Swarming behaviour and fall roost-use of little brown (Myotis lucifugus), and northern long-eared bats (Myotis septentrionalis) in Nova Scotia, Canada

Abstract

Temperate bats exhibit a poorly understood behaviour during the fall known as swarming, which has both survival and reproductive consequences. The goal of this project was to characterize how variation in physical conditions influence the movement patterns and resources used during the swarming season of the little brown bat ( Myotis lucifugus ), and the northern long-eared bat (M. septentrionalis ) in Nova Scotia, Canada. The objectives were to: 1) investigate if the swarming behaviour of male little brown bats is influenced by individual differences in body condition and reproductive status; and 2) characterize the roosts used by both species during the season. Swarming behaviour was not influenced by body condition and reproductive status alone, although the data indicate that males of a lower body conditions do return more often, and swarm for longer durations. Roosts used during the swarming season had a predominantly southwestern orientation unlike summer roosts, but were most often found in mid-late decay stage trees of conifer-dominated forests.