The capybara, the world’s largest rodent, is a semi-aquatic herbivore whose diet is intrinsically linked to its habitat and behavior. Its feeding habits reflect a specialized strategy to thrive on a high-fiber, low-nutrient plant-based diet. This specialization governs their daily routine, dental structure, and social interactions near water sources. Understanding what they consume, both in the wild and in captivity, is essential.
Primary Diet of Wild Capybaras
Capybaras are specialized grazers, with their natural diet consisting almost entirely of grasses and aquatic vegetation found near the rivers, ponds, and marshes of their South American range. During the lush wet season, they are selective, preferring the most palatable and nutritious grasses and sedges. Over 70% of a capybara’s diet can come from just a few types of plants, such as switchgrass, crowngrass, and Bermuda grass.
An adult capybara typically consumes between 6 to 8 pounds of grass daily. This continuous intake is required to meet their energy needs from the low-calorie, high-fiber plants they eat. During the dry season, when fresh grasses become scarce, they become opportunistic feeders. They diversify their diet to include less palatable items like reeds, barks, grains, and roots, though fibrous grasses remain the staple.
Digestive Behavior and Processing Food
To process the tough, fibrous plant material they consume, capybaras are hindgut fermenters. The bulk of their food breakdown occurs in an enlarged cecum and colon, where beneficial bacteria break down cellulose. A defining feature of their digestion is coprophagy, the re-ingestion of their own feces. They consume a specific soft fecal pellet, called a cecotrope, produced after initial fermentation. This allows them to re-process the material and absorb protein, B vitamins, and other nutrients synthesized by gut microbes.
The capybara’s constantly growing, open-rooted cheek teeth and incisors are a physical adaptation to their abrasive diet. The continuous chewing required to process large quantities of silica-containing grasses naturally wears down the teeth. This continuous growth ensures the teeth do not wear away completely, which is necessary for an animal that grazes constantly.
Managing the Captive Capybara Diet
The captive capybara diet must replicate the high-fiber, low-calorie profile of their wild forage. The foundation is high-quality hay, such as Timothy or Bermuda grass hay, offered freely (ad libitum) for proper gut function and dental wear. Fresh, untreated grass should also be provided to mimic natural grazing behavior.
Capybaras cannot synthesize their own Vitamin C, so supplementation is mandatory when fresh forage is unavailable. This is achieved using a specific vitamin C supplement or fortified commercial rodent chow. Pellets are provided in limited quantities to ensure the animals prioritize the high-fiber hay. A mineralized salt block is sometimes provided for adequate intake of trace minerals. Maintaining this high-fiber diet is paramount, as a lack of roughage disrupts the balance of their hindgut fermentation system.
Toxic and Unsuitable Foods
A capybara’s digestive system is highly sensitive to foods that deviate from its natural fibrous diet. Foods high in sugar or starch are unsuitable because capybaras cannot efficiently process them. Excessive sugar causes rapid fermentation in the gut, leading to painful bloating and potentially fatal digestive upsets. Therefore, human foods, especially sweetened items like candy or junk food, must be strictly avoided. Even fruits and sweet vegetables should be given only in very small, occasional amounts due to their sugar content.