Erni, Birgit; Liechti, Felix; Bruderer, Bruno - In: Behavioral Ecology 16 (2005) 4, pp. 732-740
Large ecological barriers such as oceans and deserts have considerably shaped the migratory strategies of birds. The ecological barriers posed by the Alps, the Mediterranean Sea, and the Sahara seem to prevent most long-distance migrants from flying on a direct southward course from Europe to...