Evolutionary Ecology of Mammalian Hibernation Phenology
Hibernation is assumed to have evolved in response to environmental energy and/or water shortages, yet the environment in which it has most often been studied is the laboratory. Our understanding of the ecological and evolutionary significance of natural hibernation expression thus lags behind the impressive body of work that has been done on its physiological and biochemical mechanisms. In this chapter, I review studies that have been done on phenological variation in wild populations and argue for a tightened focus on individual variation. Climate change is altering temporal resource distributions worldwide and the impact that this may have on populations will depend on their ability to adjust their phenologies through phenotypic plasticity and/or microevolution. Making predictions regarding these two phenomena requires detailed information on the environmental and genetic contributions to, and the fitness consequences of, phenological variation. I describe each of these components, in turn, and briefly explain the analytical procedures used to calculate them. Although, to date, empirical information of this sort is relatively sparse for wild hibernators, recent studies have begun to provide it and the theoretical and analytical tools with which to undertake further study are becoming increasingly accessible. Through their application, a more thorough understanding of the role hibernation plays in the natural ecology of mammalian populations, and how these populations may be affected by climate change should be attainable.
KeywordsPhenotypic Plasticity Torpor Bout Phenological Trait Circannual Rhythm Phenological Variation
My research on hibernation phenology has been supported by the Royal Society of London and the Alberta Conservation Society, as well as, grants from the Agence Nationale de la Recherche of France (to Anne Charmantier) and the Natural Science and Engineering Research Council of Canada (to Stan Boutin).
- Endler JA (1986) Natural selection in the wild. Princeton University Press, PrincetonGoogle Scholar
- Falconer DS, Mackay TFC (1996) Introduction to quantitative genetics, 4th edn. Longman, HarlowGoogle Scholar
- French AR (1988) The patterns of mammalian hibernation. Am Sci 76:569–575Google Scholar
- Geiser F, Ruf T (1995) Hibernation versus daily torpor in mammals and birds: physiological variables and classification of torpor patterns. Physiol Zool 68:935–966Google Scholar
- Gummer DL (2005) Geographic variation in torpor patterns: the northernmost prairie dogs and kangaroo rats. PhD thesis. University of Saskatchewan, SaskatoonGoogle Scholar
- IPCC (2007) Summary for policymakers. In: Solomon S, Qin D, Manning M, Chen Z, Marquis M, Averyt KB, Tignor M, Miller HL (eds) Climate change 2007: the physical science basis. Contribution of working group I to the fourth assessment report of the intergovernmental panel on climate change. Cambridge University Press, CambridgeGoogle Scholar
- Lovegrove BG (2000) Daily heterothermy in mammals: coping with unpredictable environments. In: Heldmaier G, Klingenspor M (eds) Life in the cold. Springer, Berlin, pp 29–40Google Scholar
- Lynch M, Walsh B (1998) Genetics and the analysis of quantitative traits. Sinauer Associates, SunderlandGoogle Scholar
- Pigliucci M (2001) Phenotypic plasticity. John Hopkins University Press, BaltimoreGoogle Scholar
- Rismiller PD, McKelvey MW (1996) Sex, torpor and activity in temperate climate echidnas. In: Geiser F, Hulbert AJ, Nicol SC (eds) Adaptations to the cold: tenth international hibernation symposium, University of New England Press, Armidale, pp 23–30Google Scholar
- Wang LCH (1989) Ecological, physiological and biochemical aspects of torpor in mammals and birds. In: Wang LCH (ed) Comparative and environmental physiology. Animal adaptation to cold, vol 4. Springer, Berlin, pp 361–401Google Scholar