Capybaras, also known as carpinchos or water hogs, are large South American rodents in the family Hydrochaeridae. Hydrochaeris hydrochaeris is the larger of the two species of capybaras, and is the world's largest rodent. It can reach a body weight of 110 lb (50 kg), a body length of 4.5 ft (1.3 m), and a height of 1.5 ft (50 cm). Hydrochaeris isthmius is about half this size. H. hydrochaeris has a wide distribution in South America, while H. isthmius has a relatively restricted distribution in Panama, western Colombia, and northwestern Venezuela. Some scientists, however, regard H. hydrochaeris and H. isthmius as a single species.
Capybaras have a large head with a blunt snout and small ears. The body is stout, robust, and almost tailless. The feet of capybaras are partially webbed and have four digits on the forefeet and three on the hind, and all have strong claws. The fur of capybaras is long, coarse, and rather sparse, so that naked skin can be seen. The body color is generally brownish or grayish. Capybaras have a strong physical resemblance to another group of much smaller South American rodents, the closely related guinea pigs (family Caviidae).
Capybaras are semi-aquatic animals, occurring in a wide range of terrestrial habitats in the vicinity of freshwater, including the forested edges of streams, rivers, ponds, lakes, swamps, and marshes. Capybaras can run easily on land, and when disturbed near water they generally swim and dive to escape. These animals can swim with only their eyes and nostrils exposed to the atmosphere, or they can swim completely submerged.
Capybaras are herbivores, eating a wide range of aquatic, near-shore, and riparian plants. Capybaras sometimes feed with cattle and other domestic herbivores, and they are known to raid gardens for vegetables, fruits, and grains. Capybaras feed most actively during the moderate temperatures of dawn and dusk, spending the heat of the day in a cool, underground excavation. However, in places where they are frequently disturbed or hunted by people, capybaras generally develop a nocturnal habit.
Capybaras are peaceful, social animals, living in extended family groups containing as many as several tens of animals. They give birth once a year to two to eight offspring. Capybaras are known to live as long as 10 years in the wild.
Capybaras are hunted by various species of natural predators, including jaguar and large caimans. They are also hunted by humans, because they are often regarded as agricultural pests. The meat of capybaras is sometimes consumed, although it is not regarded as one of the higher-quality game species. The capybara is still widespread and abundant over much of its natural range.