Meeting Abstract

S6.6  Tuesday, Jan. 5  Understanding the migratory orientation program in birds: extending laboratory studies to studying free-flying migrants in a natural setting THORUP, Kasper; University of Copenhagen kthorup@snm.ku.dk

For many years, orientation in migratory birds has primarily been studied in the lab. Though a lab-based setting enables easy manipulation of the environment, the lab-based findings must be investigated in the wild in free-flying birds to fully be able to understand how birds orient on migration. Despite the difficulties associated with following free-flying birds over long distances, a number of possibilities currently exist for tracking the sometimes even global journeys undertaken by migrating birds. Birds fitted with radio transmitters can either be located from the ground or from aircraft (conventional tracking), or from space. Alternatively, positional information obtained by onboard equipment (e.g. GPS units) can be transmitted to receivers in space. Use of these tracking methods has provided a wealth of information on migratory behaviors that are otherwise very difficult to study. Here, we will focus on the progress in understanding components of the migration system that has been achieved and can be expected in the future from tracking free-flying migrants in the wild. Such methods have been successfully applied to study orientation cue use in raptors (satellite telemetry) and thrushes (conventional), where the findings in the natural setting may not always be as expected from cage experiments. Furthermore, these methods have finally allowed for extension of the paradigmatic displacement experiments performed by Perdeck in 1958 on the short-distance, social migrant, the starling, to long-distance migrating storks and long-distance, non-socially migrating passerines providing new insights to nature of the migratory orientation system that enables experienced birds to navigate and guide inexperienced, young birds to their species-specific winter grounds.