Capybaras, the world’s largest rodents, are native to South America and well-adapted to their semi-aquatic habitats, spending much of their lives in or near water. This influences their feeding habits. Understanding their diet provides insight into how these herbivores thrive in diverse South American ecosystems, reflecting their specific adaptations and available resources.
The Core Diet of Capybaras
The majority of a capybara’s diet consists of various grasses and aquatic vegetation. They are specialized grazers, primarily consuming monocotyledonous plants abundant in the wetlands, savannas, and riverbanks where they live. Specific examples include Bermuda grass (Cynodon dactylon) and Panic grass (Panicum spp.). Their unique dental structure, featuring continuously growing incisors and wide, flat molars, is well-suited for efficiently grinding tough plant fibers. This allows them to process the large quantities of vegetation needed for their size.
Capybaras typically graze on land during the cooler parts of the day and often forage in water, consuming submerged or emergent vegetation like water hyacinths (Eichhornia crassipes) and water lettuce (Pistia stratiotes). The constant availability of these plants makes them a reliable and abundant food source for such a large herbivore. An adult capybara can consume between 6 to 8 pounds (approximately 2.7 to 3.6 kilograms) of fresh grass daily. This consistent access to fibrous plant material is crucial for their nutritional needs and body mass.
Their reliance on grasses and aquatic plants reflects their evolutionary adaptation. These plants provide the bulk of the carbohydrates and cellulose necessary for their energy requirements. A significant portion, up to 70%, comes from just a few plant species such as sedges, switchgrass, Bermuda grass, and crowngrass. The high fiber content of their primary food sources also plays a significant role in their specialized digestive process, requiring specific physiological adaptations to extract maximum nutrition.
Supplemental Foods and Seasonal Variations
While grasses form the bedrock of their diet, capybaras also incorporate other plant materials, particularly when primary food sources become scarce, such as during dry seasons when fresh grasses are less available. They may broaden their diet to include tougher vegetation such as tree bark, shrubs, reeds, grains, melons, and squashes. This adaptability helps them survive environmental stress.
The specific types of supplemental foods vary based on regional flora and seasonal conditions. For instance, capybaras might consume fallen fruits, which offer a more concentrated source of sugars. However, fruits are typically consumed sparingly due to their sugar content. The consumption of bark can be observed when other vegetation is sparse. These dietary shifts demonstrate their opportunistic feeding behavior.
Their ability to switch to available food sources highlights their resilience. These supplemental foods rarely constitute a significant portion of their overall intake. They serve as a buffer, ensuring survival when preferred grasses and aquatic plants are less abundant. This dietary flexibility contributes to their widespread distribution.
How Capybaras Digest Their Food
Capybaras possess a specialized hindgut fermentation digestive system, allowing them to efficiently process their fibrous, plant-based diet. Similar to horses, they rely on a large cecum and colon where microbial fermentation occurs. This process breaks down cellulose and other complex carbohydrates into volatile fatty acids, which the capybara can then absorb and use for energy. This adaptation is essential for extracting nutrients from tough plant material that would otherwise be indigestible for many other animals. The immense surface area of their hindgut facilitates extensive microbial activity.
A notable aspect of their digestion is coprophagy. Capybaras produce two types of fecal pellets: soft, nutrient-rich pellets (known as cecotropes) and harder, more fibrous ones. The soft pellets are rich in partially digested plant matter, beneficial microbes, and essential nutrients like B vitamins and proteins synthesized by gut bacteria in the hindgut. By consuming these specific pellets, they re-digest their food, allowing for a second pass at nutrient absorption.
This practice maximizes nutrient absorption. Coprophagy ensures that capybaras extract the maximum possible nutritional value from their high-fiber diet, which is otherwise difficult to process efficiently. This unique digestive strategy is an adaptation that enables them to thrive on a diet primarily composed of low-nutrient grasses and aquatic plants, supporting their large body size and metabolic demands.