Order Carnivora – Meat eating mammals
Family Mustelidae – weasels, badgers, skunks, and otters
Scientific Name: Mustela nigripes
Description: Length is 20-24 inches including a 5-6 inch tail. Weighs up to 2 ½ pounds with males being slightly larger than females. Body is long and narrow with short legs. Ears are prominent. The color is normally a yellow-buff but is paler on the underparts. The forehead, muzzle, and throat are nearly white; top of head and middle of back are brown; face mask, feet, and tip of tail are black.
Home Range: Historically was prevalent in North American
prairies from Southern Saskatchewan to Northern Mexico and
east from the foothills of the Rocky Mountains including much of
Texas, Oklahoma, Kansas, Nebraska, and the Dakotas. Now only
present in the wild in select reintroduction sites.
Habitat Type: Lives exclusively in prairie dog burrows
of the short grass prairie.
Reproductive Habits: Black footed ferrets are solitary except during the mating season which is usually March - April. They reproduce only once a year, and a litter of 1-5 young are born after a gestation period of 42 - 45 days. The young, called kits, begin to venture out of the burrow in early July, and are ready to leave their mother by early October. While males will disperse great distances, females tend to stay close to their mother’s burrow. Black footed ferrets reach sexual maturity at one year of age; however, some males which attempt mating cannot actually mate until late in their first season.
Because females do not ovulate until they have mated, scientists in charge of the captive breeding programs have developed methods to determine optimum breeding condition in both males and females. In order to promote as much genetic diversity as possible, Artificial Insemination (AI) has become common at the various breeding facilities.
Diet in Wild: 90% of diet is prairie dogs. Some additional small mammals.
Diet in Zoo: Bird of Prey meat, thawed mouse once a week.
General Info: Black footed ferrets are probably the rarest mammal in North America. They may have once been common in the American West, but by the early 1900’s settlers had begun a campaign to eradicate the ferret’s main source of food—the prairie dog. Because these ferrets rely on prairie dogs for 90% of their food and use the prairie dogs’ burrows for shelter, their numbers declined dramatically with the prairie dog. It is now estimated that 98% of prairie dog habitat has been destroyed. Although large colonies still remain, they are isolated from each other so that colonization has become impossible.
Black footed ferrets were listed as endangered in 1967 and feared extinct by the mid 1970s. In 1981, a colony was discovered near Meeteetse, WY. Unfortunately, an outbreak of sylvatic plague and canine distemper began to decimate the colony. The last 18 ferrets known to exist were captured and placed in an intensive captive breeding program. Release sites have now been established in four states: Shirley Basin, WY; Badlands National Park, SD; Aubrey Valley, AZ; and Charles M. Russell National Wildlife Refuge, MT. The next release site will be in Northwestern Colorado (Fall 1999).
Prairie dog numbers continue to decline as many local and state laws require land owners to eradicate prairie dogs on their property. As long as the prairie dog numbers continue to decline, there will not be enough habitat to downlist the Black footed ferret to threatened. Although land owners may consider prairie dogs pests, they are actually a keystone prairie species. Animals such as the swift fox, burrowing owl, and many others, rely on prairie dog towns for their survival. In addition, prairie dogs loosen and aerate the soil and their grazing activities reduce perennial grasses and encourage plant diversity. This diverse plant composition is generally more nutritious for cattle, and promotes faster weight gain. Because cattle prefer the improved grasses that result from prairie dog activities, they graze prairie dog towns harder and as a result, the towns become overgrazed. The prairie dogs do not overgraze, but they may be attracted to overgrazed areas because the shorter grasses provide a better view of approaching predators.
Predators: Owls, hawks, eagles, coyotes, bobcats.
Black footed ferrets are listed in CITES Appendix I and IUCN Red List as Endangered.
Black Footed Ferret: Return of a Native. 1998. Pamphlet. U.S. Fish and Wildlife Service.
Black Footed Ferret Slide Show. 1999. Dawn Olson. Kathy Sexson, Ed.
Walker’s Mammals of the World, Vol II. Fifth Edition. 1991. Ronald M. Nowak. Johns Hopkins University Press. Baltimore. pp. 1104-1105, 1113-1114.