Coypus

Coypu, or nutria, Myocastor coypus, is a large semiaquatic rodent native to the wetlands of Argentina, Brazil, Chile, Paraguay, and Uruguay. It has been widely introduced outside its native range for fur farming and, in some areas, has established wild populations. The species is listed as Least Concern by the IUCN.

Physically, the coypu has a chunky body, dense brown fur, small rounded ears, and a long, naked tail that is laterally flattened and used for swimming. It possesses webbed hind feet and incisors adapted for gnawing vegetation. Its senses are well-suited to life along rivers and marshes.

Habitat includes freshwater wetlands, rivers, marshes, and floodplains. Coypus feed primarily on grasses and submerged aquatic plants, but also consume bark and crops. They are strong swimmers and may construct burrows or lodges in banks and vegetation near water.

Breeding is fast; females give birth to multiple litters each year, with litter sizes varying by season and region. Young are independent after a few months.

In nonnative regions, coypus are considered pests due to crop damage, bank erosion, and competition with native herbivores. They have caused ecological changes in wetlands and are targeted by trapping, hunting, and habitat modification to reduce populations. In some areas, restoration and monitoring programs aim to balance ecosystems.