Bats Swarm Where They Hibernate: Compositional Similarity between Autumn Swarming and Winter Hibernation Assemblages at Five Underground Sites

Abstract

During autumn in the temperate zone of both the new and old world, bats of many species assemble at underground sites in a behaviour known as swarming. Autumn swarming behaviour is thought to primarily serve as a promiscuous mating system, but may also be related to the localization and assessment of hibernacula. Bats subsequently make use of the same underground sites during winter hibernation, however it is currently unknown if the assemblages that make use of a site are comparable across swarming and hibernation seasons. Our purpose was to characterize the bat assemblages found at five underground sites during both the swarming and the hibernation season and compare the assemblages found during the two seasons both across sites and within species. We found that the relative abundance of individual species per site, as well as the relative proportion of a species that makes use of each site, were both significantly correlated between the swarming and hibernation seasons. These results suggest that swarming may indeed play a role in the localization of suitable hibernation sites. Additionally, these findings have important conservation implications, as this correlation can be used to improve monitoring of underground sites and predict the importance of certain sites for rare and cryptic bat species.

Activity Patterns of Cave-Dwelling Bat Species during Pre-Hibernation Swarming and Post-Hibernation Emergence in the Central Appalachians

“…Furthermore, the exact biological triggers for immergence into hibernation are not fully understood for bats, and these triggers may be more closely linked to fat reserves than to ambient conditions and/or prey availability [6]. Although cave-dwelling bats, and specifically MYSO, usually hibernate where they swarm [3,60], pre-hibernation long-distance movements between hibernacula/swarming sites are not uncommon [48,61]. Ambient temperatures could certainly affect the movement patterns of bats between hibernacula/swarming sites, and thus may affect mating dynamics and immergence phenology.…”

“…Prior to hibernation, many temperate cave-dwelling bat species "swarm" around hibernacula to mate and choose suitable hibernation sites [1][2][3]. This time is vital for weight gain and fat deposition, a necessity to survive the energetic demands of hibernation [4][5][6][7] which have been exacerbated by the impacts of White-nose Syndrome (WNS) impacts [8,9].…”

“…This time is vital for weight gain and fat deposition, a necessity to survive the energetic demands of hibernation [4][5][6][7] which have been exacerbated by the impacts of White-nose Syndrome (WNS) impacts [8,9]. During the late summer and early autumn, hundreds to thousands of individual bats may engage in swarming behavior outside a hibernaculum [3,10], with males being most active throughout the night and for a longer period into the autumn at or near hibernacula compared to females [11][12][13]. Still, prior to entering hibernation in mid-to late-autumn, bats continue to roost on the landscape, in trees, snags, emergent rocks, and human structures [12,14].…”

Novel Alphacoronaviruses and Paramyxoviruses Cocirculate with Type 1 and Severe Acute Respiratory System (SARS)-Related Betacoronaviruses in Synanthropic Bats of Luxembourg

“…Since migratory distances of 35 to 126 km between summer and winter roosts have been reported (51,52), and since all Luxembourgish colonies are within 45 km of each other (Fig. 1A), bats from different colonies may assemble during the autumn swarming of the males (32,53). Thus, male bats may play a particular role in virus transmission, which warrants further investigation.…”

Fecal Bacterial Communities in Insectivorous Bats from the Netherlands and Their Role as a Possible Vector for Foodborne Diseases

“…Bat droppings of 37 bats (Appendix) were collected in limestone mines, in close vicinity to villages, in the Southern part (province of Limburg) of the Netherlands during the autumn of 2008. Bat captures were carried out under Flora and Fauna Act license FF/75A/2003/150 and with permission of all site owners (Staatsbosbeheer; Limburgs Landschap) during a study after swarming behaviour (van Schaik et al, 2015). All procedures were in compliance with Dutch legislation on animal handling and welfare and wildlife conservation.…”