Survey of the patterns of nest box use among squirrels (Sciuridae) in managed forest stands in Clinton County, New York

Artificial habitat enhancements are important forest structural components that can increase the survival of squirrels (Sciuridae) and thus warrant study. Investigations of squirrel nest box usage can provide useful demographic and community information such as occupancy rates, litter size, habitat preference, species richness and abundance estimates. This artificial nest box study investigated the nesting patterns of squirrels from late winter through early fall 2011 in managed forest stands in Clinton County, New York. Squirrels are sensitive to forest disturbance, hence we compared sites of varying silvicultural activity (e.g., managed for production of timber or maple syrup versus an undisturbed reference stand). A total of 48 nest boxes were constructed and monitored across three separate sites (e.g., reference, logged, and sugaring). Prior research suggested that occupancy may be a function of nest box height (~3.5m and ~5m) and site-specific tree cavity/snags/drey abundance, thus height preference and alternative nesting options were monitored in the survey and analyzed to report detection probability and occupancy estimates in Program Presence. Visual confirmation of northern flying squirrels (Glaucomys sabrinus Shaw) was made in 81%, 44%, and 13% of the nest boxes in the reference, logged, and sugar site, respectively. Approximately 79% of the nest boxes showed evidence of wildlife visitation (e.g., scat, crushed seeds, or nesting material). Additionally, 87% of the high boxes (5m) versus 71% of the low boxes (3.5m) were utilized, and 17% of all occupancies contained multiple individuals. This survey provides additional multi-season occupancy data for an elusive mammal species under managed habitat regimes. We recommend that management plans include a wildlife habitat component that maintains snag trees and live cavity-trees in forest stands. When appropriate, stand management plans could also include installing habitat enhancement structures such as artificial nest boxes for squirrels.