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Beavers | Beaver Overview | Beaver Damage Assessment | Beaver Damage Management | Beaver Resources | Beaver Acknowledgments | ICWDM | Wildlife Species Information |
Beaver damage is easily identified by the distinctive cone-shaped tree stumps resulting from their gnawing, and often by the presence of their dams and lodges. The latter might not be present, however, in ponds or reservoirs, or along swift mountain streams, where they burrow into banks. Usually, when beavers are active in an area; green sticks with the bark freshly peeled off may be found.
Damage caused by beavers results from feeding behavior (tree cutting) and their efforts to control water levels (dam building). Tree cutting in certain situations results in selective elimination of preferred tree species, such as aspen and cottonwood, from the vicinity (Beier and Barrett 1987). Loss of timber and crops from flooding is of much greater importance, however, especially in the southeastern United States where beaver populations have increased dramatically as a result of a decline in trapping due to low pelt prices (Woodward 1985). Beavers often use sticks to plug road culverts or water-control structures in ponds and reservoirs. Additionally, beavers can cause extensive damage to levees and human-made dams by their burrowing.
Beavers are susceptible to infection by protozoan parasites (Giardia spp.) that can cause gastroenteritis and diarrhea in humans. Transmission to humans can be prevented by use of proper water treatment measures (Davidson and Nettles 1988).
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Summary of Damage Prevention and Control Methods
Exclusion
Fence small critical areas such as culverts, drains, or other structures. Install barriers around important trees in urban settings.
Cultural Methods and Habitat Modification
Eliminate foods, trees, and woody vegetation where feasible. Continually destroy dams and materials used to build dams. Install a Clemson beaver pond leveler, three-log drain, or other structural device to maintain a lower pond level and avoid further pond expansion.
Frightening
Shooting of individuals or dynamiting or other continued destruction of lodges, bank dens, and dams, where legal, will occasionally move young colonies out of an area.
Repellents
None are registered; however, there is some evidence that repellents may be useful.
Toxicants
None are registered.
Trapping
No. 330 Conibear® traps. Leghold traps No. 3 or larger (including coil-spring types with equivalent jaw spread and impact). Basket/suitcase type traps are primarily used for live trapping. Snares can be useful, particularly in dive sets and slides where legal.
Shooting
Rarely effective (where legal) for complete control efforts and can be dangerous to humans.
Other Methods
Other methods rarely solve a beaver damage problem and may increase risks to humans and nontarget species.
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Beavers | Beaver Overview | Beaver Damage Assessment | Beaver Damage Management | Beaver Resources | Beaver Acknowledgments | ICWDM | Wildlife Species Information |
