We radio-tracked 4 solitary subadult (2 male and 2 females) and 3 adult female evening bats (Nycticeius humeralis) to 7 and 14 roost trees, respectively, during the summer of 1997 on the Upper Coastal Plain of South Carolina. Roosts for both age-classes were located in cavities and under exfoliating bark in live trees and dead snags. Based on nightly exit counts, adult female evening bats roosted communally. Some roosts were presumed to be active maternity colonies. Five of six subadult roosts and one adult female roost were located under exfoliating bark on dead snags in beaver (Castor canadensis) ponds. Thirteen of 14 adult female evening bat roosts were located in cavities in live longleaf pines (Pinus palustris) in stands of relatively mature, park-like, pine plantations. One subadult roost was located under exfoliating bark in a live longleaf pine. No evening bats roosted in the more densely canopied, nearby bottomland hardwood stands, mixed pine-hardwood stands or loblolly pine (P. taeda) stands. Roost fidelity by individual evening bats was short (2.3 roost-days per bat) and did not differ between subadults and adult females. Although average daily maximum roost temperature was higher in subadult roosts than in adult female roosts, internal average temperature, daily minimum temperature and daily temperature range did not differ significantly between the two roost categories. Overstory height surrounding roost trees, canopy density and basal area of pine in the surrounding stand were greater at roosts within longleaf pine stands than those in beaver ponds. Conversely, stand basal area, overstory tree species richness, abundance of Spanish moss (Tillandsia usneoides) and basal area of hardwood trees were greater at roost sites within beaver ponds than those same measures in longleaf pine stands.
ACCESS THE FULL ARTICLE
The American Midland Naturalist
Vol. 145 • No. 1
January 2001
Vol. 145 • No. 1
January 2001