Beavers -- Wildlife in Our Backyards
By Marjorie Pless Natural Resource Protection
Beavers have been viewed by many Native Americans as the “sacred center” of the earth because they change the land-scape and create rich wetland habitat for other mammals, fish, amphibians, birds and waterfowl. About 50 percent of all wildlife species in North America are dependent upon wetlands for survival.
In the urbanized Fairfax County of today, how-ever, the growing beaver population has earned a mixed review. A number of residents, frustrated with tree damage and property flooding, would prefer that the beaver not live here. These landscape alterations create conflicts that the Park Authority must attempt to resolve.
Beavers are now considered a “keystone species” because, through dam building, they help to control flooding and erosion and improve water quality. In stream valleys that have no resident beaver popula-tions, scientists have found that stream waters move more rapidly, cut deeper channels, erode more land, lower the water table, and function more like drainage ditches than stream ecosystems. Several localities have brought in beaver to help in stream restoration; the effort has sometimes proved to be successful where handmade structures have failed.
Beavers are the largest rodents in North America, weighing as much as 80 pounds and reaching four feet in length, including their long, flat tails. Their famous two long curving incisors are coated with an orange-hued protective covering. These powerful teeth enable the beaver to cut through a six-inch tree trunk in just 15 minutes! Beavers must constantly cut wood; if they didn’t their front teeth, which grow very rapidly, would curl back into their skulls. Their canoe-paddle- like tails are used for maneuvering under water, for balancing on land when cutting trees and for slap-ping the water’s surface as a danger warning.
At two to three years of age, a beaver leaves its family, often with strong encouragement from its growing multi-generational relatives. The beaver travels nearby streams in search of a place to make its own home. The beaver will first select an area, build a dam to slow the flow of water and raise water levels before determining where to build its lodge with its underwater entrance. In Fairfax County, beavers often burrow into stream banks and create dens instead of lodges because of the degraded condition of the streams.
Beavers forage close to home for their favorite trees like cottonwood, willow, alders, red maples, poplars, dogwoods and birches. The trees generally resprout with bushy growth after the beaver’s pruning efforts. Beavers’ winter diet consists of the bark of these trees, which they gnaw from cut sticks similar to the way humans gnaw on ears of corn. During the remainder of the year, they eat aquatic vegetation such as cattail tubers, sedges and grasses.
The Fairfax County Park Authority considers beaver to be a natural and beneficial part of the environment. The agency strives to give citizens an understanding of and appreciation for beaver and to promote peace-ful coexistence. Conflicts arise when beaver activity interferes with water flow and when tree damage is observed.
There are a number of steps that citizens can take to reduce beaver damage to their property. The Park Authority has a Wildlife Conflict Resolution policy to address such issues and relies upon cooperation with proper ty owners to resolve problems in a responsible manner. For further information or for a copy of the Park Authority brochure on beavers, please call the Authority’s Resource Management Division at 703- 324-8674.