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The relevance of environmental conditions for departure decision changes en route in migrating geese

Bauer, S. and Gienapp, P. and Madsen, J. (2008) The relevance of environmental conditions for departure decision changes en route in migrating geese. Ecology, 89, 1953-1960. ISSN 0012-9658.

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Official URL: http://dx.doi.org/10.1890/07-1101.1

Abstract

The timing of life-cycle events crucially influences fitness, particularly in migratory birds, which visit chains of sites with varying seasonality. Here, we used a proportional hazards model to identify local environmental factors, which a long-distance migrant, the Pink-footed Goose (Anser brachyrhynchus), uses for departure decisions on multiple sites along its spring flyway from Denmark via Norway to Svalbard. Our results not only identified day length, local accumulated temperature, and their interaction as likely candidates, but also (more importantly) showed for the first time that their relevance changes en route. The results suggest that the birds switch on a “migratory program” in their wintering grounds, with day length providing general information on time of the year and integrated temperatures providing information on larger scale climate trends. Thereafter, on the stopover sites, local accumulated temperatures allow the geese to infer information on the advancement of spring, which is then used to adjust the speed of progressing northward.

Item Type:Article
Institutes:Nederlands Instituut voor Ecologie (NIOO)
ID Code:4806
Deposited On:30 Sep 2009 02:00
Last Modified:14 Oct 2013 12:52

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