THE SAN JOAQUIN KIT FOX

Subspecific designations for the species are not fully addressed. As many as eight subspecies have been recognized, although further analyzes have not found support for any subspecies differentiation. However, although there is a clear need for more subspecific clarification, most available data suggest that kit foxes in the San Joaquin Valley of California are likely to warrant a subspecific designation, Vulpes macrotis mutica, due to geographical isolation, and that any other kit foxes may be included in a second subspecies, Vulpes macrotis macrotis.

The endangered San Joaquin kit fox was formerly very common in the San Joaquin Valley and through much of Central California. Its 1990 population was estimated to be 7,000. This subspecies is still endangered, after nearly 50 years of being on the Endangered Species List. Officially, this subspecies was listed March 3, 1967. On September 26, 2007, Wildlands Inc. announced the designation of the 684 acre (277 ha) Deadman Creek Conservation Bank, which is intended specifically to protect habitat of the San Joaquin kit fox. However, the population continues to decline mostly due to heavy habitat loss. Other factors include competition from red foxes and the extermination of the wolf from California, which has left the coyote as the dominant meso-predator in kit fox territory, bringing an imbalance in ecosystem relationships.

About the species

A small-sized Fox, with small, slim body and long slender legs, and large ears. The largest subspecies of both Kit Fox. Coat coloration is generally tan in the summer and silver gray in the winter. Guard hairs on the back are black tipped, which accounts for the grizzled appearance. Underparts are light buff to white, with the shoulders, lower sides, flanks and chest buff to a rust color. Relatively large ears, set close together, dark on the back side, with a thick border of white hairs on the forward-inner edge and inner base. Narrow muzzle. Tail is long and bushy, tapering slightly toward the tip, typically carried low and straight, black tipped. Females are slightly smaller than males.

Reproduction and behavior

Gestation: 48-52 days.
Young per birth: 2-6.
Weaning: around 90 days.
Sexual maturity: 12 months.
Life span: 8 years, 10 years in captivity.
Breeding season: December to March.

Litters are born in February and March. During this period the males provides most of the food for the females and the pups. Pups emerge above ground at 1 month of age. After 4 to 5 months the family bonds begin to dissolve and the young begin dispersing. Offspring of both sexes sometimes remain with their parents through the following year and help raise a subsequent litter.

They use dens for shelter, reproduction and escape from predators; numerous dens may be used throughout the year. They either construct dens by digging or use existing dens and structures created by other animals, such as ground squirrels, badgers, and Coyotes, or human-made structures. Entrances are usually from 20 to 25 cm in diameter, normally higher than wide. Social behavior: Mated pairs year-round; monogamous.

Diet and interaction with the environment

The diet varies regionally and seasonally, according to the availability of prey, and includes kangaroo rats, pocket mice, white-footed mice, other nocturnal rodents, California ground squirrels, black tailed hares, San Joaquin antelope squirrels, desert cottontails, ground-nesting birds, chukars and insects. Their main predators are the Coyote, Red Fox, Domestic Dog, bobcat and large raptors.

These foxes are nocturnal, typically hunting at night, although may hunt during daylight hours when necessary, as illustrated by their consumption of the diurnal

ground squirrel. Home ranges from 2.6 to 31 km2.

Habitat:

Native to United States. It currently inhabits certain regions of the San Joaquin Valley floor and the surrounding foothills, from South Kern County to Contra Costa, in California. Three core Kit Fox populations are found in the Carrizo Plain, Western Kern County, and the Ciervo Panoche Natural Area.

Their habitat consists in grasslands and shrublands, many of which have been extensively modified. They may also inhabit oak woodland, alkali sink shrubland, and vernal pool and alkali meadow communities. The conservation status is Endangered (USA), Threatened (California). Historically abundant in the San Joaquin Valley and surrounding areas, but their populations have been reduced as a result of urban and agricultural development, oil and gas development, as well as predator and rodent control programs. Carrizo Plain has the largest population, with an estimated 250 to 600 individuals. Habitat destruction is the greatest threat. Expansion of Red Foxes may be a factor in the apparent decline in the northwestern segment of their range.