Journal of Comparative Physiology B

, Volume 179, Issue 4, pp 433–441 | Cite as

Hibernation by a free-ranging subtropical bat (Nyctophilus bifax)

  • Clare StawskiEmail author
  • Christopher Turbill
  • Fritz Geiser
Original Paper


Knowledge about torpor in free-ranging subtropical bats is scarce and it is widely believed that low and stable ambient temperatures are necessary for prolonged torpor. We present temperature-telemetry data from free-ranging male (n = 4) and female (n = 4) subtropical vespertilionid bats, Nyctophilus bifax (~10 g), exposed to pronounced daily fluctuations of ambient temperature. All bats used torpor on every day in winter and both males and females exhibited multi-day torpor bouts of up to 5.4 days. Although females were larger than males, patterns of torpor were similar in both sexes. Torpor use was correlated with prevailing weather conditions and, on days when bats remained torpid, maximum ambient temperature was significantly lower than on days when bats aroused. Moreover, the duration of interbout normothermic periods at night increased with increasing average nightly ambient temperature. Skin temperature of torpid bats varied by 10.2 ± 3.6°C day−1 (n = 8, N = 47) and daily minimum skin temperature was positively correlated with the daily minimum ambient temperature. Our study shows that prolonged torpor is an important component of the winter ecology of a subtropical bat and that torpor and activity patterns of N. bifax predominantly reflect prevailing weather conditions.


Arousal Austral winter Insectivorous Multi-day torpor Temperature 



Body temperature


Metabolic rate


Ambient temperature


Skin temperature



We thank Anaïs Le Bot for help with fieldwork and many great ideas and discussions. For their help in the field and advice we thank Margaret and Mike Stawski, Mark and Anne Brigham and Aaron Trachtenberg. Brad Law provided logistical advice and Gerhard Körtner, Lisa Warnecke and Jamie Turner for helpful discussions. Permits for this study were issued by New South Wales National Parks and Wildlife Service and the Animal Ethics Committee of the University of New England. The work was supported by grants from University of New England and Bat Conservation International to CS and the Australian Research Council to FG.


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Clare Stawski
    • 1
    Email author
  • Christopher Turbill
    • 1
    • 2
  • Fritz Geiser
    • 1
  1. 1.Department of Zoology, Centre for Behavioural and Physiological EcologyUniversity of New EnglandArmidaleAustralia
  2. 2.Research Institute of Wildlife EcologyUniversity of Veterinary Medicine ViennaViennaAustria

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