The capybara, the world’s largest rodent, is a unique herbivore native to the tropical and subtropical regions of South America. They are semi-aquatic mammals, found throughout the continent’s dense forests, savannas, and wetlands near bodies of water. Their remarkable size and specialized lifestyle are supported by a highly fibrous, plant-based diet and a digestive system adapted to extract nutrition from tough vegetation. This information explores the specific dietary requirements and consumption habits that support this giant grazing rodent in both its natural habitat and in human care.
Wild Diet Primary Vegetation
Capybaras are strict herbivores, functioning primarily as grazers that consume a vast amount of plant material daily. An adult capybara can eat approximately 6 to 8 pounds of fresh grass in a single day, which forms the bulk of their diet. They are selective feeders, preferring young, tender grasses and soft aquatic reeds over older, tougher vegetation that contains more lignin. This preference allows them to maximize nutrient intake from the most digestible parts of the available forage.
Their foraging patterns are strongly influenced by seasonal shifts in their native environment. During the wet season, when fresh grasses are abundant and high in nutritional value, capybaras feed almost exclusively on the lush terrestrial vegetation. As the dry season arrives and water sources recede, the available grasses dry out and lose nutritional content. This scarcity forces the capybara to become less selective, consuming a wider variety of plants, including less palatable reeds, grains, and even tree bark and shoots to survive.
Digestive Adaptations for Nutrition
Breaking down the cellulose-rich grasses that make up their diet requires a highly specialized digestive system, which is why capybaras are classified as hindgut fermenters. They possess an enlarged cecum, a pouch located at the junction of the small and large intestines, that acts as a fermentation chamber. The cecum can account for up to three-quarters of their entire gastrointestinal tract volume. Within this chamber, dense populations of microorganisms break down plant molecules, such as cellulose, into volatile fatty acids that the capybara can absorb and use for energy.
Because the microbial fermentation occurs past the small intestine, capybaras employ a behavioral adaptation called coprophagy. This involves consuming their own feces, specifically a nutrient-rich type known as cecotropes. By re-ingesting this partially digested material, they gain a second opportunity to absorb the essential nutrients, proteins, and B vitamins synthesized by the microorganisms. This recycling mechanism significantly increases their digestive efficiency, allowing them to thrive on a high-fiber, low-nutrient diet.
Water Needs and Aquatic Food Sources
Capybaras have a close relationship with water, which is necessary for both their hydration and their diet. They must remain near water sources to keep their skin moist, regulate their body temperature, and evade predators. The moisture content of their diet is important, and consuming fresh, water-rich plants helps to meet their daily hydration needs.
While terrestrial grasses are their primary food source, the capybara’s semi-aquatic nature allows them to supplement their diet with aquatic plants. They are proficient swimmers and consume various submerged and floating vegetation, such as water hyacinths and reeds. This reliance on aquatic plants becomes pronounced during the dry season, when land-based grasses become scarce. These aquatic food sources provide a more consistent alternative, supplying both moisture and nutrients.
Capybara Diet in Captivity
The capybara diet shifts significantly when the animals are housed in zoos or as pets, transitioning from constant grazing to a structured feeding plan. In captivity, their diet is typically built around specialized commercial rodent or guinea pig pellets. These pellets are formulated to be high in fiber and low in starch, mimicking the nutritional profile of the grasses they consume in the wild. A continuous supply of high-quality hay, such as timothy or orchard grass, is provided to promote healthy digestion and ensure continuous tooth wear.
Fresh vegetables and limited amounts of fruit are added as supplements, though sugary foods must be strictly moderated to prevent digestive issues. Capybaras cannot synthesize their own Vitamin C, similar to their relative the guinea pig. Therefore, their captive diet must include a source of this vitamin, either through fresh greens, a specific pellet formulation, or a dietary supplement, to prevent the development of scurvy. Continuous access to clean drinking water is necessary to support their digestive processes and overall health.