Autumn Activity of Myotis sodalis (Indiana Bat) in Bland County, Virginia

Nocturnal activity and diurnal roosts of Myotis sodalis (Indiana bat) were studied during autumn swarming in 2000 near a hibernaculum in Bland County, VA. Bats were active in 9 habitats, using open deciduous forests more fequently, and developed lands, closed deciduous habitats, and mixed deciduous-evergreen habitats less frequently than would be expected based on random use of available habitats. Agricultural lands, intermediate deciduous forests, old field, and water were used in proportion to availability. Wooded pastures (agricultural) and recently logged areas (open woodland) provided foraging habitat. Many bats used multiple diurnal roosts; twenty-six roosts were found in 9 species of trees. Five bats, males and females, used the same roost tree for 2-3 consecutive days. Many roosts were near canopy open- ings; ten were in selective cut, clear-cut, and pastured woodlands with scattered trees and open canopies, and 5 were near or along logging roads or powerline corridors with open canopies. Eleven roosts were in forests with moderate to high canopy closure. Roosts were clumped near the cave (mean = 0.8 km; SD = 0.3). Roosts closer to the cave,, although limited in number, may provide an advantage during swarming. Prolonged wet, cold weather systems appear to be a part of the seasonal cycle that drives timing of autumn swarming.