Understanding the evolutionary potential and trajectories of migratory behaviour requires detailed knowledge of the patterns, sources, and consequences of variance in the migratory phenotype. Ideally, one would partition this variance into its underlying components, and learn which parts are underpinned by a genetic basis, which parts result from parental or other natal effects, and which parts are shaped by previously or currently experienced environmental conditions. In a next step, the variance in each of these parts could then be related to variance in fitness, to learn how selection acts on migratory behaviour and whether any response to selection can be expected. 

Using light-level geolocators (Kürten et al. 2019), we have so far collected 284 tracks of migratory journeys performed by 140 Banter See common terns, breeding in our long-term study population located at the Banter See (Kürten et al. 2022). Since almost all of these birds are of known sex, age and ancestry and since detailed information on their natal conditions, as well as annual local return, phenology and reproductive performance is available, assessing the causes and consequences of variance in their migratory phenotype is now within reach.

This project is part of the SFB 1372 Magnetoreception and Navigation in Vertebrates