The black-footed ferret is endangered because the main source of its diet, prairie dogs, is in decline due to habitat loss. A black-footed ferret colony needs at least 10,000 acres of prairie dog colonies in order to survive. As prairie is converted to farmland, the prairie dog population declines, which takes the ferret population with it.
In 1986, only 18 black-footed ferrets were left in the wild, and captive breeding programs kept this animal from extinction. The ferret has been slowly reintroduced to the wild, but successful reintroduction requires at least 20,000 acres of prairie dog colonies. The ferret ranges throughout more than 20 locations in the United States, Mexico and Canada with a wild population of 500 as of 2013.
The black-footed ferret is a nocturnal animal that lives the majority of its life underground. It eats, sleeps and mates in its burrow, leaving only to hunt prairie dogs. When the ferret reproduces, the female has a litter size between three and four kits. The kits remain underground for the first several weeks of their lives. Once they turn 2 months old, they accompany their mother on hunting expeditions. At this point, the kits live in separate burrows. By the time the kits reach 5 months old, they are completely independent.