Flying, fasting, and feeding in birds during migration: a nutritional and physiological ecology perspective
Article first published online: 26 AUG 2004
Journal of Avian Biology
Volume 35, Issue 5, pages 377–393, September 2004
How to Cite
McWilliams, S. R., Guglielmo, C., Pierce, B. and Klaassen, M. (2004), Flying, fasting, and feeding in birds during migration: a nutritional and physiological ecology perspective. Journal of Avian Biology, 35: 377–393. doi: 10.1111/j.0908-8857.2004.03378.x
- Issue published online: 26 AUG 2004
- Article first published online: 26 AUG 2004
- Paper received 12 January 2004; manuscript revised 21 June 2004; manuscript accepted 18 July 2004.
Unlike exercising mammals, migratory birds fuel very high intensity exercise (e.g., flight) with fatty acids delivered from the adipose tissue to the working muscles by the circulatory system. Given the primary importance of fatty acids for fueling intense exercise, we discuss the likely limiting steps in lipid transport and oxidation for exercising birds and the ecological factors that affect the quality and quantity of fat stored in wild birds. Most stored lipids in migratory birds are comprised of three fatty acids (16:0, 18:1 and 18:2) even though migratory birds have diverse food habits. Diet selection and selective metabolism of lipids play important roles in determining the fatty acid composition of birds which, in turn, affects energetic performance during intense exercise. As such, migratory birds offer an intriguing model for studying the implications of lipid metabolism and obesity on exercise performance. We conclude with a discussion of the energetic costs of migratory flight and stopover in birds, and its implications for bird migration strategies.