American Beaver

American Beaver.jpg


Scientific Name:Castor canadensis
Habitat:Ponds, lakes, or slow moving streams bordered by stands of small trees.
Adult Weight:30 - 70 lbs.; 35 - 40 lbs. average
Adult Body Length:25 - 30 inches with 9 - 10 inch tail
Breeding Period:January - February
Litters Per Year:1
Litter Size:1 - 8, average 4
Life Expectancy:9 - 11 years
Foods:Bark and twigs from trees such as aspen, poplar, maple, and cottonwood. Also aquatic and marsh plants


Besides man, the beaver is one of the few animals that can change their environment to benefit themselves. They are master dam builders, pooling deep water behind dams that are typically four or five feet high. Occasionally dams exceed three hundred feet long, and one record dam in Montana was 2,140 feet long. Beaver carry branches in their teeth or wedged between their front legs and chest. They also carry mud between their front feet and chest. The branches and mud are wedged into any area where water flows until a solid dam is completed.



The beaver found in Ohio today is not the first of its kind to live in the state. A relation, the Giant Beaver, Castoroides ohioensis, roamed the land during the Ice Age. They reached lengths up to seven and a half feet, the size of a medium black bear! Giant Beaver have been found mostly in the Till Plains of Ohio, which stretch from the state's western boundary eastward to Columbus. They became extinct about 10,000 years ago.


The beaver existed in ponds, streams and rivers throughout, not only Ohio, but also most of North America. Prehistoric Native Americans used them for fur and food. Images of beaver have been found in the artwork of Hopewell platform pipes.

Historic Native Americans also hunted them for the meat in their large, flat tails and for their pelts. They began to trade pelts to Europeans they encountered. The European explorers of North America wanted fur more than any other resource. Including timber, gold, or land. From the 1600s to the 1800s, the beautifully thick, water repellent beaver pelt was prized in Europe and America, especially in the making of tall, beaver felt hats. Also, their strong musk glands produce castoreum, used in making perfumes. Companies, like Canada's Hudson's Bay Company and towns, like Chicago, were formed because of the fur trade industry. For a long time, beaver pelts were used as money. The cost of a rifle was a pile of beaver skins the same height as the gun. In 1670, Hudson's Bay Company records stated that a beaver pelt would buy a pound of tobacco, a one-pound kettle, four pounds of shot, or two hatchets.

The Iroquois living in the New York area led the fur trade. They fought other Native American tribes for prime beaver territory. When the beaver population declined in this area by the middle of the 17th century, the Iroquois moved westward into the Ohio country. The intense competition for control of the fur trade between tribes and the French and English was a major cause of the Beaver Wars.


The heaviest trapping occurred in Ohio between 1750 and 1800. In the 1770s, David Zeisberger, a Moravian Missionary remarked, "The beaver was formerly found in great numbers in this region, but since the Indians have learned from the whites to catch them in stell-trap [sic], they are more rarely found." Because of intense trapping, beaver populations drastically fell by the end of the 18th century.

Nineteenth Century

Between 1853 and 1877, the Hudson's Bay Company, alone, shipped 3 million pelts to Europe. The invention of felt machines turned fashions away from the use of beaver.

By 1830, the beaver was extirpated from Ohio.

Before Europeans arrived, there was an estimated 400 million beavers. By 1890, there were only isolated pockets in the Midwest.

Twentieth Century

It was over 100 years before evidence of beaver in Ohio was seen again. The first was in Ashtabula County in 1936. After a beaver dam caused flooding in 1946 in Columbiana County, a study revealed that there were approximately 100 beaver in eleven Ohio counties. By the early 1970s, populations had increased to over 5,000 beaver in thirty-seven counties. Just a few years later, an estimated 7,500 beaver could be found in forty Ohio counties, especially in eastern and southeastern areas of the state. Since 1961 there has been limited beaver trapping allowed in Ohio.

In 1984, there were roughly 2 million beaver in the United States.

The 1997-98 Beaver Helicopter Survey by the Ohio Department of Natural Resources reported the recovered beaver population in Ohio to be 25,000, an increase of 35% from the previous year.

See Also