Mountain Pine Beetle Presence Affects Nest Patch Choice of Red-Breasted Nuthatches

Abstract: The mountain pine beetle (Dendroctonus ponderosae) outbreak in western Canada poses significant conservation concern; thus, insights into its effects on wildlife habitat are essential. We used generalized linear mixed models to examine the influence of quaking aspen (Populus tremuloides) and mountain pine beetle—infected lodgepole pine (Pinus contortus) on nest patch selection of red-breasted nuthatches (Sitta canadensis) in central British Columbia, Canada. Prior to the outbreak, nuthatches selected nest patches with 64% more suitable nest trees (standing dead aspen, ≥12.5 cm dbh) than available (103 trees/ha vs. 63 trees/ha, respectively), but in outbreak years nuthatches chose nest patches with 37% more beetle-infected pine trees than available (63 trees/ha vs. 46 trees/ha, respectively). Our results suggest that nuthatches select sites that maximize nesting and foraging opportunities and, during food pulses, may trade off higher densities of suitable nest trees for higher densities of foraging trees. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):733–737; 2008)