RED-BACKED VOLE (CLETHRIONOMYS GAPPERI) RESPONSE TO DISTURBANCE IN SUBALPINE FORESTS: USE OF REGENERATING PATCHES

We investigated scale-dependent habitat selection by the southern red-backed vole (Clethrionomys gapperi) in subalpine forests and 20- to 30-year-old regenerating timber harvests of the central Rocky Mountains. At the macrohabitat level, C. gapperi preferred forest stands, which had more overstory canopy cover, more uniformly distributed coarse woody debris (CWD), and more dwarf huckleberry (Vaccinium scoparium) than regenerating harvested stands. Further, C. gapperi was captured in forest stands up to harvest boundaries but crossed them significantly less than expected by chance. Analysis of microhabitat selection indicated that, in forest stands, C. gapperi showed selection at a fine spatial scale, strongly favoring CWD microhabitats and avoiding those dominated by V. scoparium. Our results suggest that older, regenerating clear-cuts in the Rocky Mountains can have clearly defined impacts on C. gapperi similar to those immediately after timber harvests, but that regenerating clear-cuts do support some use by C. gapperi. The results support the association of C. gapperi with CWD and forest overstory in western montane habitats and indicate a noticeable response to forest boundaries but no direct edge effect.