Zorritas—Little Foxes of the Desert

By Ron Harton

Just after sunset, I drove slowly down a dirt road that had cut a scar though the foothill grassland on the west side of the San Joaquin Valley. The orange glow of the sky bronzed the dry, brown grass. Suddenly, near the fence line, I saw what looked like a small tan dog with large ears dash out ahead of me and then vanish. I stopped my truck and looked around. I found nothing—no evidence, no tracks, just the grasses stretching for miles over the hills. I heard no sound, other than the hissing of the grass dancing in the wind.

The animal I saw that day might have been a kit fox, Vulpes macrotis, smallest of the American foxes, and one threatened or endangered in many areas of its range..Kit foxes make their homes in the desert and dry grasslands of the West, from Mexico to Canada. They are very small. A full grown adult weighs only five pounds, about the size of a large house cat. Their bodies are yellow-tan, with white and black highlights. Their tails are tan and grey with a black tip. Their ears are very large in proportion to their heads. In Spanish they are called zorritas—the little foxes, or Zorras de las praderas—foxes of the meadows or grasslands, denoting their frequency in dry grasslands and pastures. However, kit foxes survive in the driest parts of the desert by getting water from the bodies of the rodents they eat.

Kit foxes are extremely quick, earning them the nickname, "desert swifts." They are also very curious and adventurous. The old saying, "Curiosity killed the cat," might apply to these foxes. They have been known to gulp down poisoned food and to walk easily into traps. They rely on their sense of hearing to warn them of danger and to lead them to prey. They may not have a finely developed sense of smell. In research tests, the foxes have walked within ten feet of strongly aromatic food without noticing it.

Kit foxes are night hunters, coming out of their underground burrows just after sundown to stalk the rodents that form the staple of their diet. They eat ground squirrels, kangaroo rats, rabbits, mice, and other small mammals. They also eat insects, sparrows, horned larks, lizards, amphibians, and even grass. They are so fond of kangaroo rats, that in some areas those rodents are the main stay of their diet. Adult kit foxes need about six ounces of meat a night to survive. Sometimes kit foxes stalk their prey like cats—creeping up slowly and the pouncing. At other times they dig out the tunnels of squirrels, rats, and mice, pulling the animals from their burrows. They have been observed to plug up the escape holes of ground squirrels and then dig them out.

Kit foxes live in their dens the year round. Foxes form pairs during October and November. The litters of three to six pups are born in March or early April. They raise their family in large breeding dens. For the first month of their lives, the pups are nursed by their mother. The father hunts and brings the family food to the den. During the second month, both parents start hunting in order to feed the rapidly growing pups. The family unit stays together until autumn, when the pups leave home for adult lives of their own. The foxes establish individual territories of about two square miles.

There are several subspecies of kit foxes. Although they were once common throughout their range in the West, the kit fox is endangered in some areas. The San Joaquin Kit Fox, Vulpes macrotis mutica, is one of the endangered foxes. It lives in the dry grasslands of the Central Valley and such areas as the Carrizo Plains Natural Area.

The Carrizo Plains Natural Area is a good place to look for kit foxes. Located in western San Luis Obispo County, Carrizo Plains features a beautiful dry lake, Soda Lake, and several habitat types—juniper mixed scrubland, alkali desert scrub, and annual grassland. The natural area offers primitive camping, hiking trails, and backpacking opportunities. It is the site of the Caliente Mountain Proposed Wilderness in the Wildlands 2000 program. A visitor center there has an excellent display on kit foxes.

BIBLIOGRAPHY

Jaeger, Edmund C. Desert Wildlife. Stanford: Stanford University Press, 1961.

Kirk, Ruth. Desert: The American Southwest. Boston: Houghton Mifflin, 1973.

"Kit Fox." Wildlife Report: News from the Colorado Division of Wildlife. http://www.dnr.state.co.us/cdnr_news/wildlife/980316141835.html November 28, 1999.

Sutton, Ann and Myron. The Life of the Desert. New York: McGraw-Hill, 1966.

Tweit, Susan. Seasons in the Desert. San Francisco: Chronicle Books, 1998.

Zwinger, Ann. The Mysterious Lands. Tuscon: The University of Arizona Press, 1989.