Where Do Beavers Live?

Beavers live in rivers, lakes, ponds, marshes, and low-gradient streams. They prefer areas with many trees and shrubs that they can eat and use to build dams.

You might think beavers would avoid urban streams. However, urban streams often provide the perfect home for beavers. Most city streams have gentle slopes and slow-moving water, which makes it easier for beavers to build and maintain their dams. From a beaver's point of view, roads act like large manmade dams with small openings called culverts. This is why beavers often choose undersized culverts as the first place to build their dams.

What Do Beavers Eat?

Beavers are vegetarians. They mainly eat the cambium of trees, which is the layer just beneath the bark, along with leaves and twigs from trees and shrubs. They also enjoy aquatic plants, grasses, rushes, sedges, and other herbs. Like many plant-eating animals, beavers eat a variety of plants, choosing different ones at different times of the year.

When it comes to trees and shrubs, beavers prefer native species such as willow, black cottonwood, Oregon ash, red-osier dogwood, and bigleaf maple. If their favorite native plants are not available, they will also eat ornamental plants and some crops.

How Big Will a Beaver Colony Get?

A beaver colony, also known as a family, can have anywhere from two to twelve members. Each colony includes a breeding pair and their young from the current and previous year. Beavers reproduce once a year in the spring, with each litter containing one to eight young, called kits. Beaver families are very territorial and will not allow other beavers to enter their area. Young beavers usually leave their family around the age of two to find their own territory.

Why Do Beavers Build Dams?

Beavers are quick and agile in the water, but they are slow and vulnerable on land. This is why they rarely venture far from the water's edge. Beavers build dams and canals to create deep water, which protects them from predators and provides easy access to food. They also create safe underwater entrances to their homes. Often called "nature's engineers," beavers are the only animals, besides humans, that significantly change their environment to meet their needs.

Beavers typically build their dams in low-lying areas with shallow, flowing water during dry months when rainfall is low. The sound and feel of flowing water encourage beavers to build or repair their dams. They use natural or manmade objects, such as stones, culverts, or tree stumps, to support their dams. Once built, beavers maintain their dams to keep water levels high, allowing them to access food and materials without traveling far on land.

Do All Beavers Build Dams?

No, not all beavers build dams. In places with plenty of deep water, like the Willamette River, beavers do not need to build dams. Instead, they may dig a den in a high bank or build a lodge if digging is not possible.