Abstract
Fission–fusion dynamics appear common among temperate bats where females form roost groups that change in size and composition, as females switch roosts almost daily. One hypothesis for frequent roost switching is that females move to find suitable thermal conditions as ambient conditions change. Tests of this hypothesis have, however, been conducted mostly at roosts in artificial structures where microclimate is relatively stable. The goal of our study was to determine whether roost switching and roost use by northern long-eared bats, Myotis septentrionalis, that roost in trees are related to ambient conditions. We used generalized linear fixed effects models to explore the influence of roost characteristics and changes in ambient conditions on the likelihood of roost switching. We used canonical correlation analyses to examine the relationship between ambient conditions and roost characteristics. Roost switching was indeed linked to ambient conditions together with characteristics of roosts on the previous day; the best descriptors of roost switching differed between the two geographical regions we analysed. In Nova Scotia, females were less likely to switch roosts when it rained, particularly if they were in roosts below surrounding canopy whereas they were more likely to switch roosts when they were in roosts of high decay. Females roosted in shorter trees in earlier decay classes on warm days, as well as on windy and rainy days. In Kentucky, females were more likely to switch roosts at high temperatures, particularly when they were in roosts in high decay. Females roosted in shorter, decayed trees on warm days, and in less decayed trees with small diameter on windy and rainy days. Our results suggest bats switch roosts in response to changes in ambient conditions to select suitable roosting conditions, which may explain some of the proximate factors shaping fission–fusion dynamics of bats.
| Original language | English |
|---|---|
| Pages (from-to) | 47-57 |
| Number of pages | 11 |
| Journal | Animal Behaviour |
| Volume | 122 |
| DOIs | |
| Publication status | Published - Dec 1 2016 |
Bibliographical note
Funding Information:We are grateful to Jessica Corkum, Luke Dodd, Jenny Dufreche, Taiadjana Fortuna, Erin Hennessey and Florent Valetti for assistance in DLPP fieldwork. We thank Jimmy Watkins, Mike Brandenberg and Charlie Logsdon for their assistance in supporting work in FKMR. Gerald Wilkinson and John Ratcliffe provided comments on an earlier version of the manuscript. The research in DLPP was supported by a Natural Sciences and Engineering Research Council of Canada (NSERC) Canada Graduate Scholarship D, Dalhousie University Faculty of Graduate Studies Scholarship and Patrick F. Lett Graduate Student Assistance Bursary to K.J.P. The research was also supported by NSERC Discovery Grants to M.L.L. and H.G.B. Funding was also provided by the Nova Scotia Species at Risk Conservation Fund and Nova Scotia Habitat Conservation Fund . Considerable in-kind support was provided by the Nova Scotia Department of Natural Resources . The research in FKMR was supported by the United States Army Environmental Quality and Installation Basic Research 6.1 program. The Kentucky Department of Fish and Wildlife Resources graciously provided field housing for this project. Use of trade, product or firm names does not imply endorsement by the United States government.
Publisher Copyright:
© 2016 The Association for the Study of Animal Behaviour
ASJC Scopus Subject Areas
- Ecology, Evolution, Behavior and Systematics
- Animal Science and Zoology