Black-tailed prairie dog

The black-tailed prairie dog (Cynomys ludovicianus) is named for its preferred habitat as well as for the fact that it emits an alarm cry resembling a canine bark, which they also emit during their hierarchical fights. In fact, their genus classification, Cynomys, means ‘rodent dog’ in Greek. There are five species of prairie dogs, all native to North America, of which only the black-tailed and Mexican prairie dogs have this characteristic colouring on the tip of the tail, the other three species being white. The size of the molars and social vocalisations also differ between species.

Its stout body and short legs, as well as its tail, give the prairie dog a different appearance from that of the marmots, to which it is related. Its coat is greyish-brown, slightly darker on top and lighter on the belly. It has a very good sense of hearing and sight, despite its small ears and eyes, which are dark in colour to withstand the intense sunlight. It also has long, strong nails which it uses to dig in the ground and the burrows in which it lives, as well as to get its roots or pull up the grass or forage on which it feeds, supplementing its diet with insects, worms, eggs, etc.

Diurnal, the prairie dog spends the night in the caves or burrows it digs, which are hundreds of metres long and have tunnels between 10 and 15 cm wide in which nothing is lacking: the excavated soil accumulates at the entrance to prevent possible flooding, the surrounding plants are kept short to improve visibility, the nests are lined with grass and are between one and five metres deep to keep them safe from predators, they have several entrances and emergency exits as well as latrines, a food pantry and sleeping areas. In any case, the black-tailed prairie dog does not hibernate, unlike other species.

It lives in large colonies of hundreds of individuals, which are divided into family units of up to 25 members, consisting of a male, several females and a large number of young offspring, although cases have been documented of two males, usually brothers. While the females in each unit always remain in the unit, and are therefore related to each other, the males leave the colony in the second year of life to try to take control of another colony. There is no shared breeding, but each female takes care of her own litter of between three and seven offspring, with females attacking other offspring and causing high mortality, resulting in the survival of the offspring of the strongest female as an advantage in natural selection; this behaviour is unique among mammals.

Each family unit reinforces its social bonds through close contact, either by cleaning, sniffing or petting each other. In addition, the prairie dog communicates through a sophisticated system of calls reinforced by body posture, and up to eleven different types of this form of communication have been identified and their name is associated with it.