Vulpes macrotis mutica

Vulpes macrotis mutica

San Joaquin kit fox
FWS Focus

Overview

The San Joaquin kit fox (Vulpes macrotis mutica) is the smallest fox in North America, with an average body length of 20 inches and weight of about 5 pounds. It is a member of the Canidae family, which includes dogs, wolves and foxes. San Joaquin kit foxes are lightly built, with long legs and large ears. Their coat ranges from tan to buffy gray in the summer to silvery gray in the winter. Their belly is whitish and their tail is black-tipped.
Characteristics
Overview

The San Joaquin kit fox is small, tan fox with a bushy, black-tipped tail. The fox only weighs about 5 pounds when fully grown. It has a narrow nose and a small, slim body. The foot pads of kit foxes are small by comparison with other canids. The fox is specially adapted for its desert habitat. Its large, close-set ears help dissipate heat, keeping it cool in the hot desert.

It was listed as endangered on March 11, 1967.

The San Joaquin kit fox roams throughout much of the valley floor and foothills of the San Joaquin Valley in California, from San Joaquin County in the north to Kern County in the south. The kit fox’s range also includes valleys along the Coast Range, including the Panoche and Cuyama valleys and the Carrizo Plain in San Luis Obispo County.

The San Joaquin kit fox faces a number of threats that lead to direct mortalities, displacement, reduction of prey populations and denning sites, and increased competition with other predators. Those threats include: 

  • Loss of habitat due to conversion of land to agriculture, oil exploration and spills, urban and solar facility development and infrastructure construction
  • Diseases including rabies, canine parvovirus, mange and canine distemper virus
  • Wildfire
  • Predation and competition from coyotes, red foxes and domestic dogs

Scientific Name

Vulpes macrotis mutica
Common Name
San Joaquin kit fox
FWS Category
Mammals

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Food

Characteristics
Food

The San Joaquin kit fox is an opportunistic hunter. Its primary food is kangaroo rats, but it also actively hunts white-footed mice, pocket mice, ground squirrels, rabbits and ground-nesting birds. During certain times of the year, kit foxes will also eat insects.

Characteristic category

Behavior

Characteristics
Behavior

The San Joaquin kit fox is nocturnal, hunting at night and resting most of the day in their dens. The dens help the fox escape the desert heat and provide shelter and cover from predators. Kit foxes either dig their own dens, use those constructed by other animals, or use human-made structures such as culverts, abandoned pipelines, or banks in sumps or roadbeds.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The San Joaquin kit fox is small, tan fox with a bushy, black-tipped tail. The fox only weighs about 5 pounds when full grown. It has a narrow nose and a small, slim body. The foot pads of kit foxes are small by comparison with other canids.

The fox is specially adapted for its desert habitat. Its large, close-set ears help dissipate heat, keeping it cool in the hot desert.

Size:

  • Height: 12 inches (30 cm) tall at the shoulder
Weight
  • Weight: Males weigh approximately 5 pounds (2.3 kiligrams); Females weigh approximately 4.6 pounds (2.1 kilograms)
Characteristic category

Lifecycle

Characteristics
Reproduction

Kit foxes start breeding when they’re 1 year old. In the fall, females begin to clean and enlarge their pupping dens. The foxes mate between December and March. Females give birth to two to six pups in February or March. Pups stay inside the den for the first month of their lives. Both males and females care for the pups, and adult pairs stay together for the entire year.

Lifespan

The San Joaquin kit fox lives to be about 7 years old.

Characteristic category

Similar Species

Characteristics
Similar Species
Characteristic category

Habitat

Characteristics
Habitat

The San Joaquin kit fox lives in the desert and grasslands of California’s San Joaquin Valley. They prefer areas with minimal shrubs and grasses.

The San Joaquin kit fox historically roamed throughout much of the San Joaquin Valley in California, from San Joaquin County in the north to Kern County in the south. By 1930, kit fox range had been reduced by more than half, with the largest portion of the range remaining in the southern and western parts of the valley.

The kit fox’s range in the San Joaquin Valley extends from southern Kern County north to Contra Costa, Alameda, and San Joaquin counties on the western side of the valley; and to the La Grange area of Stanislaus County on the eastern side of the valley. The kit fox’s range also includes valleys along the Coast Range including the Panoche and Cuyama valleys and the Carrizo Plain in San Luis Obispo County.

Grassland

Land on which the natural dominant plant forms are grasses and forbs.

Desert

Arid land with usually sparse vegetation.

Geography

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Timeline

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