Songbird migration

Bird migration over the open sea (BIRDMOVE)

Institut für Vogelforschung „Vogelwarte Helgoland“

The German sea areas are regularly flown over in large numbers of land birds on their migrations between the breeding areas and the resting and wintering areas. The spectrum of species involved ranges from the smallest songbirds to large birds such as geese and cranes. While general trajectories and times are well described for many species, surprisingly little is known about individual movements of individual birds. Why, for example, chooses a monk warbler to take the direct route across the open sea, while another conspecific prefers to pull along the shoreline? These unanswered questions are particularly prevalent among songbirds migrating mainly at night, too small and too light to be equipped with GPS transmitters.

The BIRDMOVE project uses a network of automatic receiving stations in the area of ​​the German Bight ( in combination with radio-telemetry transmitters weighing approx. 0.25 grams. These transmitters, carried by the birds as a backpack, can be located by the receiving stations. The antennas on the two research platforms FINO1 and FINO3 are an important addition to the network on the coast. With the help of the network, individual movement patterns of small songbirds in the area of ​​the German Bight can be traced for the first time with high spatial and temporal resolution.

The Federal Agency for Nature Conservation is funding the project with funds from the federal budget.

Activities and goals

Various songbird species are equipped with miniaturized radio telemetry transmitters. These send a coded signal within a few seconds, which can be individually assigned to each station. The signal itself is very weak (for comparison: the transmission power of a mobile phone is 500 times higher), but is sufficient to be recorded by the antennas over several kilometers. , The birds selected for the study belong to the medium and long-distance tractors. Middle-stretchers are e.g. Blackbird, robin and song thrush. They move across the German Bight and spend the winter in Europe. The long distance trains, e.g. Pied flycatcher, redstart and whitethroat, wintering south of the Sahara.

The aim of the project is to get a more accurate picture of the individual circumstances, such as the physical condition of a bird, and external conditions such. As the weather to win, which are linked to individual route decisions. In view of the numerous offshore wind farms that are already being operated in the German Exclusive Economic Zone and are still to be created, the study also offers the opportunity to better estimate the potential danger of these new structures for songbirds migrating at night. Thus, the nature conservation evaluation of possible effects of offshore wind farms can be further improved.