Migration routes and wintering areas of Willow Warblers Phylloscopus trochilus (L.) ringed in Fennoscandia

Abstract

Long distance (>400 km) ringing recoveries of Willow Warblers from Norway, Sweden and Finland were analysed. Southern Swedish and Norwegian birds migrate southwest to wintering areas around the Gulf of Guinea in Africa, whereas northern Scandinavian and Finnish populations migrate south-southeast to wintering grounds in Central, East and South Africa . Juveniles leave the natal area before adults but, due to a slow beginning, the adults pass them by the end of August. Migration seems to be faster over continental Europe, with retardation at the Mediterranean. During spring migration at least birds of northern origin seem to take a more easterly track, flying east of the Mediterranean Sea. Migration direction for juveniles showed a greater dispersion around the mean than for adults .