Mara (mammal)

The maras are a genus ("Dolichotis") of the cavy family of rodents. They are the sole extant representatives of the subfamily Dolichotinae. These large relatives of guinea pigs are common in the Patagonian steppes of Argentina, but also live in Paraguay and elsewhere in South America. Maras are the fourth-largest rodent in the world, after capybaras, beavers, and porcupines, reaching about in height.
Etymology.
"Dolichotis" means "long-eared" (from "long" and "ear") in Ancient Greek.
Description.
Maras have stocky bodies, three sharp-clawed digits on the hind feet, and four digits of the fore feet. Maras have been described as resembling long-legged rabbits. Patagonian maras can run at speeds up to . They can weigh over in adulthood.
Most maras have brown heads and bodies, dark (almost black) rumps with a white fringe around the base, and white bellies.
Maras may amble, hop in a rabbit-like fashion, gallop, or bounce on all fours. They have been known to leap up to .
Maras mate for life, and may have from one to three offspring each year. Mara young are very well-developed, and can start grazing within 24 hours. They use a crèche system, where one pair of adults keeps watch all the young in the crèche. If they spot danger, the young rush below ground into a burrow, and the adults are left to run for it.
Species.
Two extant and two extinct species of maras are recognized: 
Fossils are known from Argentina:
Interaction with humans.
Patagonian maras are often kept in zoos or as pets, and are also known as "Patagonian cavies" or "Patagonian hares". They can be quite social with humans if raised with human interaction from a young age, though they avoid people in the wild. Maras may even change their habits from coming out in day to becoming nocturnal, simply to avoid social interaction.