MEET OUR NORTH AMERICAN BEAVER

 

Bucky

Misc:

  • Beavers are the largest rodents in the North America and the third largest in the world!
  • Beavers have orange teeth!
  • The largest beaver dam is 2,790 ft (850 m) in length—more than half a mile long—and was discovered via satellite imagery in 2007. It is located on the southern edge of Wood Buffalo National Park in northern Alberta and is twice the width of the Hoover Dam which spans 1,244 ft (379 m).

Description:

Beavers typically weigh between 33 to 70 lbs with the average being about 44 lbs with a body length of 3 1/2 ft. Very old individuals can weigh as much as 99 lbs!

Like the capybara, the beaver is semi-aquatic. The beaver has many traits suited to this lifestyle. It has a large flat paddle-shaped tail and large, webbed hind feet reminiscent of a human diver's swimfins. The unwebbed front paws are smaller, with claws. The eyes are covered by a nictitating membrane which allows the beaver to see underwater. The nostrils and ears are sealed while submerged. A thick layer of fat under its skin insulates the beaver from its cold water environment.

The beaver's fur consists of long, coarse outer hairs and short, fine inner hairs. The fur has a range of colors but usually is dark brown. Scent glands near the genitals secrete an oily substance known as castoreum, which the beaver uses to waterproof its fur.

Predators:

Common natural predators include gray wolves, coyotes, and mountain lions. Less significant predators include bears, which can dig into a lodge, wolverines, river otters, Canadian lynx, bobcats, and mink

Range and Habitat:

Throughout North America, and introduced into South America where it is now considered an invasive species. They are found in ponds, marshes, rivers and wetlands.

Diet:

Bark of such trees as beech, maple, willow birch, alder, and aspen, as well as aquatic vegetation, buds, and roots

Behavior:

Beavers live in colonies of four to eight family members. Considered the best engineers among rodents (and many other animals), beavers construct dams with mud, brush, stones, poles, vegetation, and other materials to create safe lodging and a provide themselves with a good food supply.

Beavers are mainly active at night. They are excellent swimmers but are more vulnerable on land and tend to remain in the water as much as possible. They are able to remain submerged for up to 15 minutes. They use their flat, scaly tail both to signal danger by slapping the surface of the water and as a location for fat storage.

Construction Experts:

Beavers cut trees and drag them to the water to form dams and lodges. Using any rocks or branches lodged underwater or on the bank to build upon, beavers begin adding branches hauled to the water. Lodges are mounds built in the middle of the water, usually not far from the dam. Each lodge has one nesting chamber located above the water's surface and several entrances through underwater channels. Wonderful diggers, beavers may also burrow underground tunnels from the banks up to favorite feeding grounds and excavate channels to other parts of the stream or river. Beavers eagerly maintain their structures by patching them with branches and mud scooped from the floor of the waterway or pool. At times, flooding or storms may destroy lodges and dams, but many withstand the weather.

Eco-engineers:

Beaver dams prevent the normal flow of water, flooding the banks of waterways and creating pond environments. These pools attract many insects, birds, and other creatures that thrive in still water. Certain animals—such as fish that must migrate long distances up or down a river—may not benefit from the beaver's work, and may perish. Flooding caused by the dam may also kill engulfed trees, plants, and insects. But beavers also encourage new life, as they create a marshy area. New insects are attracted to dead wood, and the dampened soil encourages new trees to sprout and grow. As beavers cut trees, branches then grow from the remaining stumps, providing beavers with fresh food.

The beaver is a keystone species, increasing biodiversity in its territory through creation of beaver ponds and wetlands. As wetlands are formed and riparian habitats enlarged, aquatic plants colonize newly available watery habitat. Insect, invertebrate, fish, mammal, and bird diversity are also expanded.

Reproduction:

Beavers live an average of 10 to 12 years in the wild. They generally mate for life and live in family units that consist of an adult male and female and three to four kits. After mating in the winter and about 105 days of gestation, a female beaver will give birth to a litter of up to eight young, usually two to four. Once they are old enough to leave the nest, kits spend most of their time playing in the water around the lodge, but are buoyant and cannot dive. Young beavers usually stay with their parents—helping out with the family business of maintaining the lodge and dam—until they reach sexual maturity at about two years of age. Then, chased away from their natal territory by their parents, they go stake their own claim, often downstream.

Beavers - the New Government Employees?:

In the 1930s, the U.S. Government put 600 beaver to work alongside the Civilian Conservation Corps in projects to stop soil erosion by streams in Oregon, Washington, Wyoming, and Utah. At the time it was estimated that each beaver, whose initial cost was about $5, completed work worth $300.

In a pilot study in Washington state, the Lands Council is reintroducing beavers to evaluate their projections that if 10,000 miles of suitable habitat were repopulated then 650 trillion gallons of spring runoff would be held back for release in the arid fall season. This project was developed in response to a 2003 Washington Department of Ecology proposal to spend as much as ten billion dollars on construction of several dams on Columbia River tributaries to retain storm season runoff. The State of Utah published a Beaver Management Plan which includes re-establishing beavers in ten streams per year for the purpose of watershed restoration each year from 2010 through 2020.

Conservation Status:

In the 18th and 19th centuries, beavers were killed intensively for their fur, which was used as currency for a time. Some historians credit beavers—the exploitation of their fur, in particular—with contributing more to development of the United States and Canada than any other animal.