Migration, wing morphometry and wing moult in Spanish and House Sparrows from the eastern Balkan Peninsula

Abstract

On the Balkan Peninsula, migratory Spanish Sparrows breed sympatrically with resident House Sparrows. While the two species share many biological and ecological traits, migratory patterns and adaptions to migratory lifestyle of the Spanish Sparrow are unknown. We tracked a Spanish Sparrow across its 1800 km long migration from Bulgaria to the nonbreeding sites in the Nile Delta. Stopovers were situated in western Turkey, before and after the 12 h-nonstop flights across the Mediterranean Sea. We show similar wing morphology in Spanish and House Sparrows indicating little adaptation to migration. However, Spanish Sparrows moult primaries earlier and faster allowing for timely migratory departure.