Autumn Swarming of the Pond Bat Myotis Dasycneme at Hibernation Sites in Latvia/Tiigilendlase Myotis Dasycneme Sugisene Parvlemine Talvituspaikade Juures Latis

Abstract

Capturing of swarming bats was carried out at five hibernation sites in Latvia in 2005- 2007. In total 436 pond bats Myotis dasycneme were caught and marked with forearm rings. The most prominent swarming was observed in August-September, which corresponds with relevant results from other countries. Most bats caught were adults, with the domination of adult males. Spearman's rank correlation showed statistically significant changes in numbers of different age and sex groups of bats during the swarming season. Behavioural observations of bats and recaptures of males indicate that possibly the main reason for the swarming activity of pond bats is mating.