Black-Tailed Prairie Dogs (Cynomys ludovicianus) are the largest of the five species of prairie dogs, a genus of rodents found in dry, open, flat areas of North America. They live in very large colonies, which are comprised of smaller social groups known as coteries, each made up of one (or occasionally multiple) male and multiple related females. Prairie Dogs form 90% of the diet of the endangered Black-Footed Ferret (Mustela nigripes). (x, x, x)