Artificial islands for the Black Terns

CABS project for the protection of endangered birds in Brandenburg and Saxony-Anhalt
Black terns have high demands on their breeding grounds: They must be undisturbed waters, not too shallow and not too deep, sunny, without currents and above all they must have one thing: Plenty of aquatic plants. The black beauties build their nests on dead plant parts that float on the surface of the water. This breeding preference is so rare today, the Black Tern has been brought to the brink of extinction. In the North German Plain about 1,000 to 1,300 pairs still breed today, in the last thirty years their population in Germany has decreased by more than 50 %.
The European comparison is also a real tragedy: In all Western and Southern European countries the Black Tern is in significant decline, only in Eastern Europe are the populations still relatively stable. But here, too, the large remaining natural landscapes are threatened by the intensification of agriculture, road construction and monoculture.

In order to support this highly endangered bird species, the Committee Against Bird Slaughter (CABS) has established a colony with artificial nesting aids in the nature reserve "Pritzerber See" - a off shoot of the Havel river, providing a shallow lake northwest of the city of Brandenburg - and on an old Elbe arm near Tangermünde. It all began with 30 small rafts that were deployed on Lake Pritzerberg in spring 2007. Little by little more islets were added here and on the Elbe near Tangermünde, and now there are more than 100.
The nesting aids must be reassembled each year by means of a rubber dinghy so that they are not destroyed by winter floods. The lightweight rafts are anchored to the bottom of the lake every spring with long strings that can compensate for fluctuations in water level after rainfall. The breeding rafts are dismantled for the winter.
The "Komitee-Seeschwalbenkolonie" is located directly on the edge of NABU's Havel renaturation project, which is unique in Europe. Between the Pritzerbe and the mouth of the Havel into the Elbe, 18,700 hectares of floodplain landscape will be restored to their natural state in the next few years. Numerous old and dead arms of the Havel will also be restored, in which the Black Tern will probably find natural breeding grounds again in the future. Until then, CABS will continue to expand the colony at Lake Prizerberg.