Capybaras are large, semi-aquatic mammals native to South America. They inhabit savannas and dense forests, always remaining close to bodies of water like rivers, lakes, and marshes. This highly social animal has gained considerable attention for its size, which far exceeds that of any other rodent species. The capybara’s reputation as the world’s largest rodent is well-deserved.
The World’s Largest Rodent
The Greater Capybara, scientifically known as Hydrochoerus hydrochaeris, is the species known for its record dimensions. An average adult H. hydrochaeris stands about 50 to 62 centimeters (20 to 24 inches) tall at the shoulder. They reach a length of 106 to 134 centimeters (3.5 to 4.4 feet).
The standard weight range for adult capybaras falls between 35 and 66 kilograms (77 to 146 pounds). The largest capybara ever recorded was a wild female specimen from Brazil, documented at a remarkable 91 kilograms (201 pounds). Other exceptional reports have cited individuals reaching up to 105.4 kilograms (232 pounds), though the 91-kilogram female is the most frequently cited upper limit for the species.
Defining the Two Capybara Species
The genus Hydrochoerus contains two distinct living species. The Greater Capybara (Hydrochoerus hydrochaeris) is known for its record-breaking dimensions and wide distribution across most of South America. This is the species that reaches the enormous weights and lengths previously described.
The second species is the Lesser Capybara (Hydrochoerus isthmius), which is noticeably smaller. This relative is geographically restricted, found only in a narrow range extending from central Panama through northwestern Colombia and Venezuela. The Lesser Capybara generally reaches a maximum weight of about 28 kilograms (62 pounds) and a length of roughly one meter (3 feet).
Factors Influencing Capybara Size
Individual size variation in Greater Capybaras is influenced by genetics, sex, and environmental conditions. Females of the species tend to be slightly heavier than males, a subtle form of sexual dimorphism. The largest recorded individuals are often females.
Diet quality plays a major role in determining an individual’s final size, as capybaras are selective grazers. Those living in environments with abundant, high-quality aquatic grasses and vegetation are more likely to achieve greater body mass. Size can also fluctuate seasonally, with individuals sometimes losing weight during the dry season when food resources become less nutritious and more scarce.