Roost tree selection by northern long-eared bat ( Myotis septentrionalis) maternity colonies in an industrial forest of the central Appalachian mountains

Abstract

As part of a bat ecology research effort in managed forests, we tracked seven lactating northern long-eared bats ( Myotis septentrionalis Trouessart) to 12 roost trees used by maternity colonies ranging in size from 11 to 65 individuals in the central Appalachians of West Virginia. Lactating females switched among roosts on average every 5 days. Roosts were located in nine tree species, with 11 roosts in tree cavities and 1 under exfoliating bark. Eight of the roosts were located in snags; the other four were located in cavities in living trees. Black locust ( Robinia pseudo-acacia L.) snags were selected as a roost sites more than expected based on their occurrence in the forests we surveyed. Only 3 of the 24 habitat characteristics differed between actual roost trees and randomly located cavity trees. Structurally, actual roosts tended to be closer to neighboring trees than did suitable roosts in randomly located cavity trees. Tree species was an important factor that influenced roost tree selection, with black locusts being used significantly more than expected based on their abundance across the managed forest landscape we studied. All northern long-eared bat roosts were located in or below the forest canopy which suggests that solar exposure may not be as critical for selection of roost trees by maternity colonies of this species as opposed to other species of tree-roosting bat at more northern latitudes in North America. Although many previous studies have demonstrated the importance of old-growth habitat in providing roosting habitat for tree-roosting bats, use of roosting habitat and characteristics of roost sites have been little documented within intensively managed forests. Our research indicates that in managed, Allegheny hardwood–northern hardwood forests of the central Appalachians, short-lived, early successional species such as black locust may provide suitable roosting habitat for northern long-eared bats, as well as other species of bats.