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Metabolic constraints on long-distance migration in birds

Klaassen, M.R.J. (1996) Metabolic constraints on long-distance migration in birds. Journal of Experimental Biology, 199, 57-64. ISSN 0022-0949.

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Official URL: http://jeb.biologists.org/content/199/1/57.abstract

Abstract

The flight range of migrating birds depends crucially on the amount of fuel stored by the bird prior to migration or taken up en route at stop-over sites. However, an increase in body mass is associated with an increase in energetic costs, counteracting the benefit of fuel stores. Water imbalance, occurring when water loss exceeds metabolic water production, may constitute another less well recognised problem limiting flight range. The main route of water loss during flight is via the lungs; the rate of loss depends on ambient temperature, relative humidity and ventilatory flow and increases with altitude. Metabolite production results in an increased plasma osmolality, also endangering the proper functioning of the organism during flight. Energetic constraints and water-balance problems may interact in determining several aspects of flight behaviour, such as altitude of flight, mode of flight, lap distance and stop-over duration. To circumvent energetic and water-balance problems, a bird could migrate in short hops instead of long leaps if crossing of large ecological barriers can be avoided. However, although necessitating larger fuel stores and being more expensive, migration by long leaps may sometimes be faster than by short hops. Time constraints are also an important factor in explaining why soaring, which conserves energy and water, occurs exclusively in very large species: small birds can soar at low speeds only. Good navigational skills involving accurate orientation and assessment of altitude and air and ground speed assist in avoiding physiological stress during migration. [KEYWORDS: migration; energetics; water balance; fuel stores time minimization; allometric relationships; flight altitude; navigation; birds Catbird dumetella-carolinensis; optimal fat loads; flight-muscle; body-mass; spring migration; water; requirements;adaptations; reserve; storage]

Item Type:Article
Institutes:Nederlands Instituut voor Ecologie (NIOO)
ID Code:10408
Deposited On:25 Nov 2011 01:00
Last Modified:31 Mar 2014 10:41

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