Capybaras are semiaquatic mammals[15] found throughout all countries of South America except Chile.[19] They live in densely forested areas near bodies of water, such as lakes, rivers, swamps, ponds, and marshes,[14] as well as flooded savannah and along rivers in the tropical rainforest. They are superb swimmers and can hold their breath underwater for up to five minutes at a time. Capybara have flourished in cattle ranches.[7] They roam in home ranges averaging 10 hectares (25 acres) in high-density populations.[7] Many escapees from captivity can also be found in similar watery habitats around the world. Sightings are fairly common in Florida, although a breeding population has not yet been confirmed.[20] In 2011, one specimen was spotted on the Central Coast of California.[21] These escaped populations occur in areas where prehistoric capybaras inhabited; late Pleistocene capybaras inhabited Florida[22] and Hydrochoerus hesperotiganites in California and Hydrochoerus gaylordi in Grenada, and feral capybaras in North America may actually fill the ecological niche of the Pleistocene species.[23]
Capybaras are herbivores, grazing mainly on grasses and aquatic plants,[14][24] as well as fruit and tree bark.[15] They are very selective feeders[25] and feed on the leaves of one species and disregard other species surrounding it. They eat a greater variety of plants during the dry season, as fewer plants are available. While they eat grass during the wet season, they have to switch to more abundant reeds during the dry season.[26] Plants that capybaras eat during the summer lose their nutritional value in the winter, so they are not consumed at that time.[25] The capybara's jaw hinge is not perpendicular, so they chew food by grinding back-and-forth rather than side-to-side.[27] Capybaras are autocoprophagous,[28] meaning they eat their own feces as a source of bacterial gut flora, to help digest the cellulose in the grass that forms their normal diet, and to extract the maximum protein and vitamins from their food. They also regurgitate food to masticate again, similar to cud-chewing by cattle.[28][29] As is the case with other rodents, the front teeth of capybaras grow continually to compensate for the constant wear from eating grasses;[19] their cheek teeth also grow continuously.[27] Like its relative the guinea pig, the capybara does not have the capacity to synthesize vitamin C, and capybaras not supplemented with vitamin C in captivity have been reported to develop gum disease as a sign of scurvy.[30]They can have a lifespan of 8–10 years,[31] but tend to live less than four years in the wild due to predation from big cats like the jaguars and pumas and non-mammalian predators like eagles and the caimans.[19] The capybara is also the preferred prey of the green anaconda.[32]
Fun Fact: While Capybaras feel at home by the water’s edge, they certainly know their way around the land, and are capable of reaching speeds of up to 35 kilometers an hour—that’s as fast as a horse!