Blackfooted ferrets were declared extinct in the wild in the late 1980s but are now on the rise again after being reintroduced from captive stock.

The reintroduction, led by the US Fish and Wildlife Service, began in 1991, and in spring this year 500 breeding adult blackfooted ferrets were counted in the wild, with a further 300 in captivity.

The ferret, Mustela nigripes, had been driven out because its favourite prey, the prairie dog, was suffering a severe decline. Ranchers in the US hated the prairie dog because it built burrows into which cattle and horses stumbled, breaking their legs. Persecution, disease and change of land use - so that the prairie was turned into crops - reduced prairie dog numbers, which in turn devastated the ferrets.

Jan Schipper, of the IUCN, said that the recovery of the ferret was a “classic textbook example” of conservation that turned what was regarded by conservationists as a tragedy into a success story. The combination of an organised captive breeding programme combined with habitat conservation, to ensure the animal had somewhere it could live in relative safety, has offered the creature a future on the prairies. It is now present in eight US states. From being classified as extinct in the wild the blackfooted ferret is now described as endangered.

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