American Beaver

Castor Canadensis
Conservation Status: Least Concern


  • They typically weight from 24 to 70.7 pounds and are 29 to 35 inches long. Their tail adds another 8 to 14 inches to its length.
  • They have webbed hind feet and large, flat, nearly hairless tail.
  • They have two separate layers of coats. The top portion of the coat is coarse and thick, offering defensive benefits.

Lifespan: Average lifespan for a beaver in the wild is about 24 years.

Range and Habitat:

  • They live in or around freshwater ponds like lakes, rivers, marshes, and swamps except in the desert areas of the Southwest United States.
  • Beaver colonies create dams of wood and mud to provide still, deep water in order to protect against predators such as wolves, coyotes, bears, or bald eagles.
  • They float materials to their homes.
  • Their homes are called lodges and they are made from mud and branches.
  • Lodges are positioned in the middle of the pond, with a hidden entrance (from the water), which prevents predators to even get in touch with them.

American Beaver Range


  • Beavers are semi-aquatic herbivores. This means they obtain some food in water and some on land.
  • Most of their diet is made up of tree bark and cambium. Cambium is the soft tissue that grows under the bark of a tree.
  • They especially like willow, maple, birch, aspen, cottonwood, beech, poplar, and elder trees.
  • They also eat vegetation like roots, buds, and other water plants.


  • Famously busy, they turn their talents to reengineering the landscape around them.
  • Beavers are very social and live in groups called colonies.
  • Beavers are monogamous and mate for life or until a partner dies.
  • Beavers are mainly nocturnal, doing their work and hunting at night.

Fun Facts:

  • Beavers are the second largest rodent in the world after the capybara.
  • Beavers are second only to humans in their ability to manipulate and change their environment.
  • Beavers can stay under water for 15 minutes without coming to the surface. They have transparent eyelids that act as goggles so they can see as they swim.

Keeper Notes:

Finn was born May 1, 2010 and daughter Shiloh on July 16, 2015 at Zoo Montana in Billings, Montana.