Swift Fox

Appearance

The swift fox has a dark, grayish, tan coloration that extends to a yellowish tan color across its sides and legs. The throat, chest, and belly range from pale yellow to white in color. Its tail is black-tipped, and it has black patches on its muzzle. Its ears are noticeably large, like those of the kit fox, although slightly farther apart than on the head of the latter. It is about 12 inches in height, and 31 inches long, measuring from the head to the tip of the tail, or about the size of a domestic cat. Its weight ranges from around five to seven pounds. Males and females are similar in appearance, although males are slightly larger.

Naming

It is closely related to the kit fox and some mammalogists classify them as conspecific. However, molecular systematics imply that the two species are distinct. Interbreeding between the two species does occur where their ranges overlap, but this hybridization is quite restricted in scope.

Distribution

The swift fox lives in short-grass prairies and western grassland. They form their dens in sandy soil on open prairies, in plowed fields, or along fences. It is native to the Great Plains region of North America, and its range extends north to the southern Alberta and Saskatchewan, Canada, and south to Texas. It reaches from western Iowa to Colorado, Kansas, Wyoming, Nebraska, and Montana.

Reproduction

Swift foxes are a socially monogamous species, although multiple breeding strategies have been observed. The adult swift fox's breeding season varies with region. In the southern United States, it mates between December and February with pups born in March and early April, while in Canada, the breeding season begins in March, and pups are born in mid-May. The male swift fox matures and may mate at one year, while the female usually waits until her second year before breeding. Adults live in pairs, and although some individuals mate for life, others choose different partners each year. Gestation takes around 51 days, and four to five kits are born.

The swift fox only has one litter annually, but may occupy up to thirteen dens in one year, moving because prey is scarce or because skin parasites build up inside the den. Sometimes it makes other burrows from other bigger animals, even though it is completely capable of digging one on its own. Pups are born in the den and typically remain there for approximately one month. A newborn pup's eyes and ears remain closed for ten to fifteen days, leaving it dependent on the mother for food and protection during this time. It is usually weaned around six or seven weeks old and remains with its parents until fall. Recent research has shown that social organization in the swift fox is unusual among canids, since it is based on the females. Females maintain territories at all times, but males emigrate if the resident female is killed or removed.

Food

Like most foxes, the swift fox is an omnivore. Rabbits, mice, ground squirrels, birds, insects, other arthropods, lizards, amphibians, fish and eggs are staples. Grasses and fruits round out its diet. However, like any efficient forager, the swift fox takes advantage of seasonal foods. During the summer, adults eat large amounts of insects, including beetles and grasshoppers, and feed their young with larger prey items. Deer and other carrion killed by other animals may also be important food sources.