Capybara

Name and taxonomy

The name capybara comes from the Tupi word ka'apiuara, which joins the words for leaf, slender, eat and doer. It means grass eater. The genus name Hydrochoerus comes from the Greek for water and pig, and the species name hydrochaeris means one who enjoys water. In Spanish the animal is called carpincho in the south and chiguire in Venezuela and Colombia, and in Portuguese it is capivara. German speakers call it Wasserschwein, the water pig.

The capybara belongs to the family Caviidae, which also holds the guinea pigs and the rock cavies. Within that family it sits in the subfamily Hydrochoerinae with the rock cavies of the genus Kerodon. Older classifications gave the capybaras a family of their own, Hydrochoeridae, but molecular studies since 2002 placed them inside Caviidae. Its only living relative in the genus is the lesser capybara, Hydrochoerus isthmius, of Panama and northern South America. No subspecies are recognised.

Evolution and relatives

The capybara is a caviomorph rodent, part of the South American group that also includes the agouti, the chinchilla and the coypu. Fossil capybaras include the genera Cardiatherium, Phugatherium, Hydrochoeropsis and Neochoerus. The fossil record once looked far richer than it is, because capybara molars change shape as an animal ages. In one case, bones assigned to four genera and seven species turned out to be one species, Cardiatherium paranense, at different ages.

Capybaras once lived far outside South America. In the late Pleistocene one species lived in Florida, Hydrochoerus hesperotiganites lived in California and Hydrochoerus gaylordi lived in Grenada. Escaped capybaras now turn up in Florida, and one was seen on the Central Coast of California in 2011. Those escapes may be filling the niche the Pleistocene species left empty.

Appearance

The capybara is heavy and barrel-shaped, with a broad blunt head and almost no tail. Adults measure 106 to 134 centimetres from nose to rump and stand 50 to 62 cm at the withers. Most weigh 35 to 66 kilograms, and the average in the Venezuelan Llanos is 48.9 kg. The record is a wild female from Brazil at 91 kg. Females are slightly heavier than males, which is unusual among mammals. A wild male from Uruguay reached 73.5 kg, and an 81 kg animal was reported in Sao Paulo.

The coat is coarse and thin, red-brown on the back and yellow-brown on the belly, sometimes black on the face. Hairs run from 30 to 120 millimetres long, and there is no soft underfur. Sweat glands open on the hairy skin, a rare feature among rodents. The feet are partly webbed, with four toes in front and three behind, and the hind legs are a little longer than the front legs. An adult male carries a bare oval gland on top of the snout, called the morrillo. The front teeth grow throughout life to keep pace with the wear of grazing, and so do the cheek teeth.

Habitat and range

The capybara lives east of the Andes across Colombia, Venezuela, the Guianas, Brazil, Ecuador, Peru, Bolivia, Paraguay, Uruguay and northern Argentina. It is absent only from Chile among the countries of South America. GBIF holds records from 26 countries, but that figure includes zoos and escapes, not the native range. iNaturalist lists 18,158 observations of the species.

It needs fresh water close at hand, and it lives beside rivers, lakes, ponds, streams, swamps and reservoirs. Flooded savanna, marsh edges and gallery forest along rivers are its favourite habitats, and it also uses dry forest and scrub. The Llanos of Venezuela and the Pantanal of Brazil hold some of the densest populations. Most animals live in the lowlands, and the highest record is 1,500 metres in the Chapada dos Veadeiros National Park. Cattle ranches suit it well, because they combine open grazing with permanent water. A group's home range covers about 5 to 16 hectares in rich habitat and can exceed 200 ha where food is poor.

Diet and feeding

The capybara is a grazer. Grasses and water plants make up most of its diet, with sedges, reeds, fruit and bark added at times. It is a picky feeder and will strip the leaves of one plant species while it ignores the plants around it. In the dry season it eats a wider range of plants, and it switches from grass to reeds when the grass fails. It sometimes raids gardens and fields for melons, squashes and grain.

Grass is hard to digest, so the capybara passes it through twice. Each morning it eats its own soft droppings, which carry the gut bacteria that break down cellulose. It also brings food back up to chew again, much as a cow chews the cud. The jaw hinge is set so that the animal grinds its food with a front-to-back motion, not a sideways one. Like the guinea pig, it cannot make vitamin C, and captive animals without a supplement develop gum disease.

Behaviour and social life

Capybaras are most active around dawn and in the early evening. They rest on land in the morning, spend the hot afternoon in the water, then graze through the late afternoon and night. A large body loses heat slowly, so they wallow to keep cool. Where hunting is heavy they become nocturnal. They swim strongly, because the body is only slightly denser than water, and they can stay under for up to five minutes.

A typical group holds 10 to 20 animals: a few adult males, more adult females and their young. In the dry season groups of 50 or even 100 gather around the last water. A single dominant male leads each group and holds a territory that includes water, grazing and a resting place. Males keep a strict rank order by chasing, and they rarely fight. Groups are stable, and one group can hold the same territory for more than three years.

A lone capybara is rare, because an animal without a group is shut out of the best grazing and cannot find a mate. Some group members watch while others feed, and a bark sends everyone into the water. Capybaras do not travel far: in one study 40% of marked animals were recaptured within 100 metres two years later. They tolerate other animals well, and birds ride on their backs to pick off insects.

Communication and senses

Capybaras bark, chirp, whistle, huff and purr, and the young call almost constantly. A dog-like bark warns the group of danger. A female in heat whistles through her nose to tell males she is ready. The purpose of many sounds is still unknown.

Scent matters as much as sound. The male's morrillo gland gives off a white liquid that acts as a chemical fingerprint of his rank. He rubs it on plants to mark territory and smears it on his own body to advertise for a mate. Both sexes have anal glands, and the male's are lined with hairs that carry a long-lasting crystalline scent. Other capybaras taste these marks to learn who left them. Like other rodents, the capybara probably relies more on smell and hearing than on sharp eyesight.

Reproduction and life cycle

Capybaras breed all year, with a peak at the start of the rains. In Venezuela births peak in April and May, and in Mato Grosso in October and November. When a female comes into heat her scent changes, and a male follows her closely, sometimes for a long time. A higher-ranking male often drives him off and takes his place. Mating happens only in the water, and a female who does not want a male simply dives or walks out.

The dominant male gets more matings than any single rival, but the subordinate males together father more young than he does. Gestation lasts about 150 days. A litter holds one to eight pups, usually about four, born on land. The mother rejoins the group within hours, and the pups follow as soon as they can walk. They graze within a week, and any female in the group will nurse them until weaning at about 16 weeks.

The young of a group form a creche, and every adult shares the watch for predators. Pups are small, slow and easily tired in their first year, so the group's protection keeps them alive. They stay with the group until about a year old. In the wild a capybara lives up to 10 years, though most die before four, and the captive record is 15.1 years.

Predators and threats

The capybara feeds many predators. Jaguars, ocelots and cougars take adults, and caimans, green anacondas and eagles take the young. A grazing capybara looks up constantly, and one bark sends the group into the water. There it floats with only the eyes and nostrils above the surface, or dives and swims away below. Because so many die young, few wild capybaras pass four years of age.

People are the other main predator, and hunting for meat and hide has cut some local populations. Ranchers sometimes kill capybaras as competitors for cattle pasture. Ticks on capybaras can carry Rocky Mountain spotted fever, and the animals are suspected reservoirs of a Lyme-like disease in Brazil.

Population and conservation

The IUCN Red List rates the capybara as Least Concern. It has a very wide range, lives in many protected areas and reaches high densities, up to nearly 15 animals per hectare in the Pantanal. The population is stable across most of South America. Fast breeding helps it recover from hunting. A female can raise one or two litters a year, and the young breed within a few years.

Over-hunting has reduced numbers in some places, and Colombia's Valle del Cauca lists it as regionally threatened. Farming the animal for meat has eased pressure on wild herds and given landowners a reason to keep wetlands intact. Capybaras have adapted well to towns and parks, and they are now a familiar sight in South American cities. In Europe, Drusillas Park in Sussex keeps the studbook that tracks every captive capybara birth, death and move.

Relationship with humans

South Americans have eaten capybara for centuries, and the meat and leather are both prized. In Venezuela capybara is a Lent and Holy Week dish, because the Catholic Church is said to have classed the animal as fish. The story is that its watery habits convinced early priests, and the dispensation is often dated to the 1700s. Ranching capybaras has been proposed to curb illegal hunting, and they graze more efficiently than cattle. Capybara grease from the thick fatty skin is also collected.

The animals are docile and let visitors pet and hand-feed them in zoos and parks. Keepers discourage contact, because their ticks can carry disease. A capybara cafe in St Augustine, Florida, lets visitors scratch their heads. Hot spring baths for capybaras at Izu Shaboten Zoo in Japan have drawn millions of video views. The bathing capybaras inspired plush toys and the anime character Kapibara-san.

In culture and myth

In South American folklore the capybara is thought to stand for fertility, abundance and the water spirits. In some stories it is thought to bring rain in a drought. In Paraguayan tales it may appear as a prankster. The Lent legend, in which the Church declared the capybara a fish, is the best-known story about the animal.

In the 2020s the capybara became a meme, and one common format sets it to Don Toliver's song After Party. A capybara song went viral on TikTok in 2022. Fans in Japan and China treat it as a model of calm, and writers have called its manner buddha-like. In August 2021 capybaras overran Nordelta, a gated estate north of Buenos Aires built on their wetland. Social media users joked that the rodents had become a symbol of class struggle.