Moroccan Cormorants
Moroccan Cormorants Phalacrocorax p.maroccanus breed along the Maroccan and Mauretanian coasts. Nothing is known about this taxon’s movements ( see Cramp, 1977.Handbook of the Birds of the Western Palaearctic,Oxford University Press). The bird found on 7th March 2019 in Stellendam,The Netherlands may have joined the Cormorants which had spend the winter in Moroccan or Mediterranean waters on their way home to the breeding areas in NW Europe.
see also:
https://radioactiverobins.com/archive/otherseabirds/3-cormorants.htm
https://radioactiverobins.com/archive/otherseabirds/3a-cormorants-a.htm