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Deep, prolonged torpor by pregnant, free-ranging bats

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Abstract

Many mammals save energy during food shortage or harsh weather using controlled reductions in body temperature and metabolism called torpor. However, torpor slows offspring growth, and reproductive individuals are thought to avoid using it because of reduced fitness resulting from delayed offspring development. We tested this hypothesis by investigating torpor during reproduction in hoary bats (Lasiurus cinereus, Vespertilionidae) in southern Canada. We recorded deep, prolonged torpor bouts, which meet the definition for hibernation, by pregnant females. Prolonged torpor occurred during spring storms. When conditions improved females aroused and gave birth within several days. Our observations imply a fitness advantage of torpor in addition to energy conservation because reduced foetal growth rate could delay parturition until conditions are more favourable for lactation and neonatal survival.

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References

  • Bell GP (1990) Birds and mammals on an insect diet: a primer on diet composition analysis in relation to ecological energetics. Stud Avian Biol 13:416–422

    Google Scholar 

  • Cryan PM, Wolf BO (2003) Sex differences in the thermoregulation and evaporative water loss of a heterothermic bat, Lasiurus cinereus, during its spring migration. J Exp Biol 206:3381–3390

    Article  PubMed  Google Scholar 

  • Dausmann KH, Glos J, Ganzhorn JU, Heldmaier G (2004) Hibernation in a tropical primate. Nature 429:825–826

    Article  PubMed  CAS  Google Scholar 

  • Geiser F (1996) Torpor in reproductive endotherms. In: Geiser F, Hulbert AJ, Nicol SC (eds) Adaptations to the cold: 10th international hibernation symposium. University of New England Press, Armidale, pp 81–86

    Google Scholar 

  • Geiser F (2004) Metabolic rate and body temperature reduction during hibernation and daily torpor. Annu Rev Physiol 66:239–274

    Article  PubMed  CAS  Google Scholar 

  • Geiser F, Ruf T (1995) Hibernation versus daily torpor in mammals and birds: physiological variables and classification of torpor patterns. Physiol Zool 68:935–966

    Google Scholar 

  • Körtner G, Brigham RM, Geiser F (2001) Torpor in free-ranging tawny frogmouths (Podargus strigoides). Physiol Biochem Zool 74:789–797

    Article  PubMed  Google Scholar 

  • Lausen CL, Barclay RMR (2003) Thermoregulation and roost selection by reproductive female big brown bats (Eptesicus fuscus) roosting in rock crevices. J Zool (1987) 260:235–244

    Article  Google Scholar 

  • McKechnie AE, Wolf BO (2004) The energetics of the rewarming phase of avian torpor. In: Barnes BM, Carey HV (eds) Life in the cold: evolution, mechanisms, adaptation and application. Institute of Arctic Biology, University of Alaska, Fairbanks, pp 265–267

    Google Scholar 

  • Racey PA (1973) Environmental factors affecting the length of gestation in heterothermic bats. J Reprod Fertil Suppl 19:175–189

    PubMed  CAS  Google Scholar 

  • Racey PA, Swift SM (1981) Variation in gestation length in a colony of pipistrelle bats (Pipistrellus pipstrellus) from year to year. J Reprod Fertil 61:123–129

    Article  PubMed  CAS  Google Scholar 

  • Shump KA Jr, Shump AU (1980) Comparative insulation in vespertilionid bats. Comp Biochem Physiol A 66:351–354

    Article  Google Scholar 

  • Thompson SD, Nicoll ME (1986) Basal metabolic rate and energetics of reproduction in therian mammals. Nature 321:690–693

    Article  PubMed  CAS  Google Scholar 

  • Wang LCH (1989) Ecological, physiological and biochemical aspects of torpor in mammals and birds. In: Wang LCH (ed) Advances in comparative and environmental physiology. Springer, Berlin Heidelberg New York, pp 361–401

    Google Scholar 

  • Wilde CJ, Knight CH, Racey PA (1999) Influence of torpor on milk protein composition and secretion in lactating bats. J Exp Zool 284:35–41

    Article  PubMed  CAS  Google Scholar 

  • Willis CKR, Brigham RM (2003) Defining torpor in free-ranging bats: experimental evaluation of external temperature-sensitive radiotransmitters and the concept of active temperature. J Comp Physiol B 173:379–389

    Article  PubMed  CAS  Google Scholar 

  • Willis CKR, Brigham RM (2005) Physiological and ecological aspects of roost selection by reproductive female hoary bats (Lasiurus cinereus). J Mammal 86:85–94

    Article  Google Scholar 

  • Willis CKR, Lane JE, Liknes ET, Swanson DL, Brigham RM (2004) A technique for modeling thermoregulatory energy expenditure in mammals and birds. In: Barnes BM, Carey HV (eds) Life in the cold: evolution, mechanism, adaptation, and application. Institute of Arctic Biology, University of Alaska, Fairbanks, pp 209–220

    Google Scholar 

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Acknowledgements

We thank C. Turbill for comments and R. Fisher, Q. Fletcher, A. Karst, K. Kolar, S. Martinez, M. Ranalli and C. Voss for help in the field. This work was supported by the Natural Sciences and Engineering Research Council (Canada), Mountain Equipment Co-op, Saskatchewan Environment and Resource Management and the American Society of Mammalogists.

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Authors and Affiliations

  1. Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW 2351, Australia

    Craig K. R. Willis & Fritz Geiser

  2. Department of Biology, University of Regina, Regina, SK, Canada, S4S0A2

    R. Mark Brigham

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  1. Craig K. R. Willis
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  2. R. Mark Brigham
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  3. Fritz Geiser
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Correspondence to Craig K. R. Willis.

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Willis, C.K.R., Brigham, R.M. & Geiser, F. Deep, prolonged torpor by pregnant, free-ranging bats. Naturwissenschaften 93, 80–83 (2006). https://doi.org/10.1007/s00114-005-0063-0

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  • DOI: https://doi.org/10.1007/s00114-005-0063-0

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