Courtship displays of Common Scoters Melanitta nigra were studied in a wintering concentration off Terschelling, Dutch Wadden Sea islands, on board MV Navicula in March 1991. Courting displays were found to occur both during day and night. One particular display was not previously described (cf. Bauer & Glutz von Blotzheim 1969, Cramp & Simmons 1977). A group of scoters, usually consisting of 1 adult female and about 10 drakes, suddenly takes off and starts swarming. The female, never leading but usually in second to fifth position, decides where to go and how to fly with all the males trying hard to follow and stay as close as possible to her. In the back of the group males leave, but new males join and the group may grow to about 40. Then the group suddenly alights, with all males behaving quite excitedly, sometimes close to the ship, apparently losing all shyness. In normal situations, Common Scoters do try to stay at least several hundreds of metres away from an approaching vessel. It is argued, that this type of behaviour is initialed by the female and occurs rather late in the wintering season when a female, having already chosen a partner, is unable to avoid the harassment of the many still unmated males.