North American Beaver - Ecology

Ecology

The beaver was trapped out and almost extirpated in North America as its fur and castoreum were highly sought after. The beaver furs were used to make clothing and beaver hats. In the United States extensive trapping began in the early 17th century with more than 10,000 beaver per year taken for the fur trade in Connecticut and Massachusetts between 1620 and 1630. From 1630 to 1640, approximately 80,000 beaver were taken annually from the Hudson River and western New York. As eastern beaver populations were depleted, French and American trappers pushed west. In fact, much of the westward expansion and exploration of North America was driven by the quest for this animal's fur. Before the 1849 California Gold Rush, there was an earlier 19th century California Fur Rush which drove the earliest American settlement in that State. During the approximately 30 years (1806–1838) of the era of the Mountain Man, the West from Missouri to California and from Canada to Mexico was thoroughly explored and the beaver was brought to the brink of extinction.

With protection in the late 19th and early 20th centuries the current beaver population has rebounded to an estimated 10 to 15 million; however this is still a fraction of the originally estimated 100 to 200 million North American beaver before the days of the fur trade.

These animals are considered pests in some parts of their range because their dams can cause flooding in nearby areas, or because their habit of cutting down trees can pose danger to people, as for instance, in Charlotte, North Carolina's Park Road Park. Because they are persistent in repairing any damage to the dam, they were historically relocated or exterminated. However, non-lethal methods of containing beaver-related flooding have been developed. One such flow device has been utilized by both the Canadian and U.S. governments, called "Beaver Deceivers," or levelers, invented and pioneered by wildlife biologist, Skip Lisle.

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.