Overview

The capybara (Hydrochoerus hydrochaeris) is a large, semi‑aquatic mammal native to much of South America. It is the largest living rodent and is closely associated with rivers, marshes, flooded grasslands and other wet habitats. Capybaras are social, typically seen in groups that feed, rest and keep watch near water. Their combination of terrestrial grazing and aquatic behaviour makes them a distinctive component of many wetland ecosystems.

Physical characteristics

Capybaras have a heavy, barrel‑shaped body, short legs, and a blunt, square muzzle. Adult animals commonly reach lengths around one metre and can weigh several dozen kilograms, making them far larger than most other rodents. Their coarse brown to reddish fur becomes sparser with age, and their eyes, ears and nostrils are set high on the head—an adaptation that permits respiration and observation while most of the body remains submerged. The feet are partially webbed, aiding swimming and movement through soft mud.

  • Body form: stocky, adapted for buoyancy and grazing.
  • Fur and skin: coarse guard hairs over a denser underlayer; older individuals may show thinning fur.
  • Locomotion: capable swimmers that dive and use webs between toes; move on land to graze and rest.

Diet and digestion

Capybaras are herbivores that feed mainly on grasses and aquatic plants; they may also consume fruits and bark when available. Like many hystricomorph rodents, they have a digestive system adapted to fermenting fibrous plant material. To extract additional nutrients, capybaras practice coprophagy—reingesting specialized fecal pellets produced by the hindgut fermentation process.

Behaviour and social structure

Capybaras are gregarious, living in groups that range from small family units to larger aggregations, particularly where resources are abundant. Group structure often includes several adult females, subadults and one or more dominant males. Social behaviours include mutual grooming, vocal communication and coordinated vigilance against predators. Activity patterns vary by region and human disturbance; animals may be most active at dawn and dusk in some areas, and more diurnal in undisturbed habitats.

Reproduction and young

Breeding seasons depend on local climate and food availability; in favorable environments reproduction can occur year‑round, while in more seasonal areas births often peak in wetter months. Females give birth to litters of precocial young that are relatively well developed at birth and begin grazing within days. Mothers and other group members may contribute to care and protection of juveniles until they are independent.

Predators and threats

Natural predators include large cats, such as jaguars and pumas, as well as crocodilians and large snakes; wading birds of prey may take young animals. Humans hunt capybaras for meat and hide in some regions, and local populations can be affected by habitat loss, wetland drainage and conflict with agriculture. Despite these pressures, the species remains widespread in many parts of its range.

Relationship to other rodents

Taxonomically, capybaras belong to a group of hystricomorph rodents that also includes animals such as the domestic guinea pig and, more distantly, the chinchilla. They share certain digestive and dental features with these relatives, but their large size and semi‑aquatic habits set them apart within the order Rodentia.

Human interactions and conservation

People have used capybaras as a source of meat and leather, and the species appears in local folklore and cuisine in parts of its range. Capybaras are also kept in captivity in zoos and, in some places, as unconventional pets. Overall the species is generally widespread and often considered of low conservation concern across much of its distribution, but local declines can occur where wetlands are degraded or hunting is intense. Conservation and management measures vary by country and may include habitat protection, regulated hunting and public education about coexistence.

Ecological role and notable facts

As large, communal grazers closely tied to water, capybaras influence vegetation structure and serve as prey for several apex predators, helping to transfer energy through wetland food webs. Their social behaviour, aquatic adaptations and size make them a prominent and recognizable species in many South American landscapes.

Further information about the species and its natural history can be sought via the scientific name Hydrochoerus hydrochaeris or regional conservation resources focused on South America.