Birds from the Far East in Central Europe: a test of the reverse migration hypothesis

Every year birdwatchers throughout Europe record the arrival of a considerable number of vagrants from the eastern Palaearctic. We analysed the occurrence of such vagrants in Central Europe of the genera Phylloscopus, Turdus and Zoothera in Central Europe. Our results revealed that the occurrence of a species depended on total population size, but not on body size. Furthermore, the occurrence of species in Central Europe increased with distance between the breeding range and wintering range, but the distance between the breeding range and Europe had no effect. These results indicate that the migratory restlessness of species determines whether an East Asian species arrives in Europe. Overall, our data support the hypothesis that the migratory program determines vagrancy.