Power and metabolic scope of bird flight: a phylogenetic analysis of biomechanical predictions

Summary, in English

For flying animals aerodynamic theory predicts that mechanical power required to fly scales as P proportional, variant m (7/6) in a series of isometric birds, and that the flight metabolic scope (P/BMR; BMR is basal metabolic rate) scales as P (scope) proportional, variant m (5/12). I tested these predictions by using phylogenetic independent contrasts from a set of 20 bird species, where flight metabolic rate was measured during laboratory conditions (mainly in wind tunnels). The body mass scaling exponent for P was 0.90, significantly lower than the predicted 7/6. This is partially due to the fact that real birds show an allometric scaling of wing span, which reduces flight cost. P (scope) was estimated using direct measurements of BMR in combination with allometric equations. The body mass scaling of P (scope) ranged between 0.31 and 0.51 for three data sets, respectively, and none differed significantly from the prediction of 5/12. Body mass scaling exponents of P (scope) differed significantly from 0 in all cases, and so P (scope) showed a positive body mass scaling in birds in accordance with the prediction.

• Author: Anders Hedenström
• Department/s: Evolutionary ecology; Animal Flight Lab
• Publishing year: 2008
• Language: English
• Pages: 685-691
• Publication/Series: Journal of Comparative Physiology A
• Volume: 194
• Issue: 7
• Links: http://dx.doi.org/10.1007/s00359-008-0345-z
• Document type: Journal article
• Publisher: Springer
• Topic: Biological Sciences
• Keywords: Bird flight energy cost - Metabolic scope - Aerodynamics - Phylogenetic contrasts - Scaling
• Status: Published
• Research group: Animal Flight Lab
• ISBN/ISSN/Other: ISSN: 1432-1351