Skip to main content
U.S. flag

An official website of the United States government

Methods to predict beaver dam occurrence in Coastal Oregon

Formally Refereed

Abstract

Pools provided by beaver (Castor canadensis) contribute to critical habitat requirements of salmonids in fluvial systems of the Pacific Northwest, therefore more land managers are interested in managing watersheds that include beavers or engaging in beaver-related restoration projects. We evaluated the utility of applying an existing beaver habitat suitability model to better understand beaver dam site characteristics in coastal Oregon, identify optimum dam site locations, and guide future beaver-related restoration efforts. We used a combination of t-tests, Wilcoxon rank sum tests, and a stepwise discriminant function analysis to examine stream habitat associations with field data collected at known and predicted dam sites at reach and pool/riffle levels. We found bank-full width, valley floor width, and channel gradient performed well in predicting dam locations across the Alsea River Basin. Known dam sites had wider valley floors, shallower shoreline slopes, and fewer larger, deeper pools than predicted sites. Overall, our results suggest the beaver habitat suitability model combined with a digital elevation model can be used to guide where beaver dams may occur within the Alsea River Basin, yet they do not capture fine scale habitat associations that may lead to a settling response in beavers. For example, presence of large deep pools may be necessary for beavers to escape predation before and during dam building. Results from our study may be used to prioritize potential dam sites in other coastal basins that have similar geomorphic characteristics.

Keywords

Beaver, dam habitat, salmon, stream restoration.

Citation

Petro, Vanessa M.; Taylor, Jimmy D.; Sanchez, Dana M.; Burnett, Kelly M. 2018. Methods to predict beaver dam occurrence in Coastal Oregon. Northwest Science. 92(4): 278-289. https://doi.org/10.3955/046.092.0405.
Citations
https://www.fs.usda.gov/research/treesearch/57827