Light oiling of feathers increases flight energy expenditure in a migratory shorebird.

Autor:	Maggini I; Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, ON, Canada N6G 1G9 ivan.maggini@vetmeduni.ac.at.; Konrad Lorenz Institute of Ethology, Department of Integrative Biology and Evolution, University of Veterinary Medicine, 1160 Vienna, Austria., Kennedy LV; Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, ON, Canada N6G 1G9., Macmillan A; Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, ON, Canada N6G 1G9., Elliott KH; Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, ON, Canada N6G 1G9., Dean K; Abt Associates, 1881 Ninth Street, Boulder, CO 80302, USA., Guglielmo CG; Department of Biology, Advanced Facility for Avian Research, University of Western Ontario, London, ON, Canada N6G 1G9.
Jazyk:	angličtina
Zdroj:	The Journal of experimental biology [J Exp Biol] 2017 Jul 01; Vol. 220 (Pt 13), pp. 2372-2379.
DOI:	10.1242/jeb.158220
Abstrakt:	Flying birds depend on their feathers to undertake most activities, and maintain them in peak condition through periodic molt and frequent preening. Even small exposures to crude oil reduce the integrity of feathers, and could impair flight performance. We trained wild western sandpipers ( Calidris mauri ) to perform endurance flights in a wind tunnel, and used magnetic resonance body composition analysis to measure energy expenditure after birds were exposed to weathered MC252 crude oil from the Deepwater Horizon oil spill. The cost of transport was 0.26±0.04 kJ km -1 in controls, and increased by 22% when the trailing edges of the wing and tail were oiled (<20% of body surface; considered light oiling). Additional crude oil on breast and back feathers (∼30% total surface; moderate oiling) increased the cost of transport by 45% above controls. Oiling tended to decrease flight control, and only half of moderately oiled birds completed the flight test. We then flew birds at a range of speeds to estimate basic kinematic parameters. At low speeds, light and moderately oiled birds had larger wingbeat amplitudes than controls, while moderately oiled birds showed greater wingbeat frequencies across all speeds, and a shift in optimal flight speed towards higher wind speeds. We suggest these changes reflect poorer lift production and increased drag on the wings and body. Oiling will increase the difficulty and energy costs of locomotion for daily and seasonal activities such as foraging, predator evasion, territory defense, courtship, chick provisioning, commuting and long-distance migration. These sub-lethal effects must be considered in oil spill impact assessments. Competing Interests: Competing interestsThe authors declare no competing or financial interests. (© 2017. Published by The Company of Biologists Ltd.)
Databáze:	MEDLINE
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