Abstract
Morning and evening flights of Whooper Swans (Cygnus cygnus) wintering near Overgaard, in eastern Jutland, Denmark, were studied to assess the potential risk of collisions with medium sized or with large turbines, should a proposed wind park be developed in the area. The birds could be particularly prone to collisions during evening flights, as these took place in rather poor light conditions. Recorded heights of swan flights indicated that a park consisting of medium sized wind turbines would be more critical in terms of collision risk than one with large turbines, with 38% of observed individuals flying within height range of the rotors in the former, only 13% in the latter.