Black bear damage to commercial, coniferous trees on intensively managed public and private forest lands of the Pacific Northwest continues to be a problem for forest managers. Historically, methods such as relocation or spring hunts have been used in an effort to reduce bear density and damage. More recently, supplemental feeding has been used in an attempt to provide for the nutritional needs of bears during the damage period. Alternative silvicultural practices and repellents are being investigated for their ability to reduce the likelihood of bear damage. These and other methods need to be examined for their effectiveness, especially in light of social attitudes, increasing costs, and legal constraints. As part of an integrated pest management (IPM) approach, there is a need to better define the nature, timing, and extent of tree damage by bears. We review the literature and discuss the results from several studies that help answer some of these questions. Managers and researchers will be continuously challenged to find innovative and publicly acceptable methods to maintain a harmonious and delicate balance between the needs and desires of humans and the needs and propensities of black bears.

Valley pocket gophers (Thomomys bottae) cause considerable damage each year to a variety of crops. In the fall of 1997, efficacy data were collected after the hand placement of anticoagulant grain baits into underground burrows of Valley pocket gophers in northern California. Twenty-four Treatment Units (TUs) were divided into one of four treatment groups: 1) 0.01% diphacinone; 2) 0.005% diphacinone; 3) 0.01% chlorophacinone; and 4) 0.005% chlorophacinone grain baits. Each treatment group contained five treated TUs and one control TU. Active burrow systems were hand baited with the respective baits. Efficacy was determined through use of the open-hole index and radio telemetry. Neither the 0.005% or 0.01% chlorophacinone or diphacinone grain baits met the Environmental Protection Agency’s 70% standard for verifying efficacy of rodenticides. Potential reasons for the low efficacy of less than 10% for the four treatment groups are discussed.