The capybara (Hydrochoerus hydrochaeris) holds the title of the world’s largest rodent, a semi-aquatic mammal native to the diverse landscapes of South America. These highly social herbivores spend their lives near water sources, such as rivers, swamps, and lakes, a habitat that directly influences their specialized diet. Understanding what capybaras eat requires distinguishing between their natural foraging in the wild and the carefully controlled feeding regimens used in managed care settings.
The Wild Herbivore’s Menu
The capybara’s natural diet consists primarily of grasses, reflecting their specialized role as grazers in their riparian and savanna habitats. During the wet season, when fresh vegetation is abundant, they are selective feeders, consuming large quantities of tender, palatable grasses and specific aquatic plants. An adult capybara is capable of consuming between 6 and 8 pounds of fresh grass to meet its energy demands.
Dietary sources change significantly with the seasons, demonstrating a flexible foraging strategy driven by resource availability. As the dry season arrives and grasses become scarce, tougher vegetation, such as reeds, hard woody plants, and tree bark, becomes a greater part of their intake. Capybaras may also forage for fruits and squashes when they are available, but their reliance on high-fiber, low-nutrient grasses remains constant throughout the year. They also consume submerged or floating flora like water hyacinths and water lettuce, which provides both nourishment and hydration.
Unique Feeding Habits
To maximize the nutritional yield from their high-fiber diet, capybaras employ coprophagy, the re-ingestion of their own feces. They consume nutrient-rich cecotropes, soft pellets produced during the initial digestive process. This behavior allows food to pass through the digestive tract a second time, enabling the absorption of nutrients, proteins, and B vitamins locked within the tough cellulose of plant matter.
The demanding nature of their diet is reflected in their dental structure, as capybaras possess continuously growing teeth (hypsodonty). Constant grazing on abrasive grasses is necessary to naturally wear down their incisors and cheek teeth, preventing overgrowth. Their jaw structure is adapted for this process, featuring a hinge that allows for a side-to-side grinding motion. This continuous grinding action efficiently breaks down the coarse plant fibers, a mechanical process that complements their complex digestive biology.
Managed Diets in Human Care
In zoos, sanctuaries, and as pets, the capybara diet is carefully constructed to mimic the high-fiber, low-protein nutrition they receive in the wild. The foundation of a managed diet is high-quality grass hay, such as Timothy or Bermuda hay, which substitutes for native grasses and satisfies their need for continuous grazing. Constant access to hay is provided to ensure proper gut motility and facilitate the necessary wear on their continuously growing teeth.
To supplement the hay, capybaras are often given commercially prepared pellets designed for rodents or guinea pigs, which provide a complete and balanced nutritional profile. These specialized pellets deliver concentrated vitamins and minerals that can sometimes be lacking in hay alone. Fresh vegetables and small amounts of fruit may be offered as treats, but fruits must be moderated due to their high sugar content, which can cause digestive upset. While capybaras produce some of their own Vitamin C, supplementation is often recommended, as they are related to guinea pigs, which do not produce the vitamin, ensuring they receive all necessary dietary requirements.