Nutria

The South American coypu are also called nutria or coypu. They look like a cross between a beaver and a muskrat.

Characteristics

What do swamp beavers look like?

Despite their name, swamp beavers, these animals are neither beavers nor muskrats. Rather, they are related to guinea pigs and belong to the coypu family and thus to the rodents. Marsh beavers are 43 to 64 centimeters long from the tip of the nose to the bottom, the tail measures 25 to 42 centimeters. They weigh up to nine kilograms.

Their physique resembles that of a beaver or a large muskrat: the head is long and has a blunt snout with long whiskers. The neck is short and thick, the ears are small. The males of the coypu are usually larger than the females. Marsh beavers have webs between the five toes of their hind feet as a sign of their adaptation to life in the water. Also, unlike the beaver, which has a flat, broad tail, the swamp beaver’s tail is rounded and bare.

Like all rodents, coypu has large fangs that are covered with a protective orange layer and grow back throughout life. The coypu’s fur is reddish-brown and has velvety soft undercoats and long, rough topcoats. Because of their fur, coypu is popular as fur animals and is bred on farms. Breeding also resulted in other coat colors, for example, the bright white coat.

Where do swamp beavers live?

Swamp beavers come from South America. They live in Bolivia, southern Brazil, Chile, and Argentina. There they are not at home in the tropical, but in the temperate climate zones. Today they are bred in fur farms around the world. However, they also occur in the wild: Some of them were abandoned, some of the animals escaped from fur farms and multiplied. In southern France, they have even been released into fishponds to keep them free from overgrowth.

Where does coypu live?

Marsh beavers live in rivers and streams whose banks are densely overgrown and where aquatic plants grow in abundance. In Europe and North America, coypu can only survive in regions where winters are mild and waters rarely freeze over. In Germany, they are most likely to be found on the Upper Rhine and Kaiserstuhl. They hardly survive harsh winters in which the water freezes over.

What species of coypu are there?

Within the coypu family, the coypu is the only genus and species. They are most closely related to the port rats and the tree and piglet rats, all of which also live in South America.

How old do swamp beavers get?

Marsh beavers live about six to ten years.

Behave

How do swamp beavers live?

Coypu is a very elegant swimmer: Their movements in the water are reminiscent of those of an otter. That’s where their Spanish name “Nutria” comes from, which means nothing else than “otter”. They are not very good at diving, but they can stay underwater for up to ten minutes without having to take a breath.

Marsh beavers are mainly active at dusk and at night. Then they are busy with the search for food and personal hygiene. They sit down, comb their fur with their claws and grease it with fat from special glands at the corners of their mouths. During the day they rest in their burrows, which they build in the embankment. These tunnels are fairly short and have no side passages.

Unlike the burrows of the European beaver, the entrance to the swamp beaver burrows is always above and not underwater. Sometimes cyber just build nests out of reeds on the shore. Marsh beavers live in small colonies. Up to 13 animals live together there.

Mostly they are adult females who are related to each other, as well as their offspring and a large male. Young male coypu often lives alone. Marsh beavers are quite defensive: if they feel threatened, they bite down hard with their large incisor teeth.

Friends and foes of coypu

Otters, badgers, or other large martens can be dangerous to the marsh beavers. Brown bears, wolves, lynxes, and foxes are also among their enemies. However, one of the biggest enemies of the coypu was a man: in the 19th century, the animals were hunted so hard for their fur that some of them had to be protected. Eventually, however, people began to breed them on farms.

How does coypu reproduce?

A female swamp beaver can have seven, sometimes even up to 13 young. After mating, it takes 130 days for the little coypu to be born. That’s quite a long gestation period – but the swamp beaver babies are already well developed for that. When they are born, they are completely hairy and their eyes are already open. Just a few hours after birth, they venture into the water and can swim.