Black-footed Ferret

The black-footed ferret has a long, slender body with black outlines on its paws, ears, parts of its face and its tail. The forehead is arched and broad, and the muzzle is short. It has few whiskers, and its ears are triangular, short, erect and broad at the base. The neck is long and the legs short and stout. The toes are armed with sharp, very slightly arched claws. The feet on both surfaces are covered in hair, even to the soles, thus concealing the claws. It combines several physical features common in both members of the subgenus Gale (least and short-tailed weasels) and Putorius (European and steppe polecats). Its skull resembles that of polecats in its size, massiveness and the development of its ridges and depressions, though it is distinguished by the extreme degree of constriction behind the orbits where the width of the cranium is much less than that of the muzzle. Although similar in size to polecats, its attenuate body, long neck, very short legs, slim tail, large orbicular ears and close-set pelage is much closer in conformation to weasels and stoats. The dentition of the black-footed ferret closely resembles that of the European and steppe polecat, though the back lower molar is vestigial, with a hemispherical crown which is too small and weak to develop the little cusps which are more apparent in polecats. …

The historical range of the black-footed ferret was closely correlated with, but not restricted to, the range of prairie dogs (Cynomys spp.). Its range extended from southern Alberta and southern Saskatchewan south to Texas, New Mexico, and Arizona. As of 2007, the only known wild black-footed ferret population was located on approximately 6,000 acres (2,400 hectares) in the western Big Horn Basin near Meeteetse, Wyoming. Since 1990, black-footed ferrets have been reintroduced to the following sites: Shirley Basin, Wyoming; UL Bend National Wildlife Refuge and Fort Belknap Indian Reservation, Montana; Conata Basin/Badlands, Buffalo Gap National Grassland, Wind Cave National Park and the Cheyenne River Sioux Reservation in South Dakota; Aubrey Valley, Arizona; Rocky Mountain Arsenal National Wildlife Refuge and Wolf Creek in Colorado; Coyote Basin, straddling Colorado and Utah, northern Chihuahua, Mexico, and Grasslands National Park, Canada. Historical habitats of the black-footed ferret included shortgrass prairie, mixed-grass prairie, desert grassland, shrub steppe, sagebrush steppe, mountain grassland, and semi-arid grassland. Black-footed ferrets use prairie dog burrows for raising young, avoiding predators, and thermal cover. …

The black-footed ferret is solitary, except when breeding or raising litters. It is nocturnal and primarily hunts for sleeping prairie dogs in their burrows. It is most active above ground from dusk to midnight and 4 am to mid-morning. Aboveground activity is greatest during late summer and early autumn when juveniles become independent. Climate generally does not limit black-footed ferret activity, but it may remain inactive inside burrows for up to 6 days at a time during winter. Female black-footed ferrets have smaller home ranges than males. Home ranges of males may sometimes include the home ranges of several females. Adult females usually occupy the same territory every year. A female that was tracked from December to March occupied 39.5 acres (16 ha). Her territory was overlapped by a resident male that occupied 337.5 acres (137 ha) during the same period. The average density of black-footed ferrets near Meeteetse, Wyoming, is estimated at one black-footed ferret to 148 acres (60 ha). As of 1985, 40 to 60 black-footed ferrets occupied a total of 6,178 to 7,413 acres (2,500 to 3,000 ha) of white-tailed prairie dog habitat. From 1982 to 1984, the average year-round movement of 15 black-footed ferrets between white-tailed prairie dog colonies was 1.6 miles/night (2.5 km) (with a spread of 1.1 miles or 1.7 km). …

Native American tribes, including the Crow, Blackfoot, Sioux, Cheyenne, and Pawnee, used black-footed ferrets for religious rites and for food. The species was not encountered during the Lewis and Clark Expedition, nor was it seen by Nuttall or Townsend, and it did not become known to modern science until it was first described in John James Audubon and John Bachman's Viviparous Quadrupeds of North America in 1851.

It is with great pleasure that we introduce this handsome new species; ... [it] inhabits the wooded parts of the country to the Rocky Mountains, and perhaps is found beyond that range... When we consider the very rapid manner in which every expedition that has crossed the Rocky Mountains, has been pushed forward, we cannot wonder that many species have been entirely overlooked... The habits of this species resemble, as far as we have learned, those of [the European polecat]. It feeds on birds, small reptiles and animals, eggs, and various insects, and is a bold and cunning foe to the rabbits, hares, grouse, and other game of our western regions.

Decline. For a time, the black-footed ferret was harvested for the fur trade, with the American Fur Company having received 86 ferret skins from Pratt, Chouteau, and Company of St. Louis in the late 1830s. …