American Beaver

Jeff Foott/DCI

The beaver, the second largest rodent in the world (the capybara is the largest), is well known for its wide, flat tail, which it slaps on the surface of the water to warn other beavers of approaching danger.

It lives in colonies with four to eight other family members and marks its territory with scent mounds — piles of mud that it scents with glandular secretions.

Sometimes it resides in a burrow at the water's edge; more often it lives in a dome-shaped lodge, which it builds with branches and trees cut down with its large incisors.

The trees yield bark and leaves, favored foods in winter. In summer it also feeds on other vegetation, especially aquatic plants.

It makes dams to flood areas and bring the trees closer to the water, where it is most comfortable.

A secretive and nocturnal creature, it is awkward on land and thus vulnerable to predators.

Animal Facts

Name: American Beaver (Castor canadensis)

Family: Castoridae (Beavers)

Range: Canada and United States

Habitat: Streams and lakes in forests

Diet: Bark, cambium, leaves, twigs, roots, shoots, and buds

Head and Body Length: 27 to 43 inches (70 to 110 cm)

Tail Length: 10 to 16 inches (25 to 40 cm)

Weight: 31 to 59 pounds (14 to 27 kg)

Life Cycle: Mating January to February; gestation 105 to 120 days, usually three to five kits born

Description: Yellowish-brown to black coat; large front teeth; long whiskers; large, black, webbed feet; powerful hind legs; broad, flat tail with large, blackish scales

Conservation Status: Common