What Do Capybaras Eat? Grasses, Water Plants and More

The main foods: grasses and water plants

The capybara is a true grazer. Most of what it eats is grass, cropped short with its chisel-like front teeth, together with sedges and soft aquatic plants growing in and around shallow water. Its name reflects this: “capybara” comes from the Tupi language of Brazil and is usually translated as “grass eater”.

Capybaras are surprisingly choosy. Studies of wild herds have found that they focus on a small number of favorite plants and often pass over other species growing right next to them. Much of the diet can come from just a handful of grass and sedge species, and they prefer young, green, protein-rich growth to old, dry stems.

Because they feed along the water’s edge and in floating meadows, capybaras are one of the few large grazing mammals in many South American wetlands. In places such as the Llanos and the Pantanal they share grazing land with cattle, which is one reason some ranchers see them as competitors.

How diet changes with the seasons

Much of the capybara’s range has a wet season and a dry season, and its diet shifts between them.

In the dry season, green grass becomes scarce and capybaras gather around the last pools of water, sometimes in herds of 50–100 animals. They then eat a wider variety of plants and switch to more abundant reeds. Near farms they may also feed on crops such as grains, melons and squashes, which can bring them into conflict with farmers.

Why capybaras eat their own droppings

Grass is cheap and plentiful, but it is full of cellulose, a tough plant fiber that no mammal can digest on its own. Capybaras rely on bacteria living in a large pouch of the gut called the cecum to break it down. The trouble is that the cecum sits near the end of the digestive tract, so many of the nutrients released there would otherwise pass straight out.

The solution is coprophagy, the eating of feces. Part of each morning is spent re-eating soft droppings from the previous day. This gives the food a second trip through the gut, recovers protein and vitamins made by the bacteria, and helps keep a healthy population of gut bacteria. Rabbits, hares and the capybara’s relative the guinea pig use the same trick.

Capybaras have also been reported to bring up food and chew it again, a little like cattle chewing the cud, although they are rodents and do not have the multi-chambered stomach of a cow.

Teeth that never stop growing

Like all rodents, capybaras have two pairs of large, ever-growing front teeth (incisors), one pair in each jaw, used to nip off grass. Grass contains tiny particles of silica that wear teeth down quickly, so a grazer needs teeth that keep pace with the wear.

In the capybara, not only the incisors but also the cheek teeth used for grinding keep growing throughout life. Each cheek tooth is made of many thin plates that form a broad grinding surface for shredding grass. An adult capybara has 20 teeth in all.

When and how capybaras feed

Capybaras usually graze from late afternoon through the evening and night, and again around dawn. They avoid feeding in the midday heat, when they rest in water or mud to stay cool. Where they are hunted by people, they become more nocturnal and feed mostly in darkness.

A grazing herd moves slowly across the grass, heads down, but some animals keep looking up to watch for predators such as the jaguar, which is also covered in what do jaguars eat?. If one capybara barks an alarm, the whole group runs back to the water. Grazing capybaras also stir up insects, which attract birds such as cattle tyrants that follow the herd or ride on the capybaras’ backs.

What baby capybaras eat

Capybara pups are born well developed, with fur and open eyes, and they begin nibbling grass within about a week. They continue to drink milk until about three to four months old and can suckle from any nursing female in the group, not just their own mother. Young capybaras grow quickly on this mix of milk and grass, and they stay with the herd’s other pups in a nursery group while the adults watch for danger.

Capybara diet facts at a glance

• Diet type: herbivore (grazer)
• Main foods: grasses, sedges and water plants
• Dry-season foods: reeds, bark, fruit, grains and other available plants
• Daily intake: about 2.7–3.6 kg (6–8 lb) of fresh plants for an adult
• Feeding time: late afternoon, night and dawn
• Special habits: re-eating droppings, ever-growing incisors and cheek teeth