Inheritance and learning in raptor migration

Every autumn, tens of thousands of soaring migrants - buzzards, sparrowhawks, harriers, kites and others - concentrate on the Falsterbo Peninsula on autumn migration. In a long-term program, we examine the migration strategies of a range of migrating raptor birds (osprey, marsh harrier, honey buzzard, common buzzard, hobby). We are particularly interested in differences in the migration of different age and sex classes, variation between years, and differences between species.
 
This particular project aims to obtain tracking records of the entire migration history of some individuals - from their first migration journey as juveniles and further on in their life as adults. Analyses of repeated journeys and of individual migration histories are fundamental for revealing the relative importance of inheritance and learning in bird migration. How is inherent spatiotemporal program complemented by imprinting and learning during the first and successive journeys? How do wind drift and other deviations during one journey affect succeeding journeys?

Larger sample of juveniles

Larger sample of juveniles

Due to a much higher mortality rate among juveniles, it is a much more difficult task to obtain multi-year migration data for individual juveniles than for adults. Hence, we wish to make a special effort during the coming years to obtain information about the entire migration history of individuals by carrying out GPS satellite tracking of a larger sample of juvenile ospreys to make sure that at least 5 are expected to survive several years into adulthood. Here a juvenile osprey is released that just has been fitted with a GPS-satellite transmitter. Photo: Roine Strandberg