Journal article
High latitude Northern bats (Eptesicus nilssonii) reveal adaptations to both high and low ambient temperatures
The Journal of Experimental Biology, Vol.226(21), pp.1-10
2023
Abstract
Insectivorous bats at northern latitudes need to cope with long periods of no food for large parts of the year. Hence, bats which are resident at northern latitudes throughout the year will need to undergo a long hibernation season and a short reproductive season where foraging time is limited by extended daylight periods. Eptesicus nilssonii is the northernmost occurring bat species worldwide and hibernates locally when ambient temperatures (Ta) limit prey availability. Therefore, we investigated the energy spent maintaining normothermy at different Tas, as well as how much bats limit energy expenditure while in torpor. We found that, despite being exposed to Ta as low as 1.1°C, bats did not increase torpid metabolic rate, thus indicating that E. nilssonii can survive and hibernate at low ambient temperatures. Furthermore, we found a lower critical temperature (Tlc) of 27.8°C, which is lower than in most other vespertilionid bats, and we found no indication of any metabolic response to Tas up to 37.1°C. Interestingly, carbon dioxide production increased with increasing Ta above the Tlc, presumably caused by a release of retained CO2 in bats that remained in torpor for longer and aroused at Ta above the Tlc. Our results indicate that E. nilssonii can thermoconform at near-freezing Ta, and hence maintain longer torpor bouts with limited energy expenditure, yet also cope with high Tawhen sun-exposed in roosts during long summer days. These physiological traits will likely enable the species to cope with ongoing and predicted climate change.
Details
- Title
- High latitude Northern bats (Eptesicus nilssonii) reveal adaptations to both high and low ambient temperatures
- Authors
- Rune Sørås (Corresponding Author) - Norwegian University of Science and TechnologyMari Aas Fjelldal (Author) - Norwegian University of Science and TechnologyClaus Bech (Author) - Norwegian University of Science and TechnologyJeroen van der Kooij (Author)Katrine Eldegard (Author) - Norwegian University of Life SciencesClare Stawski (Author) - University of the Sunshine Coast, Queensland, School of Science, Technology and Engineering
- Publication details
- The Journal of Experimental Biology, Vol.226(21), pp.1-10
- Publisher
- The Company of Biologists Ltd.
- Date published
- 2023
- DOI
- 10.1242/jeb.245260
- ISSN
- 1477-9145
- Organisation Unit
- School of Science, Technology and Engineering; University of the Sunshine Coast, Queensland
- Language
- English
- Record Identifier
- 99971193002621
- Output Type
- Journal article
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