8 Surprising Facts About Capybaras

An adult and baby capybara standing side by side at the water's edge

Kevin Schafer / Getty Images

The capybara is a semiaquatic mammal and the world’s largest rodent. These social creatures have partially webbed feet and eyes, ears, and nostrils on the top of their heads, making them well-suited to their wetland habitat. Found along the water’s edge throughout South America and portions of Central America, capybaras are not endangered. However, their populations have declined in some areas due to hunting.

From their plant and poop-based diet to their reputation as nature’s ottoman, learn more fascinating facts about the capybara.

1. Capybaras Are the World’s Largest Rodents

Standing close to 2 feet tall at the shoulder and weighing up to 150 pounds, capybaras (Hydrochoerus hydrochaeris) are the largest rodents in the world. They have a barrel-shaped body and no tail, and are significantly larger than their closest relatives, guinea pigs and cavies. These semiaquatic mammals are found throughout South America and portions of Central America near marshes, grasslands, and forests where water is readily available.

The genus Hydrochoerus includes one additional species, the lesser capybara, or Hydrochoerus isthmius. The lesser capybara is similar in appearance but smaller than the capybara.

2. They Are Semiaquatic

family of five capybara babies and one adult swimming in water near green plants on shore
Alexander Yates / Getty Images

Capybaras have partially webbed feet, making them great swimmers. Their eyes, ears, and nostrils are located at the top of their heads, like hippos, enabling them to keep most of their bodies below water while they watch out for predators. Capybaras are able to completely submerge themselves for up to five minutes, allowing them to hide from predators like jaguars, caimans, and anacondas.

During the breeding season, the male capybara will follow the female around until they mate in the water. On hot days, capybaras soak in shallow water to keep themselves cool.

3. Their Teeth Never Stop Growing

Tambako The Jaguar / Flickr / CC BY-ND 2.0

Capybaras have two long, front teeth, and like other rodents, these teeth never stop growing.Their incisors are strong and chisel-like, making them highly effective at cutting through grass. In order to keep their teeth to a reasonable length, capybaras must wear them down by grinding and chewing on food or bark. Their molars keep growing throughout their life as well, but they wear down from the constant grinding capybaras do to masticate their greens.

4. They Live in Groups

A group of capybaras with two adults, two babies, and one young capybara
Kevin Schafer / Getty Images 

Capybaras are highly social animals that live in groups of around 10 to as many as 30 individuals. The groups are stable and work together to defend their habitat. The females raise their babies together, and young capybaras will nurse from several different moms. The herd also keeps a watchful eye on young capybaras who are more susceptible to predators.

5. They Have Unique Vocalizations

Capybaras are highly communicative with members of their groups. They make unique sounds to share important information—warning of danger, signaling a move, and keeping track of their young. The sounds include teeth-chattering, squealing, whining, whistling, crying, barking, and clicking; each sound has a different meaning and is specific to their individual social group. Capybara young are particularly vocal, emitting sounds almost constantly.

6. They Eat Plants

Capybaras are a vegetarian mammal species. These herbivores feed primarily on aquatic plants, grasses, fruits, and bark. Their diet varies with the seasons—but they eat a lot—with adults consuming the equivalent of 6 to 8 pounds per day. During the dry season, they add reeds, grains, melon, and squash to their diet. In order to avoid predators, capybaras prefer to eat at dawn or dusk.

7. They Also Eat Poop

In order to get the most nutrition out of every meal, capybaras are autocoprophagous, meaning they eat their own feces. This practice, which they participate in each morning, provides them with bacterial flora essential to proper digestion. Because the grasses they consume are hard to digest, this process allows their bodies another chance to absorb the previous days’ fibrous meal.

8. They're a Great Place to Sit

yellow cattle tyrant on the back of a capybara in the bushes
Richard McManus / Getty Images

Sometimes referred to as "nature's ottoman," capybaras have developed a reputation as being a nice place to take a load off. They have a mutualistic relationship with birds like the yellow-headed caracara who feed on insects from the rodents’ back while the animal benefits from getting rid of the pesky bugs. Capybaras have a commensalistic relationship with birds like cattle tyrants, which travel with the large rodents to snag whatever insects they pick up.

Why This Matter to Treehugger

Understanding the needs and behaviors of our fellow creatures is key to protecting biodiversity and habitat conservation. We hope that the more we learn about amazing species like the capybara, the more motivated we’ll all be to help protect the grasslands, forests, and bodies of water they call home.

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