Swift Fox
The swift fox is the eastern plains counterpart to the kit fox.
About This Species
The swift fox is generally nocturnal, with daytime activities restricted to the den site (Egoscue 1979). Kilgore (1969) observed swift fox basking in the sun midday during the winter months and morning, late afternoon and early evening during the summer. The swift fox is generally “naive” as evidenced by its ready acceptance of poison baits (Bunker 1940), willingness to den near human settlements (Cutter 1958) and trapping ease (Bailey 1926). The swift fox does not appear to exhibit any signs of territoriality (Kahn et al. 1997) as home ranges often overlap. Home ranges are often variable in size and in Colorado have been estimated to be 86 to 210 ha (Rongstad et al. 1989).
Protecting the Swift Fox
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Physical Characteristics
An adult swift fox typically weighs between two and three kg and is approximately 30 cm tall and 80 cm long. The swift fox is light gray to buff tan above with pale yellow to white coloring on its legs, sides and lower surface of the tail. The pelage (fur) color may be more orange during the summer months. The swift fox also has easily distinguishable black patches on either side of the snout and on the tip of the tail. The dental formula for the swift fox is: 3/3; 1/1; 4/4; 2/3; for a total of 42 teeth.
Range
The swift fox is native to the shortgrass and midgrass prairie ecosystems of the Great Plains region of North America. Historically, its range was believed to be as large as 1.6 million km2, and extended north to south from central Alberta to central Texas and east to west from western Iowa and Minnesota to central Colorado. A dramatic reduction in the range of the swift fox occurred in the early 1800s to the mid 1900s due to human settlement, land-use conversion of prairies, predator control campaigns, unregulated trapping, hunting and rodent control programs.
Habitat
Of all of the native North American foxes, the swift fox is the most “den-dependent”, using dens year-round and life-long for such purposes as predator evasion, protection against inclement weather, and raising young. Typically excavating its own den, the swift fox may also utilize and enhance burrows made by other species such as badgers, ground squirrels and prairie dogs. The swift fox dens are typically identified by a circular or slightly oval entrance approximately 17.5-22.5 cm in diameter with a dirt ramp leading from the entrance that may face any direction. Dens may have multiple openings and many dens may be used at any one time or throughout the year. Dens are excavated in a number of different habitats including native shortgrass prairie, pastures, roadside ditches, fencerows, fallow fields and even cultivated fields.
The swift fox very often chooses den sites close to roads. It is believed that roads are not only travel corridors for swift fox, but may also provide increased opportunity for hunting and foraging. Carrion along roads may be a very important food source. In addition, the area along roadways is often higher in small mammal abundance as compared to surrounding grasslands. A significant amount of swift fox mortality, however, may occur along roads. This may be due either to collisions with vehicles or coyote predation, as coyotes commonly use roads as travel corridors. Dens are typically located in shortgrass and midgrass prairie habitats. However, the swift fox will also occupy cropland habitats, pinon-juniper habitats in Colorado and Oklahoma, and the sandhills of Nebraska. Den sites are generally found on relatively flat areas; however, they may not necessarily be selecting for any particular slope as habitat is already characterized as level to gently rolling topography. Dens not only provide for swift fox needs, but can also provide cover for a number of other species of wildlife. Numerous invertebrates as well as the Great Plains toad (Bufo cognatus), a prairie rattlesnake (Crotalus viridis) and deer mice living in abandoned dens. The Burrowing Owl (Speotyto cunicularia) and striped skunk (Mephitis mephitis) are also commonly found in abandoned dens.
Diet
The swift fox feeds opportunistically on a wide variety of small mammals, birds, reptiles, insects,
plants and carrion.
Reproduction
The swift fox typically lives in family groups of one male and two females. It is monestrous and monogamous and apparently forms long-term pair bonds, breeding only once a year. In Colorado, breeding generally occurs during late December to early January with a gestation period of approximately 50 days resulting in pups being born in March to early April. A litter is typically three to six pups. Pups are altricial at birth with eyes and ears remaining closed for 10-15 days. Pups remain below ground for approximately one month and are weaned at about six to seven weeks of age. The young occupy a separate den, but remain with the parents until August or September of their first year.