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Response of northern flying squirrels to supplementary dens.

Informally Refereed

Abstract

The northern flying squirrel (Glaucomys sabrinus) is a keystone species in Pacific Northwest conifer forests, consuming and disseminating spores of ectomycorrhizal fungi essential to Pinaceae and preyed upon by different vertebrate predators. Increasing the numbers of flying squirrels has been suggested as part of a strategy to increase the population viability of the spotted owl (Strix occidentalis). Flying squirrel populations in second-growth forests have been hypothesized to be limited by 1) abundance of den sites, 2) quality, quantity, and diversity of food, and 3) predation. I conducted an experiment to test the {} hypothesis that number and quality of dens did not affect flying squirrel population density. in 1992, I added nest boxes and tree cavities to 8 of 16 Douglas-fir (Pseudotsuga menziesii) stands of various management histories in the Puget Trough of Washington. Flying squirrel use of boxes increased over 5 years, predominantly by pregnant and nursing females. Proportions of adult females breeding, however, did not increase. Population sizes did not increase significantly. Dens were not the overriding factor limiting flying squirrels in second-growth Douglas-fir forest in the Puget Trough of Washington. Rather, a complex of factors seemed to be operating, and limiting management focus to one or 2 factors may not produce desirable results.

Keywords

Cavities, dens, forest management, Glaucomys sabrinus, limiting factors, nest boxes, northern flying squirrels, predation, wildlife management

Citation

Carey, A.B. 2002. Response of northern flying squirrels to supplementary dens. Wildlife Society Bulletin. 30(2): 547-556
https://www.fs.usda.gov/research/treesearch/6108