American Beaver

More Information

American beavers are brown, semiaquatic rodents that can weigh up to 70 pounds and reach 4 feet in length. Their tail can be 10 inches long and 6 inches wide. They are adapted to life in the water thanks to webbed hind feet, a muscular body, and a naturally oily and waterproof outer fur layer. Their ears and nose can close when underwater and they have a nictitating membrane, or a third transparent eyelid, that protects their eyes.

These rodents are secretive and nocturnal. Colonies are made up of a monogamous adult pair and their offspring. They will build lodges out of branches and mud, which are often only accessible from underwater. Breeding generally occurs in January and February, with three or four kits born in the late spring months. Kits are born with their eyes open and can swim immediately. They will stay with their family for up to two years.

Did You Know?

• Beavers are the largest rodents in North America and one of the largest rodents in the world (South American capybaras are bigger).
• Beavers are second only to humans in their ability to manipulate their environment. They are well known for felling trees, which they do with strong front teeth and a heavy jaw. Their large claws help them dig. And the dams they build provide habitats for a wide range of other animals.
• Beavers were hunted aggressively in the 19th century. In fact, the demand for their pelts were cited as a driving factor for European westward expansion across North America. Hunting is now regulated, and beaver populations have made a massive comeback.