Patagonian Mara

About the Patagonian mara

The Patagonian mara looks like a cross between a jackrabbit and a small deer, and that resemblance is more than skin deep. It's actually a rodent, a member of the mara genus Dolichotis and a relative of guinea pigs and capybaras in the caviid family, but its build has converged on something closer to a small ungulate: distinctive upright ears, long limbs, and hind legs that are noticeably longer and more muscular than its front legs. Its feet are compressed into hoof-like pads — four digits in front, three behind — and its tail is short, flattened, and hairless. The coat is gray on top with a white rump patch set off by a black band, a white underside, and a somewhat orange flank and chin. A typical adult runs 69 to 75 cm (27 to 30 in) in head-and-body length, with a 4 to 5 cm (1.6 to 2.0 in) tail, and weighs 8 to 16 kg (18 to 35 lb). One anatomical quirk separates it from most other caviids: its anal glands sit between the anus and the base of the tail rather than in front of the anus.

Maras are found only in Argentina, between roughly 28° and 50° south latitude, which takes in much of Patagonia. They favor habitat with shrub cover but also turn up on overgrazed and barren ground in the Monte Desert biome; in northwestern Argentina they lean toward lowland forest and creosote-bush (larrea) scrub, and on the Valdés Peninsula they prefer sandy, low-shrub terrain. Long legs, reduced collarbones, and sharp senses suit them to running across open plains and steppe — when they move, their gait has been compared to that of a deer or antelope.

Behavior and diet

Maras are largely herbivorous, eating green vegetation and fruit; in the Monte Desert, monocots make up about 70% of the diet and dicots the remaining 30%, with preferred grasses from the genera Chloris, Pappophorum, and Trichloris, and dicots including Atriplex lampa, Lycium species, and Prosopis species. They're primarily diurnal, spending roughly 46% of a typical day feeding. Light, rainfall, and temperature all boost daily activity, while darkness and high humidity suppress it; the preferred temperature is around 20°C (68°F). Activity is unimodal — one active period — in winter, and bimodal the rest of the year. Females spend more time feeding than males do, driven by the demands of pregnancy and nursing, while males spend much of the day sitting watch for predators, which include felids, grisons, foxes, and birds of prey, particularly targeting young maras.

Socially, maras combine two traits rarely seen together: strict monogamy and communal breeding. A pair stays together for life, with a new partner taken only after the other dies; the male maintains the bond largely by following the female everywhere she goes, marking her with urine and scent-marking the surrounding ground so that the area around her functions as a mobile territory. Pairs breed alone or alongside other pairs in warrens that can hold up to 29 pairs at once. In southern Argentina, breeding runs from August to January, with gestation lasting 100 days in the wild; most births in Patagonia fall between September and October. Wild females produce one litter a year, though captive females can produce up to four.

Young are raised in dens dug for the breeding season, sometimes shared by litters from as many as 22 pairs. Communal denning improves survival — pups in larger groups fare better than those in smaller ones. One pair visits the den at a time, for about an hour, while the other parents circle nearby; a female typically nurses one or two pups at a time, occasionally including pups that aren't her own, though she may also try to block outside pups from nursing. For the first three weeks pups stay close to the den, with frequent body contact, huddling, and play; afterward they leave the den to graze alongside their parents, and they're weaned by 13 weeks. Maras communicate with a range of sounds — an inflected "wheet" to seek contact, low repetitive grunts while following another mara, tooth-chattering and low grunts when threatened, and short grunts during grooming — alongside elaborate scent-marking rituals, including a male urinating on a female's rump and the female spraying urine back at him, both used more often during the breeding season.

Range and habitat

Patagonian maras are found only in Argentina, ranging historically from north-central Argentina south nearly to Tierra del Fuego, across roughly 28° to 50° south latitude. They prefer habitat with shrub cover but also live on overgrazed and barren soils within the Monte Desert biome. In northwestern Argentina they inhabit lowland forest and creosote-bush scrub, while on the Valdés Peninsula they favor sandy ground with low shrubs.

Hunting and habitat alteration have pushed maras out of parts of their historical range, including Buenos Aires Province, where the species has been extirpated. Mara skins have been used to make bedspreads and rugs. Separately, a population of up to 200 maras — likely descended from escaped pets — now lives in the Al Marmoom Desert Conservation Reserve in the United Arab Emirates, well outside the species' native range.

Conservation status

The Patagonian mara is listed as Near Threatened on the IUCN Red List, in a 2016 assessment. It historically ranged from north-central Argentina almost to Tierra del Fuego.

Hunting and habitat alteration have cut its numbers and wiped it out in some areas, including Buenos Aires Province. Mara skins have been used for bedspreads and rugs.

Outside its native range, a population of as many as 200 maras lives in the Al Marmoom Desert Conservation Reserve in the United Arab Emirates, possibly descended from escaped pets.