The energetic cost of flight in a wind-tunnel was measured at various combinations of speed and flight angle from two species of bats whose body masses differ by almost an order of magnitude. The highest mean metabolic rate per unit body mass measured from P. hastatus (mean body mass, 0.093 kg) was 130.4 Wkg-1, and that for P. gouldii (mean body mass, 0.78 kg) was 69.6 Wkg-1. These highest metabolic rates, recorded from flying bats, are essentially the same as those predicted for flying birds of the same body masses, but are from 2.5 to 3.0 times greater than the highest metabolic rates of which similar-size exercising terrestrial mammals appear capable. The lowest mean rate of energy utilization per unit body mass P. hastatus required to sustain level flight was 94.2 Wkg-1 and that for P. gouldii was 53.4 Wkg-1. These data from flying bats together with comparable data for flying birds all fall along a straight line when plotted on double logarithmic coordinates as a function of body mass. Such data show that even the lowest metabolic requirements of bats and birds during level flight are about twice the highest metabolic capabilities of similar-size terrestrial mammals. Flying bats share with flying birds the ability to move substantially greater distance per unit energy consumed than walking or running mammals. Calculations show that P. hastatus requires only one-sixth the energy to cover a given distance as does the same-size terrestrial mammal, while P. gouldii requires one-fourth the energy of the same-size terrestrial mammal. An empirically derived equation is presented which enables one to make estimates of the metabolic rates of bats and birds during level flight in nature from body mass data alone. Metabolic data obtained in this study are compared with predictions calculated from an avian flight theory.
Metabolism during flight in two species of bats, Phyllostomus hastatus and Pteropus gouldii
S. P. Thomas; Metabolism during flight in two species of bats, Phyllostomus hastatus and Pteropus gouldii. J Exp Biol 1 August 1975; 63 (1): 273–293. doi: https://doi.org/10.1242/jeb.63.1.273
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Meet the JEB Editors @ SEB 2023
Come and meet the JEB team at the Society for Experimental Biology centenary conference from 4-7 July in Edinburgh, UK. Visit exhibition stand 13/15 to pick up JEB centenary goodies, including our new ‘100 years of discovery’ T shirt, and join our Meet the JEB Editors event on Thursday 6 July at 12.30 at Platform 5 to find out more about the journal and chat to Editors including EiC Craig Franklin, Monitoring Editors Sanjay Sane, Trish Schulte and John Terblanche and the in-house News and Reviews team.
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JEB@100: an interview with Monitoring Editor Katie Gilmour
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Centenary Review - Adaptive echolocation behavior
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