GPS tracking reveals new insights into the complexity of Eurasian wigeon (Mareca penelope) migration along the East Atlantic Flyway

Abstract

Successful conservation and management actions to safeguard migratory huntable waterbirds require knowledge of their spatio-temporal distributions and migration patterns throughout the annual cycle. Such actions are challenging, because migration patterns within a population can vary, for example, due to migratory barriers and sex-specific factors. We studied individual migratory patterns of East Atlantic flyway Eurasian wigeon (Mareca penelope), using GPS-tracking data from birds caught during spring in central and northern Europe. We found complex migratory patterns and differences in the spring migration of wigeon captured in central and northern Europe. These wigeon migrated south and north of the Baltic Sea, respectively, despite the Baltic Sea presenting no barrier to the population. Wigeon captured in central Europe moved northeast towards northern Russia, differing from movements of the birds captured in northern Europe, which were more varied and tended to migrate toward the northeast and northwest. Autumn migration orientation of birds from both capture areas was towards the southwest, resulting in Scandinavian breeding birds undertaking loop migration. Moult migrating males moved further during the summer than females, reducing migratory connectivity among males and reflecting sex-specific differences in the migratory behaviour of Eurasian wigeon. Our results confirm that individual migratory patterns of Eurasian wigeon show more diversity than expected from ring recovery data, suggesting that successful management at flyway-population level needs more detailed information to support management planning.