Appendix X Status and Life History of the San Joaquin Kit Fox ( Vulpes macrotis mutica )

1.1 Species Listing Status (ok)

The San Joaquin kit fox ( Vulpes macrotis mutica ) was listed as endangered on March 11, 1967 (32 FR 4001) by the U.S. Fish and W ildlife Service (USFWS) (USFWS, 1967). A recovery plan for upland species of the San Joaquin Valley was approved by the USFWS on September 30, 1998 (USFWS, 1998).

1.2 Description and Taxonomy (ok)

Generally, kit foxes are char acterized by “a small, slim body, relatively large ears set close together, narrow nose, and a long bushy ta il tapering slightly toward the tip. The tail is typically carried lo w and straight” (USFWS, 1998). The kit fox is the smallest species in North America in the “Canid ae family, which includes dogs, wolves and foxes” (USFWS, 1998 and 2008). San Joaquin kit foxes (SJKF) ha ve “an average body length of 20 inches and weight of about 5 pounds” (USFWS, 2008). However,

differences between males and females exis t. “Males averaged 80.5 centimeters (31.7 inches) in total length, and 29.5 centimeters (11. 6 inches) in tail length; females averaged 76.9 centimeters (30.3 inches) in total lengt h, and 28.4 centimeters (11.2 inches) in tail length” (USFWS, 1998). Kit foxes are about “30 centimeters (12 inches) high at the shoulder” (USFWS, 1998). “T he average weight of adult males is 2.3 kilograms (5 pounds), and of adult females at 2.1 kil ograms (4.6 pounds)” (USFWS, 1998). The

“color and texture of the fur coat of kit foxes varies geographically and seasonally” (USFWS, 1998). “Two distinctive coats de velop each year: a tan summer coat and a sliver-gray winter coat. The undersides vary from light buff to white, with the shoulders, lower sides, flanks and chest varying from buf f to a rust color. The ear pinna (external ear flap) is dark on the back side, with a th ick border of white ha irs on the forward-inner edge and inner base. The tail is di stinctly black-tipped” (USFWS, 1998).

Historically, eight subspecies of kit fox ( V. macrotis ) were recognized (USFWS, 1998). However, “several different taxonomies for th e species and subspecies of small, North American foxes have been proposed over th e last 110 years” (USF WS, 1998). A study published in 1990 “concluded that all North Am erican arid-land foxes belonged to the species V. velox (swift fox)” (USFWS, 1998). Th is study also challenged the “subspecific statuses of the taxa hist orically regarded as subspecies of V. macrotis ” and “recommended that all be synonymized under V. velox macrotis ” (USFWS, 1998). A genetic study published in 1993 suggeste d that “though there was evidence of hybridization between kit and sw ift foxes over a limited geographic area, they should be considered separate species” (USFWS, 1998). This study also determined that “of the traditional subspecies of the kit fox, the San Joaquin Valley population is the most

distinct and should be consid ered a subspecies” (USFWS, 19 98). The data from this study recognize “two subspecies of kit foxes: V. macrotis macrotis , found throughout the remaining habitat within the historical rang e of the species, except the San Joaquin kit fox range; and V. macrotis mutica , the San Joaquin kit fox” (USFWS, 1998). “The San

1Joaquin kit fox is the largest subspecies in skeletal measurements, body size, and weight” (USFWS, 1998). “The type locality is near Tracy, San Joaquin County, California” (USFWS, 1998).

1.3 Distribution and Status

Historical Range: (ok) “Although the San Joaquin kit fox has been list ed as endangered for over 30 years, there has never been a comprehensive survey of its entire historical range. And, despite the loss of habitat and apparent decline in numb ers since the early 1970s, there has been no new survey of habitat that was then thought to be occupied” (USFWS, 1998).

“As early as 1925,” kit foxes were reported “fro m the Panoche Creek area in the foothills of western Fresno County, and east of Rose Station (Fort Tejon) in southern Kern County

at an elevation of 363 meters (1,200 feet)” (USFWS, 1998). It is likely th at kit foxes “have always occurred in these areas” just at low densities (USFWS , 1998). “Prior to 1930, kit foxes inhabited most of the San Joaquin Valley from southern Kern County north to Tracy, San Joaquin County, on the west side, and near La Grange, Stanislaus County, on the east side” (USFWS, 1998 and 2008) . Another USFWS so urce stated that the range extended farther west to Contra Co sta County on the west side (USFWS, 1998). “Tracy was the farthest northwest record ” until the 1990s; however, records now exist

“from the Antioch area of Contra Costa County” (USFWS, 2008). “By 1930, the kit fox range had been reduced by more than half, with the largest portion remaining in the southern and western parts of the Va lley” (USFWS, 1998 and 2008). However, no indication was provided for why it was believed that the foxes “had been eliminated from

most of the east side and Valley floor” (USFWS, 1998).

Current Range: (ok) “The San Joaquin kit fox is found only in th e Central Valley area of California” (East Contra Costa County HCP/NCCP, 2006). “The distribution of kit foxes in California includes all or portions of Alameda, C ontra Costa, Fresno, Kern, Kings, Merced, Monterey, San Benito, San Joaquin, San Luis Obispo, Santa Barbara and Tulare counties” (SJCOG). Stanislaus, Madera, Sant a Clara, and Ventura counties should also

be included in the list above. The counties are divided into the three regions (northern, central, and southern) which consist of the following c ounties: northern (Alameda, Contra Costa, San Joaquin, and Santa Clara) , central (Fresno, Kings, Madera, Merced, San Benito, Stanislaus, and Tulare), and sout hern (Monterey, Kern, San Luis Obispo, and Santa Barbara) (Cal. EPA. Dept of Pesticide Regulation, 2002).

“Despite the lack of a comprehensive surv ey, local surveys, research projects and incidental sightings indicate th at kit foxes currently inhabit some areas of suitable habitat on the San Joaquin Valley floor and in the surrounding foothills of the coastal ranges, Sierra Nevada, and Tehachapi Mountains, fr om southern Kern County north to Contra Costa, Alameda, and San Joaquin Counties on the west, and near La Grange, Stanislaus County on the east side of the Valley, and some of the larger scattered islands of natural land on the Valley floor in Kern, Tulare, Ki ngs, Fresno, Madera, and Merced Counties.

2Kit foxes also occur westward into the inte rior coastal ranges in Monterey, San Benito, and Santa Clara Counties (Pajaro River wate rshed), in the Salinas River watershed, Monterey and San Luis Obispo, and in the upper Cuyama River watershed in northern

Ventura and Santa Barbara Counties and s outheastern San Luis Obispo County. Kit

foxes are also known to live with in the city limits of the c ity of Bakersfield in Kern County” (USFWS, 1998).

“The largest extant populations of kit f oxes are in western Kern County on and around the Elk Hills and Buena Vista Valley, Kern County, and in the Carrizo Plain Natural Area, San Luis Obispo County. The kit fox pop ulations of Elk Hills and the City of Bakersfield, Kern County, Carrizo Plain Na tural Area, San Luis Obispo County, CiervoPanoche Natural Area, Fresno and San Benito Counties, Fort Hunter Liggett, Monterey County, and Camp Roberts, Monterey and San Luis Obispo Counties have been recently, or are currently, the focus of various research projects. Though monitoring has not been continuous in the central and northern portions of the range, populations were recorded in the late 1980s at San Luis Reservoir, Me rced County, North Gra sslands and Kesterson National Wildlife Refuge area on the Valle y floor, Merced County, and in the Los Vaqueros watershed, Contra Costa County in the early 1990s. Sma ller populations and isolated sightings of kit foxes are also know n from other parts of the San Joaquin Valley floor, including Madera County and eastern Stanislaus County” (USFWS, 1998).

“The kit fox population is fragmented, particularly in the northern part of the range” (USFWS, 2008). The habitat is in the northern part of the range “is not as good as it is to

the south because there’s not as much of it” and “it’s pinched between heavy agricultural

land and coastal mountains” as a result there ar e “not as many kit foxes there” (Ridgley, 2007). “A recent survey of Contra Cost a County and Alameda Counties within the known range of the San Joaquin kit fox f ound no evidence of recent occupancy” (East Contra Costa County HCP/NCCP, 2006). “D espite a total of 139.4 km surveyed” “in

2002 in Contra Costa and Alameda Counties (81.0 km in Contra Costa County), no sign of San Joaquin kit fox was found” (Eas t Contra Costa County HCP/NCCP, 2006). “These results do not prove absence of kit f ox from the inventory area (e.g., no private land was surveyed with detection dogs), but do suggest that kit fox density is low or their occurrence is periodic in the inventory area” (East Contra Costa County HCP/NCCP, 2006).

Status: (ok) The estimated range-wide population “of adu lt kit foxes prior to 1930 may have been between 8,667 and 12,134 assuming an occupi ed range of 22,447 square kilometers (8,667 square miles)” (USFWS, 1998). A study published in 1970 “reported an estimated total population size of 1,000 to 3,000 foxes in 1969” (USFWS, 1998). In the early 1970s, the “kit fox population in San Luis Obisp o, Santa Barbara, Kings, Tulare and Kern Counties was estimated to be about 11,000 animals” (USFWS, 1998). However, this number was “based on limited aerial survey s of pupping dens and amount of historic habitat, but without correction for cultivat ed and urbanized lands” (USFWS, 1998). A study published in 1975 “conducted a more thor ough investigation of kit fox abundance

in 14 counties in which kit foxes were known to occur and estimated the total population

3at 14,832” (USFWS, 1998). These data were adjusted in th e 1983 recovery plan for the kit fox and “a corrected estimate of 6,961 f oxes in 1975 was obtained” (USFWS, 1998). “When compared to the pre-1930 estimate, this represents a possible population decline of 20 to 43 percent. Approximately 85 pe rcent of the fox populat ion in 1975 was found in only six counties (Kern, Tulare, Kings, Sa n Luis Obispo, Fresno, and Monterey), and over half the population occurred in two of those counties: Kern (41 percent) and San Luis Obispo (10 percent)” (USFWS, 1998).

1.3.1 Critical Habitat (ok)

No critical habitat for the SJKF has been designated by the USFWS to date.

1.4 Habitat

“Historically, San Joaquin kit foxes occurred in several Sa n Joaquin Valley native plant communities” (USFWS, 1998 and 2008). Howeve r, due to “extensive land conversion and intensive land use, some of these communities” “are represented by small, degraded remnants today” (USFWS, 1998). “San Joaquin kit foxes occur in a variety of habitats, including grasslands, scrublands, vernal pool areas, alkali meadows and playas, and an agricultural matrix of row crops, irrigated pastures, orchards, vineyards, and grazed annual grasslands” (East Contra Costa Count y HCP/NCCP, 2006). The recovery plan states that the plant communities associated with the San Joaquin Kit Fox are grasslands, chenopod scrub, alkali sink, subshrub scrub, oak woodland, and ag riculture (USFWS, 1998). “Other plant communities in the Sa n Joaquin Valley providing kit fox habitat include Northern Hardpan Vernal Pool, Nort hern Claypan Vernal Pool, Alkali Meadow, and Alkali Playa. These are found as relativel y small patches in scattered locations. In general, they do not provide good denning habitat for kit foxes because all have moist or waterlogged clay or clay-like soils. Howeve r, where they are interspersed with more suitable kit fox habitats they provide f ood and cover” (USFWS, 1998). “Kit foxes use some types of agricultural land where unc ultivated land is maintained, allowing for denning sites and a suitable prey base. K it foxes also den on small parcels of native habitat surrounded by intensively maintained agricultural lands and adjacent to dryland farms” (USFWS, 1998). “Other habitats in wh ich kit foxes are curre ntly found have been extensively modified by humans” (USFWS, 1998 ). Kit foxes are “f ound in grassland and scrubland communities with active oil fields, wi nd turbines, and an agricultural matrix of row crops, irrigated pasture, orchards, vineyards, and grazed annual grasslands (nonirrigated pasture)” (USFWS, 1998 and 2008).

“In the southernmost portion of the range, the kit fox is commonly associated with Valley Sink Scrub, Valley Saltbush Scrub, Uppe r Sonoran Subshrub Scrub, and Annual Grassland” (USFWS, 1998 a nd 2008). “Kit foxes also in habit grazed grasslands, petroleum fields, urban areas, and survive adj acent to tilled or fallow fields. In the central portion of the range, the kit fox is associated with Valley Sink Scrub, Interior Coast Range Saltbush Scrub, Upper Sonoran Subshrub Scrub, Annual Grassland and the remaining native grasslands. Agriculture dominates this region where kit foxes mostly inhabit grazed, nonirrigated grassl ands, but also live next to and forage in tilled or fallow

4fields, irrigated row crops, or chards, and vineyards. In th e northern portion of their range, kit foxes commonly are associated with annual grassl and and Valley Oak Woodland. Kit foxes inhabit grazed grasslands , grasslands with wind turbines, and also live adjacent to and forage in tilled and fallow fields, and irrigated row crops” (USFWS, 1998).

“San Joaquin kit foxes use dens for temp erature regulation, shelter from adverse environmental conditions, reproduction, and es cape from predators” (USFWS, 1998 and 2008). “Kit foxes prefer loose textured soils, but are found on virtually every soil type. Dens appear to be scarce in areas with sha llow soils because of the proximity to bedrock, high water tables, or impenetr able hardpan layers. However, kit foxes will occupy soils with a high clay content, such as in th e Altamont Pass area in Alameda County, where they modify burrows dug by other animals” (USFWS, 1998). Kit foxes dig their own dens, modify and use those already constr ucted by other animals (ground squirrels, badgers, and coyotes), or use human-made stru ctures (culverts, abandoned pipelines, or banks in sumps or roadbeds) (USFWS, 1998 and 2008). “Though kit foxes are reputed to be poor diggers, the complexity and depth of their dens do not support this assessment” (USFWS, 1998).

“The majority of their dens lie in relatively fl at terrain or gently sloping hills, in washes, drainages, and roadside berms” (Cal. EPA. Dept of Pesticide Regulation, 2002). “Dens are generally located in open areas with grass or grass a nd scattered brush, and seldom

occur in areas with thick brush. Preferred si tes are relatively flat, well-drained terrain” (East Contra Costa County HCP/NCCP, 2006). “Most hillsides where kit fox dens are found (95 percent) have a slope of less th an 40 degrees. Natal and pupping dens are found on flatter ground with slope s of about 6 degrees” (USFWS, 1998). However, “den characteristics vary across the San Joaquin kit fox’s geographic ra nge” (USFWS, 1998). “In western Merced County, most dens are found on slopes of less th an 10 degrees, but a few are found on slopes of up to 55 degrees. In the northern portion of the kit fox range, dens appeared to be placed higher than most surrounding ground compared to areas farther south, perhaps reflecting the topography of the area. Dens mo st often are located on the lower section of the slope, yet foxes are sometimes seen entering dens on the upper part of a slope” (USFWS, 1998). “Kit foxes in the northern range are found in higher elevations than those in the southern range” (SJCOG).

Kit foxes “often change dens and many dens may be used throughout the year” (USFWS, 1998 and 2008). “Foxes change dens four or five times during the summer months, and change natal dens one or two times per mont h” (USFWS, 1998). “Radiotelemetry studies

indicate that foxes us e individual dens for a median of 2 days (mean of 3.5 days) before moving to a different den” (USFWS, 1998). It has been determined that “den use does not differentiate between sexes” (East Contra Costa County HCP/NCCP, 2006). However, “the number of dens used varied among seasons, with more dens used during the dispersal season than during the breeding or pup-rearing seasons” (East Contra Costa County HCP/NCCP, 2006). “Den changes have b een attributed to depletion of prey in the vicinity of the den or to increases in ex ternal parasites such as fleas. Avoidance of coyotes is a more probably reason for freque ntly changing dens because kit foxes can

5easily search their home range in one night for prey, and parasites are unlikely to build to intolerable levels in 2 or 3 days” (USFWS, 1998).

Core Areas: (ok) “Three core populations are: 1) Carrizo Plain Natural Area in San Luis Obispo County; 2) Natural lands of western Kern County (i .e., Elk Hills, Buena Vista Hill, and the Buena Vista Valley, Lokern Natural Area and adjacent natural land) inhabited by kit foxes; and 3) The Ciervo-Panoche Natural Area of western Fresno and eastern San Benito Counties” (USFWS, 1998).

The Carrizo Plain Natural Area when “combined with land owned by The Nature Conservancy, provides more than 200,000 acres of relatively pr istine kit fox habitat about 55 miles west of Bakersfield” (Ridgley, 2007). The second area is “a mosaic of disjointed parcels totaling an estimate d 300,000 to 500,000 acres” “scattered throughout public and private land in western Kern County about 30 miles west of Bakersfield” (Ridgley, 2007). This area is “perfect kit fox territory – except for the two hazardous waste sites nearby and the miles of oil pipeline that run below the sand” (Ridgley, 2007). Kern County is “the third-largest crude oil production area in the country after Alaska and Texas” (Ridgley, 2007). However, this area “still supports more foxes than that of less-developed land in the count y” (Ridgley, 2007). “The Ciervo-Panoche Natural Area population is located more than 160 kilometers (100 miles) northwest of the other two core populations. As with the other core popul ations, it has significant numbers of foxes, at least it had historically and it still may from time to time” (USFWS, 1998). “Foxes do subsist here, but it’s uncertain whether th ey are really a core population or just a ‘satellite’ group” (Ridgley, 2007). “Lands fa rther north, where foxes have also been intermittently observed, are even more marginal” (Ridgley, 2007).

These three core populations are geographically distinct even though they are “more or less connected to each other by grazing la nds, although they are steep and rugged in many places” (USFWS, 1998). “The west ern Kern County and Carrizo Plain populations, although geographically close, are separated by the Temblor Range” (USFWS, 1998). “Kit foxes occur at varying densities in the areas between the core populations (e.g., Kettleman Hills), providing linkages between the core populations, and also probably with smaller, more isolated populations in adjace nt valleys” (USFWS, 1998). “Preliminary population viability analys es indicate that exti nction probabilities increase dramatically if either it Carriz o Plain or western Ke rn County population is eliminated” (USFWS, 1998).

“Important kit fox populations in the Salinas-Pajaro Region (herein de fined as the area of the Salinas River and Pajaro River watersheds with habitat for kit foxes); are located at Camp Roberts and Fort Hunter Liggett in the Salinas River Watershed. Though there are natural connections between the Salinas-Paja ro Region, the Carrizo Plain Natural Area, and the San Joaquin Valley, the amount of m ovement of kit foxes between the SalinasPajaro Region and these areas is unknown, t hough one fox is known to have moved from

6Camp Roberts to the Carrizo Plain” (USFWS, 1998). Kit f oxes can also be found on the Lemoore Naval Air Station, as well as on “p rivate lands in western Madera County, central, western, and eastern Merced County, eastern Stanis laus County, northern Kings County, around Pixley National Wildlife Refuge and Allensworth Ecological Reserve in Tulare County, Semitropic Ridge Natural Area and around the Bakersfield metropolitan area of Kern County” (USFWS, 1998). In a ddition, the “California Department of Water Resources’s Kern Fan Element provides an im portant linkage between kit foxes along the Kern River Parkway in Bakersfield and th e western Kern County core population” (USFWS, 1998).

Activity, Movement, and Behavior: (ok) Kit foxes are predominantly nocturnal and “most above-gro und activities begin near sunset and continue sporad ically throughout the night” (U SFWS, 1998). However, some populations of kit foxes prey on “ground squi rrels, which are ac tive during the day” indicating that kit foxe s are not strictly nocturnal and that they have adapted to the

activities of their available prey (USFWS, 1998). In addition, kit foxes are “commonly seen during the day during late spring and ear ly summer” (USFWS, 1998 ). They are also “active throughout the year” (USFWS, 1998).

Based on observations at the Elk Hills Naval Pe troleum Reserves in California, kit foxes move an average of 15.4 kilometers (9.6 mile s) nightly during the breeding season which is “significantly longer than the averag e nightly movements of 10.2 kilometers (6.3 miles) during the pup-rearing season. Move ments during the breeding season also were significantly longer than those made during th e pup-dispersal season (10.4 kilometers, 6.5 miles)” (USFWS, 1998).

Kit foxes are a “wide ranging species with established home ranges generally between 1- 3 square miles, but they can be as large as 12 square miles” (SJCOG and USFWS, 1998). “Foxes in nonurban areas had larger home ranges than those in urban areas” (Ralls, 2007). “The maintenance of large and relatively non-overlap ping home ranges, as noted on the Carrizo Plain, may be an adaptation to drought-induced periods of prey scarcity that are episodic and temporar y on the Carrizo Plain. Diffe rences in home range size among study sites tend to be relate d to prey abundance” (USFWS, 1998).

Life History and Ecology (ok)

Life history and ecology information about the SJKF, including diet, reproduction, and disease, competition, and predation are pr ovided in the sections below (1.5.1 through 1.5.3).

1.5.1. Diet (ok) The diet of the SJKF “varies geographical ly, seasonally and annua lly, based on variationin abundance of potential prey” (USFWS, 1998). “In the southern part of the range, onethird of the kit fox diet c onsists of kangaroo rats ( Dipodomys spp.), pocket mice ( Perognathus spp.), white-footed mice ( Peromyscus spp.) and other nocturnal rodents. Kit foxes in this area also prey on California ground squirrels ( Spermophilus beecheyi ),

7black-tailed hares ( Lepus californicus ), San Joaquin antelope squirrels ( Ammospermophilus nelsoni ), desert cottontails ( Sylvilagus audubonii ), ground-nesting birds and insects” (USFWS, 1998) . “Vegetation and insects o ccur frequently in feces. Grass is the most commonly ingested plant material” (U SFWS, 1998). “In the central portion of their geographic ra nge, defined here as Kings , Tulare, Fresno, Madera, San Benito, Merced, Stanislaus, and Monterey Counties, known prey species include whitefooted mice, insects, California ground squi rrels, kangaroo rats, San Joaquin antelope squirrels, black-tailed hares, and chukar ( Alectoris chukar ), listed in approximate proportion of occurrence in fecal samples” (USF WS, 1998). “In the northern part of their range, defined here as San Joaquin, Alameda and Contra Costa Counties, kit foxes most frequently consume California ground squi rrels” (USFWS, 1998). Cottontails, blacktailed hares, pocket mice, and kangaroo rats are also eaten” (USFWS, 1998).

1.5.2. Reproduction (ok) Kit foxes can breed when they are one year old, but they may not br eed during their first year of adulthood (USFWS, 1998 and 2008). “Adult pairs remain together all year, sharing the home range but not necessarily the same den. During September and October, adult females begin to clean and enla rge natal or pupping dens (they select dens with multiple openings). Mating and concep tion take place between late December and March. The median gestation period is estimate d to range from 48 to 52 days. Litters of from two to six pups are born sometime betw een February and late March” (USFWS, 1998 and 2008). “The female is rarely seen hunting during the time she is lactating. During this period the male provides most of the food for her and the pups. The pups emerge above ground at slightly more than one month of age” (USFWS, 1998 and 2008). “After 4 to 5 months, usually in August or September,” the young begin to disperse (USFWS, 1998). “Occasionally a juvenile fema le will remain with the adult female for several more months” and “offspring of both sexes sometimes remain with their parents through the following year and help raise a subsequent litter” (USFWS, 1998).

A study of 209 dispersing juveniles publishe d in 2000 found that “33% dispersed from their natal territory,” and “significantly more males (49%) than fema les (24%)” dispersed (East Contra Costa County HCP/NCCP, 2006). “Most of the dispersing juveniles (65%) died within 10 days of leaving their natal range. However, su rvival tended to be higher for dispersing males than for males that rema ined within their natal area. There was no difference in survival for dispersing and phil opatric females” (East Contra Costa County HCP/NCCP, 2006). Dispersal distances can vary substantially. “Duri ng a 6-year study at

the Elk Hills Naval Petroleum Reserves in Ca lifornia, pups dispersed an average of 8±1.4 kilometers (5±0.9 miles)” (USFWS, 1998). “O ne individual traveled a minimum of 40 kilometers (25 miles) from its whelping de n, and a prime adult male dispersed from Camp Roberts to the Carrizo Plan in 1989” (U SFWS, 1998). Both adults and juveniles at

the Elk Hills Naval Petroleum Reserves “dis persed through disturbe d habitats, including agricultural fields, oil fiel ds, rangelands, and across hi ghways and aqueducts. One pup crossed the Temblor Range into th e Carrizo Plain” (USFWS, 1998).

“The annual reproductive success for adults can range between 20 and 100% (mean: 61%) and 0 and 100% for juveniles (mean: 18%). Population growth rates generally vary

8positively with reproductive success and kit fox de nsity is often positivel y related to both current and the previous year’s prey availability. Prey abundance is generally strongly related to the previous year’s effective (O ctober to May) precipitation” (East Contra Costa County HCP/NCCP, 2006). “The density of prey species drops because of drought, too much rainfall, or other circ umstances” (USFWS, 1998). “Adults can maintain weight and body condition and fema les can give birth, but pairs apparently cannot catch enough prey to support the pups” (USFWS, 1998). Typically the “pups are born but do not survive to weaning” (USFWS , 1998). Biologists studying foxes on the Naval Petroleum Reserve in Kern County have determined that “the population size of

these foxes can fluctuate greatly” (Bell, 1995).

Longevity: (ok) In captivity, kit foxes have lived up to 10 years” (USFWS, 1998). “Kit foxes on Naval

Petroleum Reserve-1 in California are known to live as long as 8 year s” and “kit foxes at Camp Roberts are reported to be over 8 years old” (USFWS, 1998). However, “such longevity is rare” and “animals less than 1 year old outnumber older foxes by 2.8:1” (USFWS, 1998).

The annual adult kit fox mortality rate is approximately 50 percent in nonurban populations and “the annual mortality rate for juvenile kit foxe s may be close to 70 percent” (USFWS, 1998 and Ralls, 2007). “In contrast, annual mortality in urban Bakersfield, California, is lower (about 30%)” (Ralls, 2007). “Annua l survival rates of juvenile foxes have ranged from 0.26 on Na val Petroleum Reserve-1 in California to 0.21 to 0.41 on the Carrizo Plain” (USFWS, 1998).

1.5.3. Disease, Competition, and Predation (ok) “The effects of disease, parasites and acci dental death are largely unknown, but were thought to account for only a small porti on of mortality” (USFWS, 1998). Although “disease does not appear to be a significant source of mortality,” “rabies could have contributed to a decline in one population of the San Joaquin kit f ox” (List and Cypher, 2004). Numbers of SJKF caught during “annua l livetrapping sessions at the California Army National Guard Training Site, Camp Robe rts, decreased from 103 to 20 individuals

from 1988 to 1991. This decrease conti nued through 1997 when only three kit foxes were captured” (White et al., 2000). “An out break of rabies virus may have contributed to this catastrophic decrease in abundance because two foxes were found dead due to rabies in 1990” (White et al., 2000). The recovery plan also states that “at Camp Roberts rabies accounted for 6.3 percent of deaths of ra dio-collared kit foxes and there is concern that rabies may be a contri buting factor in the recent de cline of kit foxes at Camp Roberts” (USFWS, 1998). “Interference competition by coyotes ( Canis latrans ) also may have contributed to this catastrophic de crease because relative abundances of foxes and coyotes were negatively correlated from 1988 to 1997, and coyotes were responsible for 59% of fox deaths during a 4-year te lemetry study (1988 to 1991)” (White et al., 2000).

“Kit foxes are subject to competitive exclusion or predation by other species, such as the nonnative red fox ( Vulpes vulpes ), coyote ( Canis latrans ), domestic dog ( Canis

9familiaris ), bobcat ( Felis rufus ), and large raptors” (USF WS, 1998 and 2008). “Predation by larger carnivores (e.g., c oyotes) accounts for the major ity of San Joaquin kit fox mortality” particularly in nonurban areas (USFWS, 1998 a nd Ralls, 2007). In urban Bakersfield, California “motor ve hicles are the major cause of death. No sex or seasonal differences in vulnerability to predation are known” (Ralls, 2007). However, higher proportions of juvenile kit foxe s are typically killed by coyot es at higher fox densities (East Contra Costa County HCP/NCCP, 2006). “The mortality rates of adult foxes are apparently independent of population density” (East Cont ra Costa County HCP/NCCP, 2006). “Coyotes are known to kill kit foxes, though an experimental coyote-control program at the Elk Hills Naval Petroleum Rese rves in California did not result in an increase in survival rates for kit foxes, nor did coyote-induced mortality decrease” (USFWS, 1998).

Nonnative red foxes and kit foxes are likely to be in direct competition with each other for similar den sites and prey species (USFWS, 1998). “Nonnative red foxes are expanding their geographic range in central Ca lifornia, and competition with or predation on kit foxes may be a factor in the apparent d ecline of kit foxes in the Santa Clara Valley, and perhaps elsewhere in the northwester n segment of their range” (USFWS, 1998). “Coyotes may reduce the negative impacts of red foxes on kit foxes by limiting red fox abundance and distribution, but details of inte ractions between the two species and the extent to which coyotes might slow or prev ent the invasion on red foxes into kit fox habitats are unknown” (USFWS, 1998).

1.6 References

Bell, H. 1995. San Joaquin Kit Fox. Tideline. Vol. 15 No. 3 1-3. Available online at: http://www.fws.gov/desfbay/Archives/Fox/KitFox.htm (Accessed on October 3, 2007).

Cal EPA. Dept. of Pesticide Regulation. 2002. San Joaquin Kit Fox (Vulpes macrotis mutica). Available online at: http://www.cdpr.ca.gov/docs/ endspec/espdfs/sjkfall.pdf (Accessed on April 4, 2008).

East Contra Costa County HCP/NCCP. 2006. San Joaquin Kit Fox (Vulpes macrotus mutica). Available online at: http://www.co.contracosta.ca.us/depart/cd/water/HCP/archive /hcp_nccp_content/hcp_nccp/app_figs/App%20 D%20components/App_D-02a_Sa n_Joaquin_kit_fox_profile_1-18-05.pdf (Accessed on April 3, 2008).

List, R. and B.L. Cypher. 2004. Kit fox ( Vulpes macrotis ). Pages 105-109 in C. SilleroZubiri, M. Hoffmann, D. W. Mac Donald, edit ors. Canids: Foxes, Wolves, Jackals and Dogs. Status Survey and Conservation Ac tion Plan. Cambridge, UK: IUCN/SSC Canid Specialist Group. Available online at: http://www.canids.org/species/Kit_fox.pdf (Accessed on April 4, 2008).

Ralls, K. B. Cypher, and L.K. Spiegel. 2007. Social monogamy in kit foxes: formation, association, duration, and disso lution of mated pairs. Jo urnal of Mammalogy 88(6):1439-

1011 1446. Available online at: http://www.bioone.org/arch ive/1545-1542/88/6/pdf/i1545- 1542-88-6-1439.pdf (Accessed on April 3, 2008).

Ridgley, H. 2007. Foxy City. Defenders Maga zine. Defenders of Wildlife. Available

online at: http://www.defenders.org/newsroom/defenders_magazine/fall_2007/foxy_city.php (Accessed on April 3, 2008).

San Joaquin County Multi-Species Habitat C onservation and Open Space Plan (SJCOG)

Available online at: http://www.sjcog.org/Programs%20&%20Project s/Habitat_files/Sp ecies/San%20Joaquin %20Kit%20Fox.pdf (Accessed on April 3, 2008)

U.S. Fish and Wildlife Service (USFWS). 1967. Native Fish and Wildlife, Endangered Species. Washington, D.C. Available online at: http://ecos.fws.gov/docs/ federal_register/fr18.pdf (Accessed on April 16, 2008).

U.S. Fish and Wildlife Service (USFWS). 1998. Recovery Plan for Upland Species of the San Joaquin Valley, California. U.S. Fi sh and Wildlife Service, Portland, Oregon. 319 pages. Available online at: http://ecos.fws.gov/docs/re covery_plans/1998/980930a.pdf (Accessed on March 31, 2008).

U.S. Fish and Wildlife Service (USFWS). 2008. Species Account: San Joaquin Kit Fox ( Vulpes macrotis mutica ). Sacramento Fish and Wildlif e Office. Available online at: http://www.fws.gov/sacramento/e s/animal_spp_acct/sj_kit_fox.htm (Accessed on March 31, 2008).

White, P. J., W. H. Berry, J. J. Eliason, and M. T. Hanson. 2000. Catastrophic decrease in an isolated population of kit foxes. Southwestern Naturalist 45(2):204–211. (Only the

abstract was viewed and us ed). Available online at: http://www.jstor.org/pss/3672462 (Accessed on April 3, 2008).