The black-footed ferret (Mustela nigripes), also known as the American polecat or prairie dog hunter, is a species of mustelid native to central North America. It is listed as endangered by the IUCN, because of its very small and restricted populations. First discovered by Audubon and Bachman in 1851, the species declined throughout the 20th century, primarily as a result of decreases in prairie dog populations and sylvatic plague. It was declared extinct in 1979 until Lucille Hogg's dog brought a dead black-footed ferret to her door in Meeteetse, Wyoming in 1981. That remnant population of a few dozen ferrets lasted there until the animals were considered extinct in the wild in 1987. However, a captive breeding program launched by the United States Fish and Wildlife Service resulted in its reintroduction into eight western states and Mexico from 1991 to 2008. There are now over 1,000 mature, wild-born individuals in the wild across 18 populations, with five self-sustaining populations in South Dakota (two), Arizona, Wyoming and Saskatchewan. It was first listed as 'Endangered' in 1982, then listed as 'Extinct in the Wild' in 1996 before being downgraded back to 'Endangered' in 2008.