The Annual Cycle of German Adult Ospreys

During 1995 – 2011 we marked 28 adult Ospreys in NE-Germany with satellite tags working up to eight years.

All except three males wintered in West Africa. The migratory paths followed while in Europe seemed much straighter and more directional compared to the migratory paths followed in Africa. This pattern was related to wind conditions, whereby individuals drifted with winds as they crossed the Sahara, then compensated as they approached their destination causing a more diffuse pattern in migratory paths.

Consequently, individuals were fairly consistent in their use of routes between years in Europe, but not in Africa. Males started their autumn migration at the very end of the breeding season when the young have left, whereas females typically commenced migration much earlier, long before the young became independent. In contrast, the timing of the onset of spring migration showed little variation in either sex. However, while males showed little variation in arrival time on the breeding grounds, female arrival times were more variable.

The difference between the sexes in the variance in arrival dates is perhaps due to the pressure on males to arrive at breeding places early in order to find and defend a high-quality breeding territory.

The results will be presented at the European User Conference on Argos Wildife.