Beavers are nocturnal semi-aquatic rodents. They are the second largest rodent in the world. There are two types of beaver: American and Eurasian. They live in freshwater lakes, ponds, rivers and streams, usually near woodlands.
They live in family units called colonies that are made up of adults, yearlings and kits. Adult beavers usually weight 35 to 60 pounds. They are 3 to 4 feet long. Males and females look alike, both having dark brown fur. They have a large flat tale, webbed hind feet, and bright orange teeth that don’t stop growing. Beavers use their tails in three ways: a prop when sitting or standing up, a rudder for swimming, and to slap the water to warn others of danger.
Beavers’ favorite foods include leaves and green bark (cambium) from aspen and other fast-growing trees, plus water lily tubers, clover, and apples. Beaver pruning stimulates willows, cottonwood and aspen to grow bushier the next spring.
Dams built by a colony of beaver also help slow the flow of floodwaters and help control erosion. The dam serves keeps a beaver lodge entrance and food storage area under water. Eurasian beavers, however, don’t always build lodges—sometimes they dig burrows in stream banks—the entrance is also underwater. Beavers mark their territory with "scent mounds" — piles of mud and sticks that the beaver coats in musk oil.
Fun Beaver Facts
- Water downstream of North American beaver dams is cleaner.
- Beavers mate for life.
- A beaver can remain submerged in the water for up to 15 minutes.
- The beaver waterproofs its thick fur by coating it with castoreum, an oily secretion from its scent glands.
- Beavers can close both their ears and nose.
- Beavers were hunted to extinction in England in the 12th century.
Beavers: Wetlands and Wildlife
Missouri Botanical Garden
Nature Works, New Hampshire Public Television