A member of the Mustelidae (weasel) family, the black-footed ferret (Mustela nigripes) is the only ferret native to North America. It has pale yellow fur, an off-white throat and belly, a dark face, black feet, and a black tail. The black-footed ferret usually grows to a length of 18 in (46 cm) and weighs 1.5–3 lb (0.68–1.4 kg), though the males are larger than the females. These ferrets have short legs and slender bodies, and lope along by placing both front feet on the ground followed by both back feet.

Ferrets live in prairie dog burrows and feed primarily upon prairie dogs, mice, squirrels, and gophers, as well as small rabbits and carrion. Ferrets are nocturnal animals; activity outside the burrow occurs after sunset until about two hours before sunrise. They do not hibernate and remain active all year long.

Breeding takes place once a year, in March or early...