North American beaver
| American Beaver Template:StatusConcern | ||||||||||||||
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| Castor canadensis |
The American Beaver (Castor canadensis) is a large semi-aquatic rodent native to North America. Its fur is dark brown. It has a rounded head, a large flat paddle-shaped tail and webbed hind feet.
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. An scent gland near their genitals secretes an oily substance known as castoreum which is used to waterproof its fur. A thick layer of fat under its skin insulates the beaver from its cold water environment.
They sometimes make their home in a river bank, but they are best known for building dams across streams and constructing their "lodge" in the artificial pond which forms. The entrance to the lodge or burrow is located underwater.
Research has shown that dam-building behaviour and choice of dam location is triggered by the sound of flowing water.
The dam is constructed using sections of deciduous trees, especially birch, aspen, willow and poplar. This vegetation is also an important part of the beaver's diet. The trees are cut down using their strong incisor teeth.
These animals are considered pests in some areas areas because their dams can cause flooding in nearby areas. They are incredibly persistent in repairing any damage to the dam and the only way to convince them to stop is to remove them from the location.
During the summer, beavers also eat other aquatic plants.
Besides providing a safe home for the beaver, beaver ponds also provide habitat for waterfowl and other aquatic animals.
Beavers usually mate for life. The young beaver "kits" typically remain with their parents for up to two years.
These animals are often trapped for their fur. During the early 19th century, trapping eliminated this animal from most of its range. The beaver furs were used to make clothing and top-hats. Much of the early exploration of North America was driven by the quest for this animal's fur.
Other predators include the Coyote, the Grey Wolf, the Bobcat and the Red Fox.
This is the national animal of Canada; it is depicted on the Canadian five-cent piece and was on the first Canadian postage stamp, the Three Penny Beaver. It is also the state animal of Oregon, and a common school emblem for engineering schools, including the California Institute of Technology and the Massachusetts Institute of Technology.
External links
- Canadian Heritage - the beaver as a national symbol
- The romance of the beaver; being the history of the beaver in the western hemisphere, by A. Radclyffe Dugmore. Illustrated with photographs from life and drawings by the author. Publisher: Philadelphia, J.B. Lippincott company; London, W. Heinemann 1914 (a searchable facsimile at the University of Georgia Libraries)