American Beaver

The North American Beaver (Castor canadensis) is a large semi-aquatic rodent native to Canada. Also it is native to most of the United States and parts of northern Mexico. Its fur is dark brown. It has a rounded head, a large flat paddle-shaped tail and webbed hind feet. The unwebbed front paws are smaller, with claws. This is the largest rodent found in North America and the second largest rodent in the world (the largest rodent being the South American capybara).

Beavers are mainly active at night. They are excellent swimmers but are more vulnerable on land. They tend to remain in the water as much as possible. They are able to remain submerged for up to 15 minutes. A scent gland near their genitals secretes is an oily substance known as castoreum. It is used to waterproof its fur. A thick layer of fat under its skin insulates the beaver from its cold water environment. The eyes are covered by a nictitating membrane, which allows the beaver to see underwater. Their nostrils and ears are sealed while submerged.

They sometimes make their home in a riverbank. They are best known for building dams across streams and constructing their “lodge” in the artificial pond which forms. The entrance to the lodge or burrow is located underwater. In the event of danger, a beaver slaps its tail on the water to warn other family members.

Research has shown that dam-building behavior and choice of dam location is triggered by the sound of flowing water.

The dam is constructed using sections of deciduous trees. They use birch, aspen, and willow. Vegetation is also an important part of the beaver’s diet. The trees are cut down using their strong incisor teeth. Their front paws are used for digging and carrying and placing materials.

During the summer, beavers also eat grasses, cattails, water lilies and other aquatic plants.

Besides providing a safe home for the beaver, beaver ponds also provide habitat for waterfowl and other aquatic animals. Their dams help reduce soil erosion and can help reduce flooding.

Beavers usually mate for life. The young beaver “kits” typically remain with their parents for up to two years.


These animals are considered pests in some parts of their range because their dams can cause flooding in nearby areas. They are incredibly persistent in repairing any damage to the dam. The only way to make them stop is to remove them from the location.

These animals are often trapped for their fur. Predators include the Coyote, the Gray Wolf, the Bobcat and the Red Fox.