Beaver
Last Review/Updated: May 31, 2002
Castor canadensis
The beaver, Canada's national emblem, is the largest North American rodent. Adults weigh about 20 kg (44 lb), but may get as large as 35 kg (77 lb). The beaver is remarkably adapted to its aquatic and logging life style. Its flat, scaly tail serves as a rudder when the beaver is swimming, as a prop when standing, as a lever when dragging logs, and as a warning device when slapped on the water. (The belief that the tail is used as a trowel for mud is a myth). The digits (fingers) and claws of the forepaws are long and delicate to aid in the handling of wood. Those of the hind foot are broad with webbing of skin between the toes to propel the animal through the water.
The rich, deep fur of the beaver has been prized by furriers for centuries. The long and dense undercoat provides excellent insulation; and the long guard hairs that grow through the underfur form a rich reddish-brown outer coat.
Beaver ponds are usually occupied by one family of beavers. The average colony contains one pair of adults, about four young of the year (kits), and young from the previous year (yearlings). Mating takes place in January and February, with young being born from April through June. Young do not assist in the work of the colony until their second summer. They become adults in their second winter, and are driven from the colony to start a dam and a colony of their own.
Beavers eat the bark of poplar, willows, cottonwood, and other trees and shrubs. In summer, they also eat pond weeds, water-lillies, and cattails. Beavers occur in all life zones except the alpine.
