Allometric scaling of maximum metabolic rate: the influence of temperature

Authors

  • C. R. White,

    Corresponding author
    1. Centre for Ornithology, School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
    2. School of Integrative Biology, The University of Queensland, St Lucia, 4072 QLD, Australia;
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  • J. S. Terblanche,

    1. Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa; and
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  • A. P. Kabat,

    1. Centre for Ornithology, School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
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  • T. M. Blackburn,

    1. Institute of Zoology, Zoological Society of London, Regent's Park, London NW1 4RY, UK
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  • S. L. Chown,

    1. Centre for Invasion Biology, Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa; and
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  • P. J. Butler

    1. Centre for Ornithology, School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
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*Correspondence author. E-mail: craig.white@uq.edu.au

Summary

  • 1Maximum aerobic metabolic rate, measured in terms of rate of oxygen consumption during exercise (inline image), is well known to scale to body mass (M) with an exponent greater than the value of 0·75 predicted by models based on the geometry of systems that supply nutrients.
  • 2Recently, the observed scaling for inline image (∝M0·872) has been hypothesized to arise because of the temperature dependence of biological processes, and because large species show a greater increase in muscle temperature when exercising than do small species.
  • 3Based on this hypothesis, we predicted that inline image will be positively related to ambient temperature, because heat loss is restricted at high temperatures and body temperature is likely to be elevated to a greater extent than during exercise in the cold.
  • 4This prediction was tested using a comparative phylogenetic generalized least-squares (PGLS) approach, and 34 measurements of six species of rodent (20·5–939 g) maximally exercising at temperatures from –16 to 30 °C.
  • 5inline image is unrelated to testing temperature, but is negatively related to acclimation temperature. We conclude that prolonged cold exposure increases exercise-induced inline image by acting as a form of aerobic training in mammals, and that elevated muscle temperatures of large species do not explain the scaling of inline image across taxa.

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