Genetic Determination of Migration Strategies in Large Soa-ring Birds: Evidence from Hybrid Spotted Eagles

Hereby we show that genetic determination in soaring birds is also more important than hitherto ascertained. We used GPS-telemetry to compare the autumn journeys and wintering ranges of two closely related large raptorial bird species (Lesser Spotted Eagle – 27, Greater Spotted Eagle – 21) and hybrids between them (14). That is remarkable part of GSEs and hybrids population on western margin of the range. Hybrids timed their migrations similarly to one parental species but had wintering distributions and home range sizes like the other. Tracking data was supported by ring recovery and habitat suitability modelling. These results suggest a strong genetic influence on migration strategy via a segregated dominance effect, although it does not rule out the contribution of social interactions. No differences between sexes was found. We wish maybe, to find easy solutions, but these appear to be complex.