Black-necked Grebes (Podiceps nigricollis) know how to use favorable conditions surprisingly spontaneously in individual years, as if “scouts” were permanently on the move, which guide other birds to new habitats and locations. One example is the spontaneous emergence of a breeding colony at the Alfsee in the Landkreis (district) Osnabrück in Lower Saxony in June 2011 with 52 pairs which tried to use the favorable conditions through the mass occurrence of emergent water plants. It goes without saying that not all breeding occurrences emerge and disappear so quickly; there are also numerous breeding sites that have been occupied for decades and are often located near colonies of gulls, especially those of the Common Black-headed Gull (Larus ridibundus).
One other example is an occurrence in southern Brandenburg. In a vast shallow lake area, the Rietzer See near Kloster Lehnin, the numbers are impressive since the beginning of counting and on April 13, 2012 more than 110 Black-necked Grebes were counted.
It was not until 2011 that the first Black-necked Grebes appeared at the Reckahner ponds, also in the municipality of Kloster Lehnin, but in a fish pond farm. Then there were no more reports for 7 years and then from 2018 onwards some reports, which then culminated in a Continue reading Distribution patterns of Black-necked Grebes