Climate-mediated energetic constraints on the distribution of hibernating mammals


To predict the consequences of human-induced global climate change, we need to understand how climate is linked to biogeography1. Energetic constraints are commonly invoked to explain animal distributions, and physiological parameters are known to vary along distributional gradients2. But the causal nature of the links between climate and animal biogeography remain largely obscure2,3. Here we develop a bioenergetic model that predicts the feasibility of mammalian hibernation under different climatic conditions. As an example, we use the well-quantified hibernation energetics of the little brown bat (Myotis lucifugus) to parameterize the model4. Our model predicts pronounced effects of ambient temperature on total winter energy requirements, and a relatively narrow combination of hibernaculum temperatures and winter lengths permitting successful hibernation. Microhabitat and northern distribution limits of M. lucifugus are consistent with model predictions, suggesting that the thermal dependence of hibernation energetics constrains the biogeography of this species. Integrating projections of climate change into our model predicts a pronounced northward range expansion of hibernating bats within the next 80 years. Bioenergetics can provide the simple link between climate and biogeography needed to predict the consequences of climate change.

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Figure 1: The effect of hibernaculum temperature on total winter energy requirements of M. lucifugus (dashed line), based on a winter length of 193 days10.
Figure 2: Comparison of observed hibernaculum temperatures of M. lucifugus with those predicted to be suitable by the model.
Figure 3: Observed and predicted M. lucifugus range distributions in northern North America.


  1. 1

    Gates, D. M. Climate Change and Its Biological Consequences 162–201 (Sinauer, Sunderland, Massachusetts, 1993)

    Google Scholar 

  2. 2

    Johnston, I. A. & Bennett, A. F. (eds) Animals and Temperature: Phenotypic and Evolutionary Adaptation (Cambridge Univ. Press, Cambridge, 1996)

  3. 3

    Chown, S. L. & Gaston, K. J. Exploring links between physiology and ecology at macro-scales: the role of respiratory metabolism in insects. Biol. Rev. 74, 87–112 (1999)

    Article  Google Scholar 

  4. 4

    Fenton, M. B. & Barclay, R. M. R. Myotis lucifugus. Mammal. Spec. 142, 1–8 (1980)

    Article  Google Scholar 

  5. 5

    Rosenzweig, M. L. Species Diversity in Space and Time 8–48 (Cambridge Univ. Press, Cambridge, 1995)

    Google Scholar 

  6. 6

    Root, T. Environmental factors associated with avian distributional boundaries. J. Biogeogr. 15, 489–505 (1988)

    Article  Google Scholar 

  7. 7

    Canterbury, G. Metabolic adaptation and climatic constraints on winter bird distribution. Ecology 83, 946–957 (2002)

    Article  Google Scholar 

  8. 8

    Weiner, J. Physiological limits to sustainable energy budgets in birds and mammals—ecological implications. Trends Ecol. Evol. 7, 384–388 (1992)

    CAS  Article  Google Scholar 

  9. 9

    Kunz, T. H., Wrazen, J. A. & Burnett, C. D. Changes in body mass and fat reserves in pre-hibernating little brown bats (Myotis lucifugus). Ecoscience 5, 8–17 (1998)

    Article  Google Scholar 

  10. 10

    Fenton, M. B. Population studies of Myotis lucifugus. (Chiroptera: Vespertilionidae) in Ontario. Life Sci. Contr., R. Ont. Mus. 77, 1–34 (1970)

    Google Scholar 

  11. 11

    Webb, P. I., Racey, P. & Speakman, J. R. How hot is a hibernaculum? A review of the temperatures at which bats hibernate. Can. J. Zool. 74, 761–765 (1996)

    Article  Google Scholar 

  12. 12

    Johns, T. C. et al. The second Hadley Centre couple ocean–atmosphere GCM: model description, spinup and validation. Clim. Dyn. 13, 103–134 (1997)

    Article  Google Scholar 

  13. 13

    Rainey, R. C. in Insect Flight (ed. Rainey, R. C.) 75–112 (Blackwell Scientific, Oxford, 1976)

    Google Scholar 

  14. 14

    Schowalter, D. B. Swarming, reproduction, and early hibernation patterns of Myotis lucifugus and M. volans in Alberta, Canada. J. Mammal. 61, 347–350 (1980)

    Article  Google Scholar 

  15. 15

    Whitaker, J. O. & Rissler, L. J. Winter activity of bats at a mine entrance in Vermillion County, Indiana. Am. Midl. Nat. 127, 52–59 (1992)

    Article  Google Scholar 

  16. 16

    Raesley, R. L. & Gates, J. E. Winter habitat selection by north temperate cave bats. Am. Midl. Nat. 118, 15–31 (1986)

    Article  Google Scholar 

  17. 17

    Dwyer, P. D. Temperature regulation and cave-dwelling in bats: an evolutionary perspective. Mammalia 35, 424–455 (1971)

    Article  Google Scholar 

  18. 18

    Bell, G. P., Bartholomew, G. A. & Nagy, K. A. The roles of energetics, water economy, foraging behaviour, and geothermal refugia in the distribution of the bat, Macrotus californicus. J. Comp. Physiol. B 156, 441–450 (1986)

    Article  Google Scholar 

  19. 19

    Parker, D. I., Lawhead, B. E. & Cook, J. A. Distributional limits of bats in Alaska. Arctic 50, 256–265 (1997)

    Article  Google Scholar 

  20. 20

    Twente, J. W. Environmental problems involving the hibernation of bats in Utah. Proc. Utah Acad. Sci. Arts Lett. 37, 67–71 (1960)

    Google Scholar 

  21. 21

    Menaker, M. Hibernation–hypothermia: an annual cycle of response to low temperature in the bat Myotis lucifugus. J. Cell. Comp. Physiol. 59, 163–173 (1962)

    CAS  Article  Google Scholar 

  22. 22

    Pearson, E. W. Bats hibernating in silica mines in southern Illinois. J. Mammal. 43, 27–33 (1962)

    Article  Google Scholar 

  23. 23

    Davis, W. H. & Hitchcock, H. B. Notes on sex ratios of hibernating bats. J. Mammal. 45, 475–476 (1964)

    Article  Google Scholar 

  24. 24

    Henshaw, R. E. & Folk, G. E. Jr Relation of thermoregulation to seasonally changing microclimate in two species of bats (Myotis lucifugus and M. sodalis). Physiol. Zool. 39, 223–236 (1966)

    Article  Google Scholar 

  25. 25

    McManus, J. J. Activity and thermal preference of the little brown bat, Myotis lucifugus, during hibernation. J. Mammal. 55, 844–846 (1974)

    CAS  Article  Google Scholar 

  26. 26

    Nagorsen, D. W. Records of hibernating big brown bats (Eptesicus fuscus) and little brown bats (Myotis lucifugus) in Northwestern Ontario. Can. Field Nat. 94, 83–85 (1980)

    Google Scholar 

  27. 27

    Brack, V. Jr & Twente, J. W. The duration of the period of hibernation of three species of vespertilionid bats. I. Field studies. Can. J. Zool. 63, 2952–2954 (1985)

    Article  Google Scholar 

  28. 28

    Thomas, D. W. The physiological ecology of hibernation in vespertilionid bats. Symp. Zool. Soc. Lond. 67, 233–244 (1995)

    Google Scholar 

  29. 29

    Nagorsen, D. W. et al. Winter bat records for British Columbia. Northwest. Nat. 74, 61–66 (1993)

    Article  Google Scholar 

  30. 30

    Speakman, J. R. & Thomas, D. W. in Bat Biology (eds Kunz, T. H. & Fenton, M. B.) (Univ. Chicago Press, Chicago, in the press)

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We thank J. Umbanhowar for assistance with model sensitivity analysis as well as D. Kramer and K. McCann for comments on the presentation. This research was supported through a National Sciences and Engineering Research Council of Canada (NSERC) postdoctoral fellowship to M.M.H., and an NSERC research grant to D.W.T.

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Correspondence to Murray M. Humphries.

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Humphries, M., Thomas, D. & Speakman, J. Climate-mediated energetic constraints on the distribution of hibernating mammals. Nature 418, 313–316 (2002).

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