DESCRIPTION: This small fox is about the size of a large housecat. It is 27-34 inches (69-86 cm) long and weighs 4-6 pounds (1.8-2.7 kg). It has a pale buff back and a white underside. Other characteristics include its large triangular ears, dark spots on the muzzle below the eyes and a black-tipped, bushy tail. It gets its name from the ability to reach speeds of up to 40 km per hour.
STATUS: Federal Candidate, State Threatened
REASONS FOR CURRENT STATUS: The reasons for the disappearance of the swift fox is uncertain, but poisoning, intensive trapping and habitat destruction are thought to be the main causes.
REPRODUCTION AND DEVELOPMENT: Male swift fox breed at one year; females may wait until their second year. Swift fox breed in early spring, producing 2-6 pups 50-60 days later. Pups are born underground and emerge from the den after 1 month and are weaned at 6-7 weeks. The pup's eyes and ears remain closed for 10-15 days after birth. Parents may move pups several times during the rearing period. Pups disperse from the natal area during late summer or fall. Swift fox live 3 to 6 years in the wild, but can live up to 14 years in captivity.
The swift fox is an opportunistic feeder on small mammals (prairie dogs, jackrabbits, ground squirrels), birds, insects (especially grasshoppers and crickets), berries, vegetation and carrion. Scavenging for roadkills may contribute to the number of swift fox killed by vehicles.
RANGE: This species was once abundant throughout much of the North American prairie. It is currently found in eastern New Mexico, eastern and northern Colorado, parts of Wyoming and Montana, northwestern Texas, western Kansas, the Panhandle of Oklahoma and western Nebraska, South Dakota, North Dakota and reintroduced into Canada. The swift fox was historically found statewide in South Dakota. There are few recent reports, most of which originate from the southwestern quarter of the state.
POPULATION LEVEL: Unknown
HABITAT: The swift fox inhabits open prairies, plains and shrubby desert areas away from extensively cultivated land. It is usually found in areas with gently rolling hills or undulating topography. In South Dakota, swift fox prefer short to midgrass prairies.
Unlike coyotes and other foxes, swift fox use den sites year-round. It may excavate its own den in sandy loam soil, usually on or near hilltops in moderate to heavily grazed short or midgrass prairie. Dens might also be dug in a sandy stream valley or along a fencerow. Swift fox may also occupy abandoned badger dens or prairie dog burrows. Usually a nocturnal hunter, the swift fox is sometimes observed at dawn or dusk or during the day near its den entrance.
MANAGEMENT AND PROTECTION: The swift fox is a candidate for federal listing, reflecting its declining abundance. Agricultural practices, as well as recent recurring drought in the Midwest, have reduced habitat and prey abundance. The swift fox is easily trapped and readily takes poison bait intended for coyotes and red fox. Captive breeding has been successful in Canada and may be a useful recovery technique in other areas.
Protection in South Dakota has included listing as a state threatened species, transplant programs and den site secrecy. It is apparent that more intensive monitoring and management will be necessary to recover this species to a secure population level. Appreciation and management of the prairie dog ecosystem, with its many interdependent components, will undoubtedly aid swift fox recovery efforts.
Information obtained from the Northern Prairie Wildlife Research Center
Animal Diversity Web by University of Michigan
Doug Stewart, "Caught in a Dog Fight", National Wildlife Federation, June/July 1999.