Migratory birds face increasing environmental challenges across their annual cycles. Decades of research into migration ecology have shown that ecological conditions in non-breeding and stopover areas influence the time and performance of spring migration. Food quality and availability are critical for migratory birds to fuel their long journeys toward the breeding areas. Local weather conditions, particularly wind, are another essential cue for departure, especially during long water crossings. Thus, conditions at non-breeding grounds can have carry-over effects on pre-breeding migration success. Recent studies have revealed a growing temporal overlap of multiple species in arrival at key stopover sites during migration, suggesting that co-migration may enhance survival by enabling the sharing of navigation cues and reducing the predation risk. While temporal co-occurrence at stopovers may reflect similar ecological needs, how this synchrony arises as collective responses to changing environmental conditions, triggering the formation of migratory communities, remains poorly understood.

Along the Afro-European flyway, many landbirds cross the Mediterranean Sea in a single nocturnal flight of more than 500 km, without a chance to rest or refuel. Migrants may rely on high energy reserves and select meteorological conditions before departing. However, less is known about the effects of the weather experienced over the sea route.

Building on previous fellowship projects (DOC ÖAW and Marietta Blau OeAD), this research aims to integrate empirical work into a novel conceptual framework viewing spring migration as both an individual and a community ecological process. The main question is investigating how non-breeding ecology in sub-Saharan areas and weather conditions experienced while crossing the sea influence the timing, physiology and co-occurrence of several long-distance migratory bird species during pre-breeding migration. In the long run, this project will reveal how migratory birds adapt to environmental instability, providing essential insights for developing conservation strategies for declining species.