Hobbies And Interests
The History of Oregon's Beavers
The Oregon State Legislature named the beaver Oregon's Official State Mammal in 1969 after a tumultuous history that nearly led the beaver to the brink of extinction in the state, according to the Oregon Department of Fish and Wildlife. Much of Oregon's early expansion and economy was based on the exploitation of the area's abundant beaver population. Trappers and traders pushed the limits of the frontier to satisfy the demand in Europe for beaver pelts. Current state wildlife regulations protect the beaver on public lands and regulate the actions of private landowners towards the beaver populations found within their property lines.
Beaver Families
Beavers live in family units of about 12 members. They breed in winter and produce young, which are called "kits," in the spring. A normal litter averages about four kits. They will remain with the parents for at least two years and share the den or lodge with any other offspring of the parent beavers. The entire clan maintains a den, or lodge, and gathers food in preparation for the winter months. Beaver dwellings are designed to offer shelter from attacks by predators such as cougars, bears and bobcats. They must also provide access to food stores in case of flooding or icy weather.
Habitats
Beavers live in shoreline lodges or in dens. Dens are dug into the sides of riverbanks. A lodge is constructed of branches and twigs that are cemented together with applications of mud. Both types of dwellings are accessible only through entrances that are below the water line and can be built only where there is a deep-water pool or stream. If a beaver cannot find either, it will build a dam to create the right environment for its housing. Dams are made of wood, plants, stones and any other materials at hand. The Department of Fish and Wildlife reports that a dam can be made as high as 10 feet and as wide as 165 feet.
Impact on the Ecosystem
Beavers have been credited with providing the environmental conditions that are allowing the endangered coho salmon to make a comeback, according to Bonnie Henderson. Her article in Oregon Quarterly details the positive effects of beaver construction upon salmon habitats. The pools their dams create are safe havens for young fish. Streams and ponds that have been altered by beaver engineering enable fish to more easily return to their spawning grounds. The debris left by beavers in pools where they build their dens also provide the start for burgeoning ecosystems as insects breed in the debris, and birds and fish in turn feed on the insects.