Capybara (Hydrochoerus hydrochaeris) is an unusually large rodent species. In fact, it is the largest living rodent in the world – although it resembles a rat, it is the size of a Labrador Retriever.
Capybaras are found throughout most of South America, living in forests near water bodies. They enjoy being submerged and spend most of their time swimming, evading jaguars, and consuming vast amounts of grass.
Capybaras can weigh between 35 to 66 kg and can reach lengths of up to 1.3 meters. Females are typically larger and heavier than males. They stand about 60 cm tall. Their size is comparable to that of Labrador Retrievers, although these rodents are stockier and heavier.
This species is closely related to guinea pigs and rock cavies. However, they are not the largest rodents to have ever existed – Josephoartigasia monesi, which lived 2 to 4 million years ago, resembled capybaras but weighed a ton and could grow up to 3 meters long!
Ancient Josephoartigasia monesi had a short neck and stocky body, which contained a lot of fat tissue. They typically walked and ran on four legs like modern wild cattle. Similar to capybaras, they had four toes on their front feet and three toes on their back feet, with webbing between their toes allowing them to swim. Unlike most modern rodents that have long tails, they either lacked tails or had much shorter tails in proportion to their bodies.
The scientific name of the capybara comes from Greek and translates to “water pig” (both the genus and species names). Although they are not pigs, these rodents have a fondness for water.
They are semi-aquatic mammals and spend significant time in the water. Most of their lives are spent in dense forests alongside lakes, rivers, or swamps.
Capybaras have special adaptations for living in wetland areas. They possess slightly webbed feet that aid in swimming. They can also press their ears against their heads to prevent water from entering and can remain submerged for up to 5 minutes. This behavior may help them evade predators.
Their eyes, ears, and nostrils are located on the top of their heads, allowing them to submerge most of their heads in the water. This positioning also helps minimize their exposure to predators while still enabling them to observe their surroundings.
This giant rodent even mates in the water.
Today, the largest rodent in the world is the capybara, which resides in Paraguay, Argentina, Brazil, Bolivia, Colombia, Venezuela, and most of Northern South America. Compared to other rodents, they are still quite large with a body length of 1.3 meters, a shoulder height of 0.5 meters, and a weight ranging from 35 to 66 kg.
Capybaras are picky eaters, consuming specific types of vegetation. However, they will eat a wider variety of plants during the dry season when their preferred food is scarce.
This giant rodent primarily feeds on grass and aquatic plants. They also consume their own feces to maximize nutrient intake and aid digestion by accumulating beneficial bacteria.
Elizabeth Congdon, a professor and capybara researcher at Bethune-Cookman University in Florida, told The Verge: “It is called coprophagy – a mechanism to extract all the nutrients.”
Like other rodents, their teeth continuously grow due to constant wear from chewing.
They eat 3-4 kg (the equivalent weight of an average cat) of grass daily. Capybaras chew side to side (like camels), while humans chew up and down.
True to its name, the capybara particularly loves water. They even mate while submerged. Capybaras can dive and stay underwater for up to 5 minutes. According to National Geographic, they are “excellent swimmers.” Their webbed feet make it easy for capybaras to move through the water. Their semi-aquatic lifestyle also helps them evade predators like wild cats, eagles, or anacondas.
Under ideal conditions, capybaras can live up to 10 years, but they typically do not live longer than 4 years in the wild due to being preyed upon by jaguars, puma, eagles, caimans, and anacondas.
This species is social and often lives in groups of 10-20, although during the dry season, they may form groups of 40 or more.
On land, this species also possesses impressive speed. It can accelerate up to 35 km/h – comparable to that of a horse.
The behavior of this animal is often compared to that of cattle — they just need to be left in peace with grass to eat.
However, capybaras seem to be quite trainable: they are sometimes kept as pets, and a blind person in Suriname has used them as guide animals. People who raise these giant rodents also say they learn faster than dogs when performing simple tasks.
Capybaras are also kept as pets. In Japan, a zoo named Izu Shaboten even gives them hot baths to attract visitors.
