Cormorants, egrets, helping each other

By Harvey van Diek, SOVON Vogelonderzoek in the Netherlands:

Lately, people can see a special phenomenon in the Ooijpolder near Nijmegen. Great cormorants and great egrets have joined forces in fishing.

In a small pond, about 30 by 30 meter, in the early morning scores of cormorants are fishing together. Hunting together increases chances of success. It is known just comparatively recently that cormorants fish together; it was seen for the first time in the Naardermeer.

Meanwhile, great egrets have discovered this special spectacle as well. Sometimes, on the banks of the pond, about 20 egrets stand waiting patiently until the cormorants have driven the fish so far that they almost literally swim into the eager waiting egrets’ bills. On the other hand, the great egrets drive the fish which they do not catch, back to the cormorants’ bills. Let us say: a win-win case.

Ooijpolder biodiversity: here.