PARENT SESSION
Contributed Oral Session 44: Mammal Ecology: Seals, Deer, and Bats
Tuesday, August 9, 8:00 AM - 11:30 AM, Meeting Room 518 C, Level 5, Palais des congrès de Montréal

Nest tree use by flying squirrels (Glaucomys sabrinus and G. volans) in central Ontario.

Holloway, Gillian^*,1, Malcolm, Jay¹, ¹ Faculty of Forestry, University of Toronto, Toronto, Ontario, Canada

ABSTRACT- Reductions in the supply of nesting cavities is a frequently observed consequence of logging and one that may be of particular concern for secondary cavity nesters. In this study, we examined nest use by radio-collared northern and southern flying squirrels in unlogged coniferous and hardwood forests in Algonquin Provincial Park, Ontario, and for the latter species, in logged forests as well. During the summers of 2003 and 2004, 23 southern flying squirrels, and 16 northern flying squirrels were tracked to 76 and 60 nests respectively. The majority of nests of southern flying squirrels were in live, declining trees (70%) or snags (24%), whereas northern flying squirrels used a wider variety of nest substrates (27% snags, 47% live declining trees, and 26% healthy trees). Large trees and American beech (Fagus grandifolia) were used by southern flying squirrels more often than expected based on chance, whereas birch (Betula sp.) and aspen (Populus sp.) were used by northern flying squirrels more than expected. The latter species also used nesting areas with more declining trees, snags and cavity trees than expected. Southern flying squirrels in logged sites used nesting areas with smaller trees and fewer snags and cavity trees than in unlogged sites. A few animals used one nest cavity for the majority of the summer; whereas others switched to new nests every 1-2 weeks. The average number of nests used per animal was 4.0 (range 1-6) for southern flying squirrels and 3.6 (range 2-7) for northern flying squirrels. Compared to unlogged sites, radio-collared animals in logged stands switched nests more frequently and used the same nests for shorter periods of time. The average number of occasions a southern flying squirrel was located in a given nest was higher in unlogged sites (mean = 3.6) than in logged sites (mean = 2.0). Radio-collared southern flying squirrels nested together as pairs, but only in cut stands. This study supports past research indicating that northern flying squirrels are old-growth associates. Southern flying squirrels, on the other hand, demonstrated more flexible nest use and behaviour. However, nest availability may be limiting in recently logging areas.

Key words: Glaucomys sabrinus, Glaucomys volans, forest management, nest trees