The Capybara is a large, semi-aquatic rodent that is found inhabiting the water-logged regions of Central and South America. Closely related to other South American rodents such as Chinchillas and Guinea Pigs, the Capybara is the largest rodent in the world weighing up to 75kg and measuring nearly 1.4 meters long. Despite their enormous size though, thesemammals have adapted well to life in the water and have a number of distinctive characteristics that aid their amphibious lifestyle, including the webbed skin between their toes which is particularly helpful when swimming. Interestingly enough, the common name of the Capybara is thought to mean “Master of the Grasses”, whilst it’s scientific name comes from the Greek word for water hog.
The Capybara is a heavy, stocky-looking animal with a short head and muzzle in comparison to it’s body and hardly any tail at all. They have short but sturdy limbs and hoof-like claws on their toes which along with the webbing, helps the Capybara both when negotiating the slippery banks and with swimming and also prevents the Capybara from sinking too deeply into the surrounding mud. Their coarse, short fur is pale to dark brown in colour with varying tinges of yellow, red and grey and is perfectly designed to dry out quickly once the Capybara is back on land. One of the Capybara’s most distinctive features is the fact that their eyes, ears and nostrils are all positioned on top of it’s head meaning that they still have excellent sight, sound and smell whilst in the water. The placement of these features also means that when threatened, the Capybara can retreat into the water only leaving these parts of it’s body exposed to hide from potential predators.
The Capybara is found throughout a variety of habitats in Central and South America providing that there is a constant source of standing freshwater. They are found in Panama, Colombia, Venezuela and Peru, down through Brazil and Paraguay and into northern Argentina and Uruguay where they are most commonly found in swamps, marshes, rivers and lakes. The Capybara can be found inhabiting grassy plains and even in rainforests where they occupy territories in herds, with these areas reported to be adequate territories year round even with the differing seasons. During the dry season the Capybara must have water and areas where they are able to feed (often small sandbars in the water), but in the wet season when the area floods they must still be able to graze which they often do on the grassy banks.
Very social animals, capybaras live in small family groups of about 10-20. A typical group includes one dominant male, several females, their offspring, and a few subordinate males. The dominant male, usually the heaviest, stares down the other males in the group, driving them to the outer edges of the group. Here, the subordinate males act as sentinels (or lookouts), performing warning barks when a predator is near.
In some cases, a subordinate male will challenge the leader. The two capybaras will charge each other, rear up onto their hind legs, and engage in a scuffle until one flees the scene.
Capybaras are herbivores, grazing mainly on grasses and aquatic plants, as well as fruit and tree bark. They are very selective feeders and will 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. Plants that capybaras eat during the summer lose their nutritional value in the winter and therefore are not consumed at that time. The capybara’s jaw hinge is not perpendicular and they thus chew food by grinding back-and-forth rather than side-to-side. Capybaras are autocoprophagous, 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 may also regurgitate food to masticate again, similar to cud-chewing by a cow. As is the case with other rodents, the front teeth of capybaras grow continually to compensate for the constant wear from eating grasses; their cheek teeth also grow continuously.
Despite the large size and secretive aquatic nature of this large rodent, their slow and gentle disposition makes them a rewarding meal for numerous hungry predatorsthroughout their natural range. Wildcats including Jaguars, Pumas and Ocelots are the primary predators of the Capybara along with Caimans and Eagles that can hunt the younger ones from the sky above. The Capybara is also one of the best sources of food for the world’s heaviest snake, the Anaconda, along with other species of large snake. The Capybara is also hunted by Humans in parts of it’s natural range for both it’s meat and the hide which is prized amongst some. Although the global Capybara population is not considered to be under threat, numbers in these areas have declined. Habitat loss also affects Capybara populations through Central and South America as they are specifically adapted to life in their unique watery wilderness.
Due to their slow and generally gentle nature, Humans have lived alongside Capybara for hundreds of years peacefully. However, they may not be aggressive animals but are often killed in certain areas for their meat and skin which has led to population declines in these regions. The Capybara has also been affected by Human activity in their native regions in general including both growing Human settlements and land clearance for agriculture.