One interesting thing to look at is how wind farms have impacted wildlife, and what they have done to change designs so these impacts aren't as bad. Many birds and bats collide with the arms, and some bats experience a pressure change when flying near the moving arm that is enough to kill them even if they don't actually hit the arm. Many birds migrate at night and collisions happen frequently enough to cause concern.
Now wind farms are usually placed in areas out of the way of major migration routes.