Ducks, geese, whoopers, sparrows, seagulls, warblers, hawks, etc can avoid them during the day, but its at night when they get chopped up. Many species migrate at night and they usually don't have any obstacles to avoid. Cell towers kill the hell out of birds as well, even with the lights on them. Especially along the coast, the trans-Gulf migrants just made a hell of a flight across a large body of water only to get chopped up by a big fan
whats ironic is that there are so many oil platforms in view of where they are wanting to put these things