Black-Footed Ferret(Mustela Nigripes) There is only one species of ferret native to the United States: the black-footed ferret. The black-footed ferret is one of the worlds rarest and most endangered mammals, listed in both the International Union for Conservation of Nature (IUCN) Red List and the United States Federal List. This species originally ranged through out the interior regions of North America, spanning from southern Canada to northern Mexico; today the black-footed ferrets are slowly being reintroduced in the wild. As of 2015 these ferrets have been released at 24 sites across eight states, Canada, and Mexico. It is a medium sized member of the weasel family, weighing 1.4 to 2.5 pounds, measuring 19 to 24 inches in length, and…show more content… After a gestation period of 41 to 43 days, a litter of three to six kits are born blind and helpless. At birth black-footed ferret kits are highly dependent on their mothers. Without assistance from the males, mothers raise their young. They remain below ground until around two months, roughly 42 days, of age; this is when the mother ferret begins to move them from burrow to burrow and teach them how to hunt. At approximately 90 days, the kits are at 90% of their adult body size. When fall arrives, the mothers separate from the kits as they reach their independence. By 365 days of age, both male and female kits are fully grown and sexually mature. The male black-footed ferret is slightly larger that the female. During mating season females aggressively solicit males. These ferrets exhibit delayed implantation where the fertilized egg does not start developing until conditions are appropriate for…show more content… The extreme dependence of this species on prairie dogs made it especially vulnerable to extinction. Prairie dogs were considered agricultural pests during most of the 20th century. Prairie dog populations rapidly declined due to extermination, canine distemper, and the plague. “The black-footed ferret captive breeding program was initiated in October 1985 by the Wyoming Game and Fish Department in cooperation with the United States Fish and Wildlife Service.” “Beginning in 1991, ferrets have been reintroduced at sites in eight Western U.S. states (Montana, South Dakota, Wyoming, Colorado, Utah, Arizona, Kansas, and New Mexico) and one site in Mexico (Bard, 2002; Bronson et al., 2007).” “There are currently six institutions (one federal facility and five zoos) participating in the propagation program under the supervision of the United States Fish and Wildlife Service.” (IUCN Red List,