Black-footed Ferret (Mustela nigripes) is a medium-sized (0.56 m) weasel that was historically widely distributed across the Great Plains of the U.S. and Canada before being considered extinct in the wild. The ferret has been reintroduced to at least 21 sites. Sites in the following states/provinces were considered to have breeding adults: Arizona, Chihuahua, Colorado, Kansas, Montana, New Mexico, South Dakota, Utah, and Wyoming. They inhabit open grasslands, steppe, and shrub steppe where there are prairie dogs. Prairie dogs comprise about 90% of their diet.