Juvenile movement behaviour in a saturated population

We aim at investigating the factors shaping the ontogeny of movement behaviours in a dense population of Golden Eagles. Variation in the development of flight in the post-fledging dependency period can have consequences for later movement processes. A main focus will be on juvenile movement behaviour in space and time after departure from parental territories. In this period, the dense territories of conspecific breeding birds might affect natal dispersal movements, in addition to the distribution of important resources such as food and the energy landscape.

In collaboration with the Max Planck Institute for Animal Behaviour and the Konrad Lorenz Research Centre of the University of Vienna we tagged 35 juvenile Golden Eagles in Switzerland and 50 juveniles in Germany, Italy, and Austria. The solar-powered loggers transmit GPS positions and acceleration data, which provide information on the movements and behaviours of the juvenile eagles. In addition, behavioural observations and point counts serve to identify conspecific territories, quantify their effects on juvenile movements, and validate tracking data.

Golden Eagles depend on Alpine habitats, and therefore, Switzerland has a special responsibility for the species’ conservation in Europe. Despite the close to saturated population, the Golden Eagle remains a species of high national priority, and its population is classified as vulnerable in the Swiss Red List. Investigating the processes involved in the recruitment of this Alpine indicator species into a changing Alpine landscape goes beyond the species’ ecology itself and provides important insights into density-dependence of natal dispersal in long-lived species.

• Max Planck Institute of Animal Behavior
• Konrad Lorenz Research Center, University of Vienna

• Stiftung Yvonne Jacob