Several gulls showed the same strange behaviour just after they had flown up from a gathering place on the river. Apparently, after having gained some hight, they suddenly stopped and seemed to perform a strange 'sur place' in they air, while they were violently shaking their feathers dry. They often repeated this a few times, before flying to their sleeping roosts. Some individuals seemed to give some weird footkicks in the air, before scratching their plumage with their feet. This inidviual is frozen by the rapid shutter while he was shaking himself dry in the air.