The capybara (Hydrochoerus hydrochaeris) is the world’s largest living rodent, native to South America. Weighing up to 66 kilograms (about 146 pounds) and standing roughly 60 centimeters (2 feet) at the shoulder, capybaras are semi-aquatic mammals closely related to guinea pigs and rock cavies. They inhabit wetlands, savannas, and riverbanks across much of the continent, where they play a key role in ecosystems as grazers and prey species. This profile breaks down their size, physiology, behavior, and how they compare to other large rodents commonly cited as contenders.
Size and Physical Traits
Capybaras are substantially larger than any other rodent species that remains widely recognized today. Their size supports semi-aquatic habits, with webbed feet and dense, water-repellent fur. Sexual dimorphism is modest, with females often slightly larger than males.
Metric and Imperial Range
| Measure | Typical Range | Maximum Recorded |
|---|---|---|
| Body Length | 100–130 cm (39–51 in) | up to 150 cm (59 in) |
| Shoulder Height | 50–60 cm (20–24 in) | about 66 cm (26 in) |
| Weight | 35–55 kg (77–121 lb) | up to 66 kg (146 lb) |
Closest Relatives and Comparisons
Within the order Rodentia, capybaras are part of the family Caviidae. Their closest living relatives are guinea pigs, followed by rock cavies and agoutis. Below is a concise comparison with other notably large rodents to clarify how capybaras stand out.
- Capybara: up to 66 kg; semi-aquatic; webbed feet; social herd life
- Beaver: typically 20–30 kg; semiaquatic; strong tail for dam building; solitary to small family groups
- Brazilian guinea pig (largest cavy): about 4 kg; terrestrial; no webbing; social burrowers
- Paca: around 6–14 kg; terrestrial; spotted coat; mostly solitary
Native Range and Habitat
Capybaras are found across much of northern and central South America. They depend on stable water sources and varied vegetation for food and refuge.
| Country or Region | Typical Habitat | Conservation Status |
|---|---|---|
| Amazon Basin | Rivers, lakes, flooded forests | Least Concern (wide, stable populations) |
| Cerrado and Pantanal | Seasonal wetlands, savannas | Locally hunted, generally stable |
| Orinoco Basin | River edges, llanos wetlands | Variable local density |
Behavior and Social Structure
Capybaras are highly social and live in groups that can range from a few individuals to more than 20, though 10–20 is typical. Groups usually consist of related females, their offspring, and one or more adult males. They communicate using a range of vocalizations, scent markings, and physical signals. Resting and feeding often occur in water, which provides refuge from predators.
Daily Activity and Diet
They are crepuscular and often graze at dawn and dusk, but can also feed during the day when undisturbed. Grasses make up the bulk of their diet, and they also consume aquatic plants, fruit, and bark. Their digestive system is adapted to extract nutrients from fibrous plant material, similar to ruminants though less complex.
Reproduction and Lifecycle
Breeding can occur year-round where conditions are favorable, often linked to rainfall patterns. After a gestation of about 150–180 days, a typical litter numbers four to five pups, though larger litters are possible. Pups are precocial, beginning to graze within days and swimming within hours. Females nurse for several weeks; males sometimes assist in guarding young.
Human Interactions and Management
Capybaras are hunted for meat and skin in parts of their range, and they can come into conflict with agricultural interests near wetlands. They are also kept in informal settings and increasingly in accredited facilities, where space, water quality, and social groupings are key welfare considerations. In regions like parts of Colombia and Venezuela, regulated hunting and ranching programs aim to balance use and conservation.
Commonly Asked Questions
- Are capybaras rodents? Yes, they are the largest rodents alive today.
- Can capybaras swim? Yes, they are strong swimmers and spend much time in water.
- Do capybaras have natural predators? Yes, including jaguars, caimans, anacondas, and large birds of prey.
- Are capybaras domesticated? They are not domesticated in the same sense as dogs or livestock but can be tamed where habituated to humans.
- How do capybaras stay warm in cooler regions? They rely on shelter, group huddling, and access to warmer microhabitats; in cooler climates they are often kept in protected enclosures.
Key Takeaways
Capybaras are the definitive largest rodents, distinguished by size, webbed feet, and semi-aquatic adaptations. They form cohesive social groups, rely on wetlands, and play an important ecological role as grazers. Understanding their biology and habitat needs helps distinguish them from other large rodents and underscores the importance of conserving the freshwater ecosystems they depend on.