Mara

A giant guinea pig

The mara (or Patagonian cavy) is the world’s fourth-largest rodent and the second-largest in South America after the capybara. Despite a striking resemblance to deer — with long legs, hoofed toes, upright ears, and a graceful running gait — it is firmly a rodent and closely related to guinea pigs. It can run at 45 km/h and bounds like a deer when alarmed.

Lifelong pair bonds

Maras form monogamous pair bonds that last for life — unusual among rodents. A male follows his female almost everywhere, guarding her from other males. Pairs separate only when feeding, regrouping frequently. The pair bond is maintained by constant proximity and shared scent marking. If a partner dies, the survivor often refuses to bond with a new partner.

Communal crèche

Multiple breeding pairs use a communal den (a large burrow) for raising young. Up to 15 females deposit their pups in the shared burrow, and pairs take turns guarding the entrance. When a female arrives to nurse, she calls her own young — the pups recognise their mother’s call and emerge to nurse. It is one of the most unusual communal care systems among mammals.

Running on tiptoe

Maras walk and run on the tips of their hoofed toes — a convergent adaptation with deer and antelopes that has evolved independently in this rodent. The forefeet have three digits with claw-like hooves; the hind feet have four digits. This digitigrade posture gives them the speed to escape predators across open steppe.