RECENT APPROACHES TO CONTROLLING MOUNTAIN BEAVERS (Aplodontia rufa) IN PACIFIC NORTHWEST FORESTS

Authors

Dan L. Campbell, USDA, Animal and Plant Health Inspection Service, Forest Animal Damage Control Research Station, Olympia, Washington 98502Follow
James Evans, USDA, Animal and Plant Health Inspection Service, Forest Animal Damage Control Research Station, Olympia, Washington 98502

Date of this Version

March 1988

Abstract

Biologists of the Denver Wildlife Research Center are currently investigating ways of managing mountain beaver (Aplodontia rufa) populations and are developing methods for alleviating mountain beaver damage to conifer trees being grown for timber in the Pacific Northwest. Studies initiated in 1986 indicated that aversive conditioning with Big Game Repellent Powder (BGR-P) dusted on cull Douglas-fir (Pseudotsuga menziesii) seedlings placed in burrows significantly reduced mountain beaver damage to planted seedlings treated with BGR-P and to untreated seedlings. Trials also showed that strychnine-sword fern (Polvstichum munitum) baits prepared with a 4.9% (active) strychnine paste concentrate (SLN Reg. No. ID-870003) are very effective and selective for mountain beaver control. Other subjects discussed include results of several probes with toxic baits and phosphine gas, trials with a drug and a wetting agent to induce hypothermia, destruction of underground nests to prevent reinvasion, and mountain beaver behavior associated with controlling damage.