The Indo-European flyway of migrating songbirds: Crossing the arid plains of central Eurasia

Abstract

The arid belt of Central Asia is a major barrier for many migrating songbirds. It has to be crossed by passerines that breed in Siberia and winter in Africa, but also by the species that breed in eastern Europe and winter in southern and south-eastern Asia. Many passerine migrants breeding in Siberia and wintering in Africa avoid crossing the deserts in autumn; instead, they make a detour to the north and northwest and fly north of the Caspian Sea. Here we show that some, but not all, European-Indian migrants (e.g. scarlet rosefinches and greenish warblers) in autumn also make a detour and fly towards the east north of the arid belt before crossing in its central or eastern part. Other species, which include e.g. red-breasted flycatchers, Blyth's reed warblers and possibly booted warblers, take the shortest route between their (north)east European breeding grounds and Indian winter quarters.