We compiled published values of mammalian maximum oxygen consumption during exercise and supplemented these data with new measurements of V O2,max for the largest rodent, 20 species of smaller-bodied rodents, two species of weasels and one small marsupial. Many of the new data were obtained with running-wheel respirometers instead of the treadmill systems used in most previous measurements of mammalian V O2,max. We used both conventional and phylogenetically informed allometric regression models…
Read moreWe compiled published values of mammalian maximum oxygen consumption during exercise and supplemented these data with new measurements of V O2,max for the largest rodent, 20 species of smaller-bodied rodents, two species of weasels and one small marsupial. Many of the new data were obtained with running-wheel respirometers instead of the treadmill systems used in most previous measurements of mammalian V O2,max. We used both conventional and phylogenetically informed allometric regression models to analyze V O2,max of 77 species' in relation to body size, phylogeny, diet and measurement method. Both body mass and allometrically mass-corrected V O2,max showed highly significant phylogenetic signals. The Akaike information criterion corrected for sample size was used to compare 27 candidate models predicting V O2,max. In addition to mass, the two best-fitting models included dummy variables coding for three species previously shown to have high V O2,max, and incorporated a transformation of the phylogenetic branch lengths under an OrnsteinUhlenbeck model of residual variation. We found no statistical difference between wheel-and treadmill-elicited values, and diet had no predictive ability for V O2,max. Averaged across all models, the allometric scaling exponent was 0.839, with 95% confidence limits of 0.795 and 0.883, which does not provide support for a scaling exponent of 0.67, 0.75 or unity. © 2013. Published by The Company of Biologists Ltd.