Dens of northern flying squirrels in the Pacific Northwest

• Published in: The Journal of wildlife management 1997-07, Vol.61 (3), p.684-699
• Main Authors: Carey, A.B. (Pacific Northwest Research Station, U.S. Forest Service, Olympia, WA.), Wilson, T.M, Maguire, C.C, Biswell, B.L
• Format: Article
• Language: English
• Subjects: Aerial locomotion; AMENAGEMENT FORESTIER; Animal behavior; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Bird nesting; BOSQUE VIRGEN; Coastal ranges; Conifers; Conservation, protection and management of environment and wildlife; Deciduous trees; Dens; FAUNE ET FLORE SAUVAGES; FOREST MANAGEMENT; FORET VIERGE; Fundamental and applied biological sciences. Psychology; GESTION; GLAUCOMYS; HABITAT; HABITATS; MANAGEMENT; Old growth forests; old-growth forest; ORDENACION FORESTAL; OREGON; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; RODENTIA; Rodents; Squirrels; Tree cavities; TREE HOLES; Tree stumps; Trees; VIDA SILVESTRE; VIRGIN FORESTS; WILDLIFE; Wildlife management
• ISSN: 0022-541X; 1937-2817
• DOI: 10.2307/3802176

Silvicultural prescriptions to enhance northern flying squirrel (Glaucomys sabrinus) habitat have been suggested as an aid for recovery of the threatened northern spotted owl (Strix occidentalis caurina). Flying squirrels are hypothesized to be limited by den sites (cavities in trees) and by food (truffles). However, no quantitative information exists on den sites of flying squirrels. Therefore, during 1986-94, we used radio-telemetry to locate 604 different den sites in the southern Coast Range of Oregon, the southern Olympic Peninsula, and the Puget Trough of Washington. Den sites included cavities in live and dead old-growth trees; cavities, stick nests, and moss nests in small (10-50 cm dbh) second-growth trees; dens in cavities in branches of fallen trees; and dens in decayed stumps of old-growth trees and suppressed young trees. Two-thirds of all dens located were in live trees. Most dens were located during a study of second-growth forests in the Puget Trough. Females selected cavities for maternal dens. Squirrels used multiple dens; denning partners varied with den. Dens of males were 211 ± 7 m apart; dens of females were 108 ± 4 m apart. Males used 2.2 ± 0.1 dens per month; females 2.3 ± 0.1 dens per month. Dens, except maternal dens, were often occupied simultaneously by several adult squirrels. Many fragile den sites were used by females. Secure cavities are scarce and may limit reproductive success. Management for cavity trees and dens could prove fruitful in owl recovery and habitat restoration efforts.