9 South American Rodents You Should Know About

South America is home to a diverse range of rodents, from giant, water-loving creatures to small, burrowing specialists. While rodents often go unnoticed compared to larger mammals, they play vital roles in their ecosystems, from dispersing seeds to maintaining healthy wetland environments. Some are surprisingly large, while others are elusive and rarely seen.

In this article, we’ll explore nine fascinating South American rodents you should know about. Whether they’re famous for their size, behaviour, or unique adaptations, these rodents are an essential part of the continent’s wildlife.

1. Capybara (Hydrochoerus hydrochaeris)

We may be biased, but our top pick is the capybara! As the largest rodent in the world, the capybara is an iconic South American species. These social, semi-aquatic mammals are found near lakes, rivers, and wetlands, where they thrive in large groups. With their webbed feet, excellent swimming abilities, and relaxed nature, capybaras have won over the hearts of animal lovers worldwide. Despite their large size, they are gentle herbivores that graze on grasses and aquatic plants.

Capybaras are highly adaptable and can be found in many parts of South America, particularly in Brazil, Argentina, Venezuela, Costa Rica and Colombia. They are known for their peaceful interactions with other animals, often sharing their space with birds, turtles, and even caimans. Their ability to remain calm and social makes them one of the most beloved rodents on the planet.

2. Pacarana (Dinomys branickii)

The pacarana is a rare and slow-moving rodent that belongs to an ancient family of rodents once much more widespread. Despite its large size—it can weigh up to 15 pounds—it is still much smaller than the capybara. Found in the Andean rainforests of Colombia, Ecuador, and Peru, the pacarana is nocturnal and primarily eats fruit, leaves, and stems. Unlike many rodents, it moves slowly and deliberately, often using its front paws to grasp food.

Due to its limited range and low population density, the pacarana is considered a vulnerable species. It is also one of the few rodents that can be seen sitting on its hind legs while using its front paws to eat, much like a squirrel. Though little is known about its behaviour in the wild, researchers believe it may live in small family groups.

3. Coypu (Myocastor coypus)

Also known as the nutria, the coypu is a semi-aquatic rodent that closely resembles a beaver but is smaller in size. It has dense, waterproof fur and large, orange teeth that it uses for gnawing on aquatic plants. Coypus are native to wetlands and riverbanks throughout South America, especially in Argentina, Brazil, and Paraguay.

Although they are an important part of their natural ecosystem, coypus have become an invasive species in other parts of the world, including North America and Europe. Their burrowing habits can cause damage to levees and irrigation systems, leading to conflicts with farmers. However, in their native habitat, they play an essential role in maintaining wetland environments.

4. Agouti (Genus Dasyprocta)

Agoutis are small, rabbit-sized rodents with sleek fur and long, slender legs. Unlike most rodents, they are diurnal, meaning they are active during the day. These fast-moving creatures are excellent seed dispersers, helping forests regenerate by burying nuts and seeds that may later sprout into new trees. They are often seen darting through the undergrowth in forests across South America.

Agoutis have an important relationship with Brazil nut trees, as they are one of the few animals capable of cracking open the tree’s tough seed pods. They use their sharp teeth to break into the pods and then store some of the seeds for later. This behaviour helps the trees spread, making agoutis an essential part of their ecosystem.

5. Paca (Genus Cuniculus)

The paca is another large rodent that is closely related to the agouti but is stockier and has distinctive white spots along its dark brown fur. These rodents are nocturnal and prefer dense forests near water sources. They are excellent swimmers and will often dive into the water to escape predators such as jaguars and ocelots.

Pacas have a unique way of communicating through low-pitched growls and grunts. They are highly valued in some regions for their meat, which has led to hunting pressures. However, they continue to thrive in many parts of South America due to their ability to reproduce quickly and adapt to different forest environments.

6. Mountain Viscacha (Genus Lagidium)

Mountain viscachas look like a cross between a rabbit and a squirrel, with long ears and a bushy tail. They inhabit the rocky Andean mountains, living at altitudes of up to 16,000 feet. Their thick fur helps them survive in cold temperatures, and their agility allows them to navigate steep cliffs and rocky landscapes with ease.

Viscachas are social animals that live in colonies, often sunbathing on rocks during the day. They have a diet primarily consisting of grasses and small plants. Their playful nature and ability to leap between rocks make them a fascinating species to observe in the wild.

7. Brazilian Porcupine (Coendou prehensilis)

Unlike the more familiar North American porcupine, the Brazilian porcupine is an arboreal species, meaning it spends most of its time in trees. It has a long, prehensile tail that it uses for balance while climbing. Its body is covered in short, sharp quills that provide protection against predators.

Brazilian porcupines are primarily nocturnal and use their strong teeth to gnaw on fruits, tree bark, and leaves. They are slow-moving but highly skilled climbers, making them well-adapted to life in the rainforest canopy. Their gentle nature and unique appearance make them one of the most interesting rodents in South America.

8. Tuco-Tuco (Genus Ctenomys)

Tuco-tucos are small, burrowing rodents that live underground in tunnels. They are named after the "tuco-tuco" sound they make, which helps them communicate with other members of their colony. These rodents are commonly found in Argentina, Bolivia, and Paraguay, where they prefer grasslands and sandy soils.

Tuco-tucos play an important role in aerating the soil and improving plant growth. However, because they dig extensive tunnel systems, they are sometimes considered pests by farmers. Despite this, their underground lifestyle protects them from many predators, allowing them to thrive in their natural habitat.

9. Patagonian Mara (Dolichotis patagonum)

The Patagonian mara is one of the most unusual rodents in South America. It resembles a cross between a rabbit and a small deer, with long legs and large ears. Found in the grasslands of Argentina, these rodents are built for speed and can run at high speeds to escape predators.

Maras are monogamous and form strong pair bonds, often staying with the same mate for life. They are highly social and live in groups, often using communal burrows for shelter. Their unique appearance and fascinating behaviour make them one of the most intriguing rodents on the continent.

Final Thoughts

South America is home to an incredible variety of rodents, each with its own unique adaptations and ecological importance. From the well-known capybara to the lesser-known pacarana and tuco-tuco, these creatures play essential roles in their ecosystems. Some are skilled swimmers, others are expert climbers, and some are master burrowers, but all of them contribute to the biodiversity of their environments.

By learning more about these remarkable rodents, we can appreciate the diversity of wildlife in South America and the important roles these animals play. Whether you’re a fan of the charismatic capybara or the elusive pacarana, there’s no denying that South America’s rodents are some of the most fascinating creatures on Earth.