With reference to your article, "Concern over eagle kills in Norway (Windpower Monthly, March 2006), high mortality rates of birds of prey (raptors) can be avoided. Wind farm developers should analyse literature on avian collisions. What can be learned by that is that hub height and rotor diameter determine the distance between ground and rotor swept area: insufficient space between ground and blades is the main reason for bird kills. The sweep zone is dangerous for some birds. If we check the data of Smøla Wind farm we will see that this simple rule is violated by turbine design. Distance between ground and blades should be more than 30 metres (it is better at more than 40 metres) to prevent birds from colliding with the blades.