Evaluating landowner-based beaver relocation as a tool to restore salmon habitat

Relocating American beavers (Castor canadensis) from unwanted sites to desirable sites (i.e., where damage exceeds stakeholder capacity) has been posited as a method to enhance in-stream habitat for salmonids in the Pacific Northwest region of the US; however, no studies have evaluated this method. From September–December 2011, we trapped and relocated 38 nuisance beavers using guidelines available to Oregon landowners. Release sites were selected from models that identified high values of beaver dam habitat suitability and where dams would increase intrinsic potential of coho salmon (Oncorhynchus kisutch). Mean distance moved from release sites within 16 weeks post-release was 3.3 ±0.2 (SE) stream km (max 29.2 km). Mean survival rate for relocated beavers was 0.47 ±0.12 (95% CI: 0.26–0.69) for 16 weeks post-release, while the probabilities of an individual dying to predation or disease/illness during the same period were 0.26 (95% CI: 0.09–0.43) and 0.16 (95% CI: 0.01–0.30), respectively. Dam construction was limited and ephemeral due to winter high flows, providing no in-stream habitat for coho. We conclude beaver relocation options available to landowners in Oregon may not be an effective option for stream restoration in coastal forestlands due to infrequent dam occurrence and short dam longevity.