What can we learn from multi-species comparisons?

We apply main concepts of migration ecology to individual tracking data to analyse variation in migration performances within the Palearctic migration system. Herein we focus, amongst other things, on seasonal and sex specific timing of migration, spatial differences in migration pattern and how timing and spatial distributions affect subsequent annual cycle events. Furthermore, we relate migration timing as potential key factor to site specific phenology and compare the strength of this association and its consequences in ‘distinct’ migration strategies within and across species.

We capitalize from individual, geolocator or multisensory logger-based data sets of Palearctic migrants which have been collected during the last decade. Our multi-species approach requires a close collaboration with investigators of the original studies in terms of planning, analysis, and publication of results.

Our data sets allow for a better understanding of natural variation and mechanisms of Passerine migration. Multispecies comparisons set the basis for further detailed experimental studies on specific phenomena of long- and short-distance migration.

Migration of Afro-Palaearctic landbirds follows a longitudinally parallel leapfrog pattern, whereby birds track vegetation green-up in spring but depart before vegetation senescence in autumn. The continentality along migration routes and at breeding sites influences migration timing on a broad scale. We tested the concept of protandry, the earlier arrival of males at breeding sites, across the annual cycle. Protandry is not exclusively a reproductive strategy but rather occurs year-round. Main proximate determinants were sex-specific differences in departure timing and migration duration.