The large rodents called beavers are known for using their teeth and paws to build lodges, storehouses, dams, and canals. Beavers are amphibious, which means they are able to live both in water and on land.

Where beavers live

Beavers are native to North America, Europe, and Asia. Today they are found mostly in the northern wooded regions of North America and Europe. Beavers live most of their lives in or near water. They settle along banks of streams, rivers, and lakes bordered by woodland.

Physical features

Beavers are the largest rodents in North America and the second largest in the world after the capybara of South America. An adult beaver may grow to be about 4 feet (1.3 meters) long, including its tail. It may weigh more than 60 pounds (27 kilograms).

A beaver's thick body is covered with a coat of long, reddish-brown outer hairs and soft, dense, brown underfur. This warm, waterproof coat allows the beaver to swim in icy water in the wintertime. Most of a beaver's features—the fur, toes, tail, ears, nose, and lips—allow the animal to live in the water as well as on land. For example, beavers have ears and a nose that are equipped with valves that close when the animal swims underwater. In addition, a beaver's lips close behind its big front teeth so the animal can cut wood and branches underwater. Because of these features, a beaver may remain underwater for up to 15 minutes.

A beaver's front feet are small and look much like a human hand. Beavers use their hands to pick up and carry objects. The tail is scaly, flat, and shaped like a paddle. A beaver uses its tail to warn other beavers of danger by slapping it on the water's surface and making a loud noise.

Behavior

Beavers are nocturnal, which means that they do most of their building and food gathering at night. Beavers eat fresh green bark and the buds, leaves, and twigs of certain trees. In the summer they also eat water plants, berries, swampwood, and fruit.

Beavers are social animals that live and work together. Large groups of beavers build dams in narrow, shallow parts of streams. The beavers begin by gnawing down a number of young trees. They drag these trees to the dam site and bury them in mud. Into this foundation the beavers fit and pile more young trees, adding mud and stones until a strong barrier is completed. Sometimes the beavers build canals to help move logs that are too heavy to drag overland.

The artificial pond created by the dam is where the beavers make their storehouses and permanent homes, or lodges. A lodge is usually the work of a pair of beavers. It is made up of a platform of carefully interlaced branches held together by clay and dead leaves. A dome-shaped roof covers the platform. The lodge may be more than 5 feet (1.5 meters) high. Entrances to the lodge often open underwater. This allows the animals to pass in and out below the winter ice. Another entrance is used for bringing in wood for food. A lodge may be home to as many as eight animals, including an adult pair and two sets of offspring.

Life cycle

Beavers usually mate with the same partner for life. The female is pregnant for about 105 days before giving birth to her young, which are called kits. A litter includes one to nine kits, with four being the most common size. Kits learn to swim when they are only a month old. Beavers may live as long as 19 years.

Beavers and humans

Beavers have been hunted for their fur, their tails, and their musk glands. Musk glands are scent glands at the rear of a beaver's body that produce a liquid used to make perfumes. During the 17th, 18th, and early 19th centuries, beaver skins were an important part of the world's fur trade. In fact, much of the exploration of North America was prompted by the search for beaver fur. Beginning in the 20th century, however, conservation laws were passed to protect beavers throughout the world. As a result, beavers have been saved and resettled in areas where they had once been common.