Comparison of Beaver Dam Densities Between Drainages Open and Closed to Trapping (Poster)

Abstract

Montana Fish, Wildlife and Parks has implemented beaver trapping closures in 19 drainages within 11 counties throughout the state. Since beaver trapping closures were implemented, there has not been an analysis of beaver activity in these drainages, nor has there been a comparison to drainages with similar characteristics that remained open to trapping. Using the Beaver Restoration and Assessment Tool (BRAT), we identified drainages that were comparable in the amount of suitable beaver habitat but have remained open to trapping. We included information on public versus private land ownership and level of accessibility to these drainages, variables that may affect beaver dam counts and trapping pressure. We used Google Earth to conduct beaver dam counts as a measure of beaver occupancy and influence. Initial results from 12 pairs of drainages show a majority of drainages that have been closed to trapping have more beaver dams per kilometer of suitable habitat than paired drainages that have remained open to trapping, though this trend is inconsistent across the study area. Although the scope of this study does not account for other confounding factors such as disease and land use, our preliminary results suggest trapping closures may influence the impact of beavers in stream drainages in Montana. Our results can help inform biologists on where further study is needed and what actions could be taken to influence beaver populations. Our future plans are to find multiple open drainages for each closure for a more robust study.