Journal Article

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

Van Dinther, Martijn, Madsen, Jesper, Klaassen, Marcel, Bauer, Silke, Høgda, Kjell-Arild

2008

Overview

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.

• Publisher: Oxford, UK : Blackwell Publishing Ltd,British Ecological Society,Blackwell Publishing Ltd,Blackwell
• Subject: Animal and plant ecology / Animal ecology / Animal Migration / Animal Migration - physiology / Animal migration behavior / Animal, plant and microbial ecology / Animals / Anser / Anser brachyrhynchus / Aquatic birds / Arctic region / Aviculture / behaviour-based model / Biological and medical sciences / Birds / Breeding sites / Climate / Climate change / Climate Ecology / dynamic models / Ecology / energy expenditure / Energy Metabolism / Energy Metabolism - physiology / Female / food availability / Food Supply / Fundamental and applied biological sciences. Psychology / Geese / Geese - physiology / General aspects / Male / migratory behavior / Migratory birds / Modeling / Norway / onset of spring / phenology / physiology / prediction / Risk aversion / Seasonal migration / Seasons / spring / Stochastic models / Stochastic Processes / stochastic-dynamic programming / stopover sites / Waterfowl / Western European region / wintering grounds