Relationship between aspen and alder size and abundance on beaver dam occupation.

Abstract

I tested the hypothesis beavers (Castor canadensis) abandon dams due to depletion of preferred species. An abandoned and active site were each studied on the Maple River and Carp Creek. The predictions were that there would be fewer standing aspens (Populus spp.), alders (Alnus spp.), and birch (Betula spp.) at the abandoned sites, and that due to selective foraging by beavers there would be a strong size-distance relationship at the abandoned sites. While there were significantly more trees at the active sites, the expected distribution at the abandoned sites was absent. These mixed results suggest that other factors should also be considered and that a more comprehensive study would be needed to properly test the hypothesis.