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Hydrochoerus hydrochaeris


The world's largest rodent stands 20-25 inches at shoulder, is 3.5-4.5 feet long, and weighs 77-150 pounds; females are slightly larger than males.

Built for an aquatic lifestyle, the capybara's body is barrel-shaped, sturdy, and tailless. The front legs are slightly shorter than the hind legs, and the feet are partially webbed, allowing the animal to walk on wet, spongy ground as easily as it moves through water. With eyes, ears, and nostrils positioned on top of the head, the capybara can stay submerged just under the surface of the water without losing the ability to keep track of its environment.

The coarse, thin fur is reddish brown over most of the body, turning yellowish brown on the belly and sometimes black on the face.


Distribution and Habitat

The capybara's range extends through most of South America east of the Andes, from Panama into the Argentinian pampas. Flooded grasslands are a favored habitat, as are marsh edges and lowland forests where grazing is good and there is water year-round. However, they occupy a range of habitats, including dry forest, scrub, and grasslands throughout South America, with a proximity to a permanent water source being the only requirement.

Habits and Behaviors

Capybaras live in groups of around 10 adults of both sexes, although groups can range in size from 3 to 30 and larger aggregations often form around water resources during the dry season. Each group maintains and defends a territory that encompasses feeding and wallowing sites. Group living appears to be extremely important to capybara survival, as "loner capybaras" are excluded from most grazing habitat and have no chance of finding a mate. Group membership changes rarely, and a territory can be maintained by one group for 3 years or more.

Among males, there is a strict dominance hierarchy enforced by chasing and, rarely, fights.

Because of their large body size, capybaras are susceptible to heat stress, and the hottest part of the day is spent in the water.

Vocalization appears to be very important in capybara groups, but the purpose of many of the sounds made is unknown. However, young vocalize almost constantly and vocal communication among adults is also common. Individuals bark to warn the group of danger, this often results in the whole group rushing into the relative safety of the water. Scent is also important, especially in mating and establishing dominance.


Dominant males in social groups try to monopolize mating activity, but this can be nearly impossible, especially in larger groups. Little research has been done on female mate choice in capybaras, but females have been observed mating with both dominant and subordinate males.

Capybaras breed throughout the year, with a peak in breeding activity at the beginning of the rainy season. The mating takes place in the water.

The mother gives birth to 2-8 young after a gestation of about 150 days. Precocial from birth, the young are able to walk and swim within hours. They begin eating grass at about a week, but will not br weaned until about their third month. Young capybaras stay with their parents' group until they are about a year old. Both before and after weaning, the young move around together in a creche, and some of the work of parenting (such as suckling and watching for danger) is shared among all adults in the group. Little is known about individual parental care in capybaras, but because of the precocial state of the young and the system of cooperative parenting the time and resources spent by each parent after birth are minimal.

Capybaras have a lifespan of about 6 years in the wild, and up to 12 years in captivity.


Capybaras feed on grasses and aquatic plants, as well as bark and fruit. They are also known to both regurgitate their food in order to chew it again and also to eat their own droppings.

Scientific Classification

phylum Chordata
subphylum Vertebrata
class Mammalia
order Rodentia
family Caviidae
genus & species Hydrochoerus hydrochaeris

Animal Diversity Web

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The Robinson Library >> Science >> Zoology >> Mammals >> Order Rodentia

This page was last updated on March 15, 2018.