Geographic Range
Neotropical: The pampas of central and southern Argentina.

Physical Characteristics
Mass: 8 to 16 kg
Head and body length= 690-750mm with a tail of 40-50mm.
The generalbody form of a Patagonian cavy is that of a long-legged rodent with a body similar to a hoofed animal. Patagonian cavies are grayish-brown above and white below. The hindquarters have a large white patch. The stiff, dense hair is very fine in texture. The front feet have 4 toes, the back 3 all having a sharp claw. The hind legs are slightly larger than the front. The eyes and nose are large, and the ears are slightly pointed.

Food Habits
Patagonian cavies eat almost any vegetation but prefer grasses and herbs.

Reproduction
Patagonian cavies have very unusual reproductive behavior, especially for mammals. Monogomous for life. a cavy pair breeds two or three times a year, usually around mid-winter and spring, when the female enters her very brief estrus. The litters of 1-3 young are born after a 3 month gestation period. The young are well developed at birth and are quickly placed in a communal den, usually made from a hole or tunnel abandoned by another animal. This den is home to the offspring of as many as 15 cavy pairs. The adult pairs intermittently travel to the den to nurse their young. Pairs do not tolerate other pairs when nursing, and the males drive off other parents. The female uses scent to locate her young and drives off offspring other than her own. The young are weaned after 2-3 months and quickly reach sexual maturity (2-3 months for females, 6 months for males).

Behavior
Patagonian cavies travel in mated pairs and are active mostly during the day. The home range is about 40 ha. The male always follows the female, on guard for rival males and predators. Very little territorality is evident, but males appear to have a dominance hierarchy. Patagonian cavies have a variety of locomotions. They may walk normally, hop in a rabbit-like fashion, gallop, or bounce on all fours (for long distance, high speed travel). These cavies have been clocked at speeds of 45 km/hr for more than 1000 meters. Cavies also vocalize with grunts, grumbles, and screams and spend a great deal of the day basking in the sun. Although cavies spend more of their time in pairs seasonally they will travel in very large groups (70+) to freshly evaporate lakes where food is extremely plentiful.