Effects of wind turbines on birds. What needs to be taken into account in Finland

The author examines the current knowledge on bird fatalities from wind turbines. As the number of turbines around the Finnish coast increases, concern has been voiced by some ornithologists for the safety of birds, particularly during migration. However, studies confirm that few birds collide with wind turbines during the day, with the exception of some large birds of prey that sometimes attempt to use the tower or blades for perching. At night the collision risk is somewhat higher, but average collision rates per kilometre of wind turbines placed in a row (including the space between individual machines) is no higher than that per kilometre of motorway, an acceptable figure in view of the relatively low numbers of machines compared to roads. Wind turbines can potentially do more serious damage to birds if they are erected too near large breeding concentrations, e.g. important coastal wetlands. Many groups of water and wading birds avoid feeding or nesting near turbines up to a range of 500-700 metres. (orig.)