The world's largest rodent can stay underwater for five minutes
Capybaras weigh as much as an adult person, swim superbly and hide beneath the surface for up to five minutes. They are so relaxed that birds ride on their backs hunting insects. Their scientific name even hints at their mood: it blends Greek words for water, pig and feeling happy.
The greater capybara lives in every South American country except Chile, always near fresh water: rivers, swamps, flooded savannas and reservoirs. It thrives on cattle ranches and has been recorded as high as 1,500 m. Adults reach 106 to 134 cm long and typically weigh 35 to 66 kg, females slightly heavier than males. Its closest relatives are the lesser capybara and the rock cavies, with guinea pigs not far off. The common name comes from Tupi, meaning roughly one who eats slender leaves.
Days follow a routine. Mornings are spent resting on land, the hot early afternoon soaking in water, and late afternoon and night grazing. They are picky eaters, often choosing one plant species over its neighbours, and switch from grasses to reeds in the dry season. To squeeze nutrients from tough grass they eat their own droppings for gut bacteria and bring food back up to chew again, a little like cattle. Like guinea pigs, they cannot make vitamin C, and captive animals without it develop scurvy. Unusually for rodents, they have sweat glands in their skin.
Groups usually number 10 to 20, with a few adult males, several females and young, swelling to 50 or 100 around scarce water in the dry season. They talk in barks, chirps, whistles and purrs, and mark territory with a scent gland on the snout called a morrillo. Mating happens only in water, and a female can refuse a male simply by diving or leaving. After 130 to 150 days she bears around four young, which may suckle from any female in the group.
Birds exploit the capybara's calm, catching insects it disturbs or picking parasites from its hide; when a yellow-headed caracara approaches, capybaras may roll over to offer their bellies. They can live 8 to 10 years, but jaguars, caimans and anacondas usually cut that to four in the wild. The species is not threatened, and escapees turn up in Florida, where Pleistocene capybaras once lived.
Source: Capybara
