale
-/E/1A Annual herb in the Chenopodiaceae family found in chenopod scrub habitat between 295 and 655 feet (90–200 meters) in elevation. Known to occur in the Kern County.
June to October Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
Two records were found in
the vicinity at 5.6 and 8.7
miles away and are
presumed extirpated.
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20 Scientific Name
Common Name
Status
Fed/State/CNPS Description Blooming Period
Field Study
Results/Potential for
Occurrence
Calochortus striatus
Alkali mariposa-lily
S/-/1B.2 Bulbiferous perennial herb in the Liliaceae family found in chaparral, chenopod scrub, meadows and seeps, and
Mojavean desert scrub in alkaline and mesic soils between 230 and 5235 feet (70–1,595 meters). Known to occur in
the Inyo, Kern, Los Angeles, San Bernardino, and Tulare Counties.
April to June Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
Two records were found in
the vicinity. The nearest
record found was 5.5 miles
away and recorded in 2006.
Caulanthus californicus
California jewelflower
E/E/1B.1 Annual herb in the Brassicaceae family found in chenopod scrub, pinyon and juniper woodland, and valley and foothill grassland habitats on sandy soils between 200 and 3,280 feet (61 – 1000) in elevation. Known to occur in Fresno, Kern, San Luis Obispo, and Santa Barbara Counties.
Presumed extirpated from Kings and Tulare Counties.
February to May Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
One record was found in the
vicinity. It was 6.1 miles
away but was extirpated.
Chloropyron molle ssp.
hispidum
Hispid salty bird’s-beak
S/-/1B.1 Hemiparasitic annual herb in the Orobanchaceae family found in meadows and sweeps, playas, and valley and
foothill grasslands on alkaline soils below 510 feet (155 meters) in elevation. Known to occur in Alameda, Kern,
Merced, Placer, and Solano Counties.
June to September Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
Two records were found in
the vicinity. The nearest was
6.5 miles away and recorded
in 1927.
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APN 540-010-19
November 2025
21 Scientific Name
Common Name
Status
Fed/State/CNPS Description Blooming Period
Field Study
Results/Potential for
Occurrence
Delphinium recurvatum
Recurved larkspur
S/-/1B.2 Perennial herb in the Ranunculaceae family found in chenopod scrub, cismontane woodland, and valley and
foothill grassland habitats below 2,590 feet (790 meters) in elevation. Known to occur in Kern and Tulare Counties.
March to June Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
Six records were found in
the vicinity. The nearest was
3.8 miles away, recorded in
1935, and was possibly
extirpated. The next closest
was 4.6 miles away and
recorded in 1992.
Diplacus pictus
Calico monkeyflower
S/-/1B.2 Annual herb in the Phrymaceae family found in broadleafed upland forests and cismontane woodlands in disturbed and granitic soils between 330 and 4,690 feet (100 – 1,430
meters) in elevation. Known to occur in Kern and Tulare Counties.
March to May Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
No records were found in
the vicinity. This species is
known to occur in the quad
to the northeast.
Eremalche parryi ssp.
kernensis
Kern mallow
E/-/1B.2 Annual herb in the Malvaceae family found in chenopod scrub, pinyon and juniper woodland, and valley and foothill grassland habitats in clay, dry, openings, and sandy soils often at the edge of balds between 230 and 4,230 feet (70 – 1,290 meters) in elevation. Known to occur in Kern,
Kings, San Luis Obispo, Santa Barbara, Tulare, and
Ventura Counties.
January to May Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
Seven records were found in
the vicinity. The nearest
record was 4.9 miles away
and recorded in 2020.
Eschscholzia lemmonii
ssp. kernensis
Tejon poppy
S/-/1B.1 Annual herb in the Papaveraceae family found in chenopod scrub and valley and foothill grasslands between 525 and 3,280 feet (160-1,000 meters). Known to occur in Kern and San Luis Obispo Counties.
(February) March to May Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
No records were found in
the vicinity. This species is
Biological Resource Evaluation
APN 540-010-19
November 2025
22 Scientific Name
Common Name
Status
Fed/State/CNPS Description Blooming Period
Field Study
Results/Potential for
Occurrence
known to occur in the quad
to the northeast.
Imperata brevifolia
California satintail
-/-/2B.1 Perennial, rhizomatous herb in the Poaceae family found in chaparral, coastal sage scrub, meadow and seeps,
Mojavean desert scrub, and riparian scrub habitats on
mesic and alkaline soils below 3,985 feet (1,215 meters).
Known to occur in Butte, Lake, Fresno, Tulare, Inyo, Kern, Santa Barbara, Ventura, San Bernadino, Orange,
Riverside, San Diego and Imperial Counties.
September to May Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
One record was found in the
vicinity. It was 6.5 miles
away and recorded in 1896.
Lasthenia glabrata ssp.
coulteri
Coulter’s goldfields
S/-/1B.1 Annual herb in the Asteraceae family found in vernal pools, marshes and swamps, playas, and saline places at
elevations below 4,005 feet (1,220 meters). Known to occur in Colusa, Kern, Los Angeles, San Bernardino, San Diego, San Luis Obispo, Santa Barbara, Solano, Tehama, Tulare, Ventura, and Yolo Counties.
February to June Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
One record was found in the
vicinity. It was 8.2 miles
away and recorded in 1963.
Layia leucopappa
Comanche Point layia
S/-/1B.1 Annual herb in the Asteraceae family found in chenopod scrub and valley and foothill grassland between 330 and 1,150 feet (100-350 meters) in elevation. Known to occur in Kern County.
March to April Not Observed/Not
Expected. Decades of inand
recorded intensive farming
has resulted in vegetation
limited to invasive/ruderal
species.
No records were found in
the vicinity. This species is
known to occur in the quads
to the east and northeast.
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November 2025
23 Scientific Name
Common Name
Status
Fed/State/CNPS Description Blooming Period
Field Study
Results/Potential for
Occurrence
Monolopia congdonii
San Joaquin woollythreads
E/-/1B.2 Annual herb in the Asteraceae family found in chenopod scrub and valley and foothill grassland habitats on sandy soils between 195 and 2,625 feet (60 – 800 meters) in
elevation. Known to occur in Fresno, Kern, Kings, San
Benito, San Luis Obispo, Santa Barbara, and Tulare
Counties.
February to May Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
Four records were found in
the vicinity. The nearest was
6.1 miles away and was
possibly extirpated. The next
closest was 6.2 miles away
and was recorded in 2013.
Navarretia setiloba
Piute Mountains
navarretia
S/-/1B.1 Annual herb in the Polemoniaceae family found in cismontane woodland, pinyon and juniper woodlands, and
valley and foothill grasslands in clay, gravelly, and loam soils between 935 and 6,890 feet (285–2,100 meters) in
elevation. Known to occur in Kern, Los Angeles, and Tulare Counties.
April to July Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
No records were found in
the vicinity. This species is
known to occur in the quad
to the east.
Opuntia basilaris var.
treleasei
Bakersfield cactus
E/E/1B.1 Perennial stem succulent in the Cactaceae family found in chenopod scrub, cismontane woodland, and valley and
foothill grasslands between 330 and 4,755 feet (100–1450 meters) in elevation. Known to occur in the Southeast San Joaquin Valley and Southern Sierra Nevada Foothills in
Kern County.
April to May Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
One record was found in the
vicinity. It was 7.6 miles
away and recorded in 2019.
Puccinellia simplex
California alkali grass
S/-/1B.2 Annual herb in the Poaceae family found in chenopod scrub, meadows and seeps, valley and foothill grasslands, and vernal pools in alkaline, vernally-mesic sinks, flats, and lake margins between 5 to 3,050 feet (2 – 930 meters) in elevation. Known to occur in Alameda, Butte, Colusa,
Contra Costa, Fresno, Glenn, Kern, Lake, Los Angeles,
Madera, Merced, Napa, San Bernardino, San Luis Obispo,
Santa Clara, Santa Cruz, Solano, Stanislaus, Tulare, and Yolo Counties. Presumed extirpated from Kings County.
March to May Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
No records were found in
the vicinity. This species is
known to occur in the quad
to the southeast.
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November 2025
24 Scientific Name
Common Name
Status
Fed/State/CNPS Description Blooming Period
Field Study
Results/Potential for
Occurrence
Stylocline citroleum
Oil neststraw
S/-/1B.1 Annual herb in the Asteraceae family found in chenopod scrub and valley and foothill grasslands in clay soils
between 35 and 4,790 feet (10–1,460 meters) in elevation.
Known to occur in Kern County. Presumed extirpated from San Diego County.
March to April Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
No records were found in
the vicinity. This species is
known to occur in the quad
to the northeast.
Stylocline masonii
Mason’s neststraw
S/-/1B.1 Annual herb in the Asteraceae family found in chenopod scrub and valley and foothill grasslands on sandy soils between 330 and 3,935 feet (100–1,200 meters) in
elevation. Known from locations in Kern, Los Angeles,
Monterey, and San Luis Obispo Counties.
March to May Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
One record was found in the
vicinity. It was 7.6 miles
away and recorded in 2019.
Tortula californica
California screw-moss
S/-/1B.2 Moss in the Pottiaceae family found in chenopod scrub and valley and foothill grasslands in sandy soils between 35 and 4,790 feet (10–1,460 meters) in elevation. Known from
locations in Kern, Los Angeles, Modoc, Monterey,
Riverside, San Diego, Santa Barbara, and Ventura
Counties.
N/A Not Observed/Not
Expected. Decades of
intensive farming has
resulted in vegetation limited
to invasive/ruderal species.
No records were found in
the vicinity. This species is
known to occur in the quad
to the northeast.
STATUS: Federal and State Listing Code
D Delisted
E Federally or State-listed Endangered
T Federally or State-listed Threatened
CNPS
1A Plants presumed extirpated in California, and either rare or extinct elsewhere 1B.1 Plants considered rare, threatened, or endangered in California and elsewhere; seriously threatened in California 1B.2 Plants considered rare, threatened, or endangered in California and elsewhere; fairly threatened in California 2B.1 Plants considered rare, threatened, or endangered in California, but more common elsewhere; seriously threatened in California
4.2 Plants of limited distribution in California; fairly threatened in California Biological Resource Evaluation
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November 2025
25 Table B-2: Special-status Animals That May Occur in the Vicinity of the Project.
Scientific Name
Common Name
Status
Federal/State General Habitat Survey Results/Regional or Nearest Occurrence* Invertebrates
Bombus crotchii
Crotch’s bumble bee
-/C Occurs in grasslands and shrublands in the
Mediterranean region, Pacific coast, western desert,
and adjacent foothills throughout California’s southwest region. Food plant genera include but is not limited to Antirrhinum, Clarkia, Eriogonum. and Phacelia.
Not Observed/Not Expected. No
suitable habitat present and no typical
food plant genera observed.
Seven records were found in the vicinity.
The nearest was 3.5 miles away and
recorded in 2020.
Branchinect lynchi
Vernal pool fairy shrimp
T/- Found in vernal pools throughout California. Exist as cysts during the dry season and reproduce when pools
are filled with water again.
Not Present. No suitable habitat present.
No records were found in the vicinity.
Danaus plexippus
Monarch butterfly
PT/- Occur for migration between San Diego and British
Colombia. Asclepias spp. are used for egg laying
throughout the range and are a crucial part of their life cycle.
Not Observed/Not Expected. No known
records in the vicinity of the project. No
Asclepias spp. observed on the project.
Two records were found in the vicinity.
The nearest was 9.6 miles away and
recorded in 1985.
Amphibians
Spea hammondii
Western spadefoot toad
PT/ CSC Central valley and adjacent foothills, Coast Ranges from Point Conception south to the Mexico border;
valley-foothill grasslands and valley-foothill hardwood, shallow temporary pools used for breeding, below
4,472 feet (1,363 meters).
Not Observed/Not Expected. No known
records in the vicinity of the project.
Marginal habitat present on the project.
Eleven records were found in the vicinity.
The nearest was 4.1 miles away and
recorded in 1936.
Reptiles
Actinemys marmorata
Northwestern pond turtle
PT/CSC
Found in streams, ponds, lakes and permanent and
ephemeral streams.
Not Present. No suitable habitat present.
One record was found in the vicinity. It
was 5.0 miles away and recorded at an
unknown date.
Anniella grinnelli
Bakersfield legless lizard
-/CSC
Lives mostly underground and burrows in loose, sandy
soil in beach dunes, chaparral, pine-oak woodlands,
desert scrub, sandy washes, and stream terraces with
sycamores, cottonwoods, or oaks. Restricted to the
southern San Joaquin Valley and the east side of the
Carrizo Plain, including within Bakersfield city limits.
Not Observed/Not Expected. Suitable
habitat absent from the site. Limited
potential habitat in the vicinity.
Sixteen records were found in the vicinity.
The nearest was 3.4 miles away and
recorded in 1955.
Biological Resource Evaluation
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November 2025
26 Scientific Name
Common Name
Status
Federal/State General Habitat Survey Results/Regional or Nearest Occurrence* Anniella spp.
California legless lizard
-/CSC
Found in coastal dunes, chaparral, pine-oak
woodlands, desert scrub, and sandy washes in warm
moist loose soils, below 5,085 feet (1550 meters).
Not Observed/Not Expected. No
suitable habitat present. Limited potential
habitat in the project vicinity.
One record was found in the vicinity. It
was 7.6 miles away and recorded in
1939.
Arizona elegans occidentalis
California glossy snake
-/CSC
Found in low elevation scrub, grasslands and chaparral
habitats.
Not Present. No suitable habitat present.
Eight records were found in the vicinity.
The nearest was a record from 1946 that
was centered on the community of Old
River with an accuracy of one mile that
extended to the southern edge of the
project.
Gambelia sila
Blunt-nosed leopard lizard (BNLL)
E/E,SFP
Found only in the San Joaquin Valley, adjacent Carrizo
Plain, Elkhorn Plain, Cuyama Valley, and Panoche
Valley; inhabits sparsely vegetated plains, lower canyon slopes, on valley floors, and washes; open grassland,
saltbush scrub, and alkali sink are more common
habitat types.
Not Present. No suitable habitat present.
Seven records were found in the vicinity.
The nearest was 2.4 miles away and
recorded in 1968 and possibly has been
extirpated.
Masticophis flagellum
ruddocki
San Joaquin coachwhip -/CSC
Found in the San Joaquin Valley in open, dry habitats.
Associated with valley grassland and saltbush scrub
habitats containing small mammal burrows which are
used for refugia and oviposition sites.
Not Present. No suitable habitat present.
Four records were found in the vicinity.
The nearest was 1.3 miles away and
recorded in 2000.
Phrynosoma blainvillii
Coast horned lizard
S/CSC
Inhabits valley-foothill hardwood, coniferous and
riparian, as well as pine-cypress, juniper, and annual
grasslands, in Sierra Nevada below 3,937 feet (1,200
meters) and in mountains of Southern California and
into the adjacent valleys.
Not Present. No suitable habitat present.
Three records were found in the vicinity.
The nearest was 5.2 miles away and
recorded in 2006.
Thamnophis gigas
Giant garter snake
T/T Occurs in permanent or semi-permanent bodies of
water. Typically found in freshwater bodies of water, will be located in water features associated with farming
and irrigation (i.e. canals, drainage ditches flooded
fields).
Not Present. No suitable habitat present.
One record was found in the vicinity. It
was 9.8 miles away and recorded in 1949
and possibly has been extirpated.
Birds
Agelaius tricolor
Tricolored blackbird
S/T
Forages in grasslands, wetlands, rice fields, croplands, and weedy uplands dominated by mustards and
thistles, etc.; breeds in marshes containing heavy
growth of bulrushes, cattails, and blackberries; found
throughout the Central Valley.
Not Present/Low Probability of
Occurrence in the Project Vicinity. No
suitable nesting habitat on the site.
Potential for marginal foraging habitat in
farmlands in the vicinity of the project.
Biological Resource Evaluation
APN 540-010-19
November 2025
27 Scientific Name
Common Name
Status
Federal/State General Habitat Survey Results/Regional or Nearest Occurrence* Five records were found in the vicinity.
The nearest was 7.4 miles away and
recorded in 2014.
Anarhynchus nivosus nivosus
Western snowy plover
T/CSC Nests, feeds, and takes cover on sandy or gravelly beaches along the coast, on estuarine salt ponds, alkali lakes, and at the Salton Sea. On the Pacific coast, it
nests on barren to sparsely vegetated sand beaches,
dry salt flats in lagoons, dredge spoils deposited on
beach or dune habitat, levees and flats at saltevaporation ponds, and river bars.
Not Present/Not Expected. No suitable
nesting or foraging habitat on the site.
One record was found in the vicinity. It
was 8.3 miles away and has been
extirpated.
Athene cunicularia
Burrowing owl
S/C
Inhabits dry, open grasslands, rolling hills, desert floors, prairies, savannas, agricultural land, and other areas of open, bare ground. These owls will also inhabit open
areas near human habitation, such as airports, golf
courses, shoulders of roads, railroad embankments,
and the banks of irrigation ditches and reservoirs.
Not Observed/Moderate Probability of
Occurrence in the Project Vicinity.
Suitable habitat for nesting and foraging
in the vicinity of the project. No burrowing
owls or owl burrows observed.
Twenty-four records were found in the
vicinity. The nearest was 1.1 miles away
and recorded in 2004.
Buteo swainsoni
Swainson’s hawk
S/T
Riparian and sometimes large isolated trees used for
nesting; grasslands and agricultural lands used for
foraging; in California, breeds primarily in the
Sacramento Valley, with occasional nesting to the south through Kern County; migrate through the Central and
San Joaquin Valleys to their wintering grounds in South America.
Not Observed/Low Probability of
Occurrence in the Project Vicinity. No
suitable nesting sites on the project.
Unpreferred nesting sites are present in
the neighborhoods in the vicinity. Low
suitable foraging habitat exists across the
row-crop farmland south of metropolitan
Bakersfield.
Eight records were found in the vicinity.
The nearest was 4.8 miles away and
recorded in 2019.
Coccyzus americanus occidentalis
Western yellow-billed cuckoo
T/E
Nests in walnut and almond orchards in California,
natural nesting habitat is in cottonwood-tree willow
riparian forest. Known populations of breeding western
yellow-billed cuckoo are several disjunct locations in
California, Arizona, and western New Mexico.
Not Present. No suitable nesting habitat
exists on the project for this species. The
site represents poor foraging habitat.
One record was found in the vicinity. It
was 8.3 miles away and has been
extirpated.
Dendrocygna bicolor
Fulvous whistling duck -/CSC
Nests in fresh emergent wetlands and quiet riverine
waters. Uncommon to fairly common in the San
Joaquin Valley, April to November.
Not Present. No suitable nesting habitat
exists on the project for this species. The
site represents poor foraging habitat.
Biological Resource Evaluation
APN 540-010-19
November 2025
28 Scientific Name
Common Name
Status
Federal/State General Habitat Survey Results/Regional or Nearest Occurrence* One record was found in the vicinity. It
was 8.3 miles away and recorded in
1922.
Elanus leucurus
White tailed kite
S/SFP
Associated habitats include open grasslands,
savannahs, agriculture, wetlands, oak woodland and
riparian areas with associated open space.
Not Observed/Low Probability of
Occurrence in the Project Vicinity. No
suitable nesting sites on the project.
Suitable foraging habitat exists across the
row-crop farmland south of metropolitan
Bakersfield.
One record was found in the vicinity. It
was 5.5 miles away and recorded in
1992.
Eremophila alpestris actica
California horned lark
-/WL
Resident throughout California from the coast to the
deserts up to alpine dwarf-shrub habitat above tree line Not Observed/Moderate Probability of
Occurrence in the Project Vicinity.
Horned lark occur throughout the
southern San Joaquin Valley and
undoubtedly forage in the project vicinity.
Two records were found in the vicinity.
The nearest was 5.9 miles away and
recorded in 2006.
Gymnogyps californianus
California condor
E/E,SFP
Forages over large expanses of land including but not
limited to, grasslands, foothills, coastal mountain
ranges. Nests on cliff faces, large trees or manmade
structures.
Not Observed/Low Probability of
Occurrence in the Project Vicinity. No
suitable nesting habitat on the site.
Potential for marginal foraging habitat in
farmlands in the vicinity of the project.
Plegadis chihi
White-faced ibis
-/WL
Nesting associated with large emergent wetlands. Will
forage in a variety of wet meadows, irrigated pastures, flooded pond edges and wet cropland.
Not Present. No suitable nesting habitat
exists on the project for this species. The
site represents poor foraging habitat.
No records were found in the vicinity.
Vireo bellii pusillus
Least Bell's vireo
E/E Occurs in dense shrubby or scrubby habitat, including brushy fields, early successional growth, riverine scrub, coastal chaparral, scrub oak, mottes (isolated patches) of shrubs and trees in prairies, saltcedar stands, and
mesquite bosques. In arid regions, Bell’s vireos are
found along streams or in dry arroyos and gulches.
Not Present. No suitable nesting habitat
exists on the project for this species. The
site represents poor foraging habitat.
One record was found in the vicinity. The
nearest was 9.8 miles away, recorded in
1907, and possibly has been extirpated
Biological Resource Evaluation
APN 540-010-19
November 2025
29 Scientific Name
Common Name
Status
Federal/State General Habitat Survey Results/Regional or Nearest Occurrence* Xanthocephalus xanthocephalus
Yellow-headed blackbird
-/CSC
Yellow-headed blackbirds are found in freshwater
marshes during the summer. They particularly like to
live among cattails, tule, and bulrush. During migration and over winter months, the Yellow-headed Blackbird is
found in open, cultivated lands, in fields, and in
pastures.
Not Present. No suitable nesting habitat
exists on the project for this species. The
site represents poor foraging habitat.
One record was found in the vicinity. The
nearest was 8.3 miles away and recorded
in 1923.
Mammals
Ammospermophilus nelsoni
San Joaquin antelope squirrel
-/T
Found in grasslands or open shrublands; formerly more
extensive, current range includes southwestern portion
of the San Joaquin Valley and in adjacent valleys to the west.
Not Present. Beyond the current
published range of the species.
Three records were found in the vicinity.
The nearest was 6.8 miles away and
recorded in 1990.
Dipodomys ingens
Giant kangaroo rat
E/E
Western side of the San Joaquin Valley, including the
Carrizo Plain and the Panoche Valley; grassland and
shrub-land habitats with sparse vegetative cover and
soils that are well-drained, fine sandy loams with gentle slopes.
Not Present. Beyond the current
published range of the species.
One record was found in the vicinity. It
was 6.1 miles away and recorded in
1979.
Dipodomys nitratoides brevinasus
Short-nosed kangaroo rat
S/CSC
Found in arid communities on the valley floor portions
of Kern, Tulare, and Kings counties in scrub and
grassland communities in level to near-level terrain with alluvial fan-floodplain soil (fine sands and sandy loams) with sparse grasses and woody vegetation such as
iodine bush, saltbush, seep weed, and mesquite.
Not Present. Beyond the published
range of the species.
Two records were found in the vicinity.
The nearest was 8.7 miles away and
recorded in 1992.
Dipodomys nitratoides nitratoides
Tipton kangaroo rat
E/E
Found in arid communities on the valley floor portions
of Kern, Tulare, and Kings counties in scrub and
grassland communities in level to near-level terrain with alluvial fan-floodplain soil (fine sands and sandy loams) with sparse grasses and woody vegetation such as
iodine bush, saltbush, seep weed, and mesquite.
Low Probability of Occurrence. Habitat
suitable for Dipodomys sp. The project is
not within the southwest focus area of the
previous Habitat Conservation Plan. No
stereotypical kangaroo rat burrows were
observed. Small mammal trapping would
be required to determine species
occupation.
Ten records were found in the vicinity.
The nearest was 3.2 miles away and
recorded in 1990.
Eumops perotis californicus
Greater western mastiff bat S/CSC
Open, semi-arid to arid habitats, including conifer and deciduous woodlands, annual and perennial
grasslands, chaparral, desert scrub, and urban areas;
roosts in cliff faces, as well as high buildings, trees, and No Roosting Sites Present. No known
occurrences in the vicinity of the project.
Information on some bat species
indicates foraging may occur over 10’s of
Biological Resource Evaluation
APN 540-010-19
November 2025
30 Scientific Name
Common Name
Status
Federal/State General Habitat Survey Results/Regional or Nearest Occurrence* tunnels; uncommon resident in southwestern San
Joaquin Valley.
miles from roosting sites. Impacts not
expected.
Two records were found in the vicinity.
The nearest was 6.5 miles away and
recorded at an unknown date.
Onychomys torridus tularensis
Tulare grasshopper mouse
S/CSC
Found in valley grasslands habitats, blue oak savanna,
desert associations dominated by annual grasses and
California ephedra, alkali sink scrub, saltbush scrub,
and upper Sonoran shrub associations, dominated by
ephedra.
Not Observed/Not Expected. Beyond
the current published range of the
species.
Five records were found in the vicinity.
The nearest was 2.4 miles away and
recorded in 1891.
Perognathus inornatus inornatus
San Joaquin pocket mouse
S/-
Found in west-central California in the Upper
Sacramento Valley, Tehama County, southward
through the San Joaquin and Salinas valleys and
contiguous areas to the Mojave Desert in Los Angeles,
Kern and extreme western San Bernardino counties.
Inhabits dry, open, grassy or weedy areas and annual
grasslands, savannas, and desert-scrub associations
with sandy washes or finely textured soils.
Not Observed/Not Expected. Beyond
the current published range of the
species.
Two records were found in the vicinity.
The nearest was 5.2 miles away and
recorded in 2016.
Sorex ornatus relictus
Buena Vista Lake shrew
E/CSC
Formerly occupied marshlands of the San Joaquin
Valley and the Tulare Basin. Its range has become
much restricted due to the loss of lakes and sloughs in the area. It has been recorded from the Kern Lake
Preserve area and the Kern National Wildlife Refuge.
Current distribution is unknown but likely to be very
restricted due to the loss of habitat.
Not Present. No suitable habitat present.
Three records were found in the vicinity.
The nearest was 6.1 miles away and
recorded in 2000.
Taxidea taxus
American badger
-/CSC
Uncommon resident found through California; in less
disturbed grassland and shrubland habitats in San
Joaquin Valley.
Not Present No suitable habitat present.
Three records were found in the vicinity.
The nearest was 2.4 miles away and
recorded in 1900.
Vulpes macrotis mutica
San Joaquin kit fox (SJKF)
E/T
Found in valley saltbush scrub, valley sink scrub,
Interior Coast Range saltbush scrub, upper Sonoran
sub-shrub scrub, non-native grassland, and valley
sacaton grassland in the Central Valley and adjacent
foothills and valleys, infrequently to the outer Coast
Ranges; generally not found in densely wooded areas,
wetland areas, or areas subject to frequent periodic
flooding.
Moderate to High Probability of
Occurrence. No potential, known, or
natal dens were observed. SJKF potential
for occurrence moderate to high in the
vicinity of the project. SJKF are known to
occupy metropolitan Bakersfield.
Biological Resource Evaluation
APN 540-010-19
November 2025
31 Scientific Name
Common Name
Status
Federal/State General Habitat Survey Results/Regional or Nearest Occurrence* Thirty-nine records were found in the
vicinity. The nearest was 0.8 miles away
and recorded in 2006.
STATUS:
Federal
S Listed as a BLM Sensitive Species
D Delisted
E Listed as Endangered
PT Proposed as Threatened
T Listed as Threatened
State
C Candidate for Endangered Status
CSC California Department of Fish and Wildlife Designated Species of Special Concern
D Delisted
E Listed as Endangered
SFP California Department of Fish and Wildlife Designated Fully Protected
T Listed as Threatened
Biological Resource Evaluation
APN 540-010-19
November 2025
32 Figure B-1. CNDDB special-status plant species occurrences within a 10-mile radius of the project (CDFW 2025).
Biological Resource Evaluation
APN 540-010-19
November 2025
33 Figure B-2. CNDDB special-status bird species occurrences within a 10-mile radius of the project (CDFW 2025).
Biological Resource Evaluation
APN 540-010-19
November 2025
34 Figure B-3. CNDDB special-status amphibian and reptile species occurrences within a 10-mile radius of the project (CDFW 2025).
Biological Resource Evaluation
APN 540-010-19
November 2025
35 Figure B-4. CNDDB special-status mammal species occurrences within a 10-mile radius of the project (CDFW 2025).
Biological Resource Evaluation
APN 540-010-19
November 2025
36 Figure B-5. CNDDB special-status invertebrate species occurrences within a 10-mile radius of the project (CDFW 2025).
APPENDIX C
PLANTS AND ANIMALS OBSERVED ON THE PROJECT
FIELD STUDY CONDUCTED
November 14, 2025
APPENDIX C
PLANTS AND ANIMALS OBSERVED ON THE PROJECT
FIELD STUDY CONDUCTED
November 14, 2025
Biological Resource Evaluation
APN 540-010-19
November 2025
Table C-1. Vascular plant species observed during the field study conducted on the project site.
Scientific Name Common Name
Amaranthaceae
Amaranthus palmeri Palmer’s amaranth
Asteraceae
Taraxacum officinale Common dandelion
Chenopodiaceae
Salsola tragus Russian thistle
Fabaceae
Pisum sativum Common pea
Malvaceae
Malva leprosa Alkali mallow
Malva parviflora Cheeseweed
Poaceae
Cynodon dactylon Bermudagrass
Leptochloa fascicularis Sprangletop
Poa annua Annual bluegrass
Zygophyllaceae
Tribulus terrestris Punctervine
Table C-2. Vertebrate animal species observed during the field study conducted on the project site.
Scientific Name Common Name
Birds
Corvus corax Common raven
Passer domesticus House sparrow
Zenaida macroura Mourning dove
Mammals
Botta’s pocket gopher Thomomys bottae (sign)
Attachment B
LandStone Companies – Old River and
McCutchen
Biological Survey Report