De herkenning van Aalscholver Phalacrocorax carbo en kuifaalscholver Strictocarbo aristotelis in de hand

Numbers of Cormorants have increased dramatically along the Dutch coast, following the enormous expansion of its inland population and the establishment of several colonies along the coast. So far, both Cormorants and Shags were quite rare as beached birds in the Netherlands, but this situation is now changing rapidly. Parallel with the increase of Cormorants in Dutch coastal waters have Shags been seen and found dead more frequently than before. Because both species, in particular immature specimens, are not easy to tell apart in the hand, an update of identification keys may be useful. This note is designed to aid participants in beached bird surveys to correctly identify the species, or perhaps subspecies, and to try and determine the age and sex of the birds in the hand. In de Nederlandse kustwateren is de Aalscholver Phalacrocorax carbo de laatste 15 jaren geweldig in aantal toegenomen. Niet alleen heeft deze soort zich als broedvogel aan de kust gevestigd, maar ook is het aantal op zee foeragerende Aalscholvers drastisch toegenomen. Plaatselijk worden nu al vissende groepen gezien van enkele duizenden exemplaren groot, een beeld dat tot dusverre slechts van het IJsselmeer bekend was.