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The consequences of climate-driven stop-over sites changes on migration schedules and fitness of Arctic geese

journal contribution
posted on 2008-07-01, 00:00 authored by S Bauer, M van Dinther, K A Høgda, Marcel KlaassenMarcel Klaassen, J Madsen
1. How climatic changes affect migratory birds remains difficult to predict because birds use multiple sites in a highly interdependent manner. A better understanding of how conditions along the flyway affect migration and ultimately fitness is of paramount interest.

2. Therefore, we developed a stochastic dynamic model to generate spatially and temporally explicit predictions of stop-over site use. For each site, we varied energy expenditure, onset of spring, intake rate and day-to-day stochasticity independently. We parameterized the model for the migration of pink-footed goose Anser brachyrhynchus from its wintering grounds in Western Europe to its breeding grounds on Arctic Svalbard.

3. Model results suggested that the birds follow a risk-averse strategy by avoiding sites with comparatively high energy expenditure or stochasticity levels in favour of sites with highly predictable food supply and low expenditure. Furthermore, the onset of spring on the stop-over sites had the most pronounced effect on staging times while intake rates had surprisingly little effect.

4. Subsequently, using empirical data, we tested whether observed changes in the onset of spring along the flyway explain the observed changes in migration schedules of pink-footed geese from 1990 to 2004. Model predictions generally agreed well with empirically observed migration patterns, with geese leaving the wintering grounds earlier while considerably extending their staging times in Norway.

History

Journal

Journal of animal ecology

Volume

77

Issue

4

Pagination

654 - 660

Publisher

Wiley

Location

Oxford, England

ISSN

0021-8790

eISSN

1365-2656

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2008, The Authors