Patagonian Mara - Social Behavior and Reproduction

Social Behavior and Reproduction

The social organizations have a unique combination of monogamy and communal breeding. Being monogamous, pairs of maras stay together for life with replacement of partners only occurring after its death. The male has almost the sole responsibility in maintaining the pair by following the female wherever she goes. A male will mark his female with urine and mark the ground around her with secretions from his glands and with faeces, making the grounds around the female a mobile territory. Pairs will breed together alone or with other pairs in warrens shared by up to 29 pairs. Maras breed, at least in southern Argentina, from August to January. Gestation lasts 100 days in wild. Most births, at least in Patagonia, occur between September and October which is before the summer dry season and after the winter rains. Female produce one litter each year in the wild, but can produce as many as four litters a year in captivity. Young can walk almost immediately postpartum.

Dens are dug during the breeding season for the young to be raised. Litters from 1-22 pairs are grouped together in these dens. Communal living provides protection from predators with the survival rate for young being higher in larger groups than in smaller groups. One pair visits the den at a time for around one hour and the other parents will circle around the den. 1-2 pups are nursed at a time by a female. A female may sometimes nurse a young from another pair. While a female may prevent young other than her own from nursing her, some young are able to steal milk. There is no active cooperation raising of the young by mothers. For the first three weeks, young remain near the den. At this time there is low inter-individual distance, frequent body contact, huddling, allogrooming and extended play among the pup. After this, the young are able to leave the den and graze with their parents. Young are weaned after 13 weeks.

Maras will make a number of vocalizations during grazing or slow locomotion. When seeking contact, a mara will emit an inflected wheet while a low repetitive grunt is made when following a conspecific. Mara tooth chatter and emit low grunts when threatened. They also produce a series of short grunts when grooming. Scent marking is used by maras for complex and intense social interactions. Maras will stretch and sniff the soil and then sit upright with an arched back and the anogenital area flattened to the ground, a process known as anal digging. In addition a male will stand on his hind legs and urinate on a female’s rump to which the female will respond by spraying a jet of urine backwards into the face of the male. The male’s urination is meant to repel other males from his partner while the female’s urination is a rejection of any approaching male when she is not receptive. Both anal digging and urination are more frequent during the breeding season and are more commonly done by males.