Capybaras, the world’s largest rodents, are semi-aquatic mammals known for their calm and social nature. Their unique characteristics often lead many to wonder about their presence in various parts of the globe, including the distant continent of Australia.
The Capybara’s Native Range
Capybaras are not native to Australia and are not found in the wild. Their natural habitat is exclusively within Central and South America, spanning countries like Brazil, Venezuela, Colombia, Peru, Paraguay, Uruguay, Panama, and northeast Argentina. These semi-aquatic rodents thrive in environments with readily available water, inhabiting savannas, forests, and areas near lakes, rivers, swamps, ponds, and marshes.
Highly adapted to watery homes, they possess partially webbed feet for swimming and can hold their breath underwater for up to five minutes to evade predators. Capybaras are also social creatures, living in groups of 10 to 20 individuals, although larger gatherings of up to 50 or even 100 can occur around dwindling water sources during dry seasons. Australia maintains rigorous biosecurity laws to safeguard its unique ecosystems from non-native species, preventing capybaras from establishing in the wild.
Australia’s Unique Rodents
While capybaras do not roam wild in Australia, the continent is home to a diverse array of native rodent species, all belonging to the Muridae family. These Australian rodents have adapted to the continent’s varied environments, from arid deserts to lush wetlands. Their evolutionary history includes “Old endemics” and “New endemics,” reflecting different waves of colonization from Asia.
Water Rat (Rakali)
The Water Rat, also known as Rakali (Hydromys chrysogaster), is one of Australia’s largest native rodents. Rakali are semi-aquatic, found near permanent fresh or brackish water bodies, possessing webbed hind feet and a waterproof coat for an aquatic lifestyle. Primarily nocturnal, they prey on insects, crustaceans, mussels, fish, and small mammals.
Hopping Mice
Hopping Mice (Notomys genus) include about ten types adapted to Australia’s arid and desert regions. Species like the Spinifex Hopping Mouse (Notomys alexis) and the Dusky Hopping Mouse (Notomys fuscus) are nocturnal, sheltering in deep burrows during the day. These mice obtain moisture from their diet of seeds, berries, and insects, eliminating the need to drink water.
Tree Rats and Bush Rats
Australia also hosts native Tree Rats, such as the Black-footed Tree-rat (Mesembriomys gouldii) and the Golden-backed Tree-rat (Mesembriomys macrurus). These nocturnal, arboreal rodents inhabit tree hollows or dense foliage in northern Australian woodlands. The Bush Rat (Rattus fuscipes) is a native omnivorous rodent found in forests, woodlands, and heath, preferring dense undergrowth for shelter.