I just attended a slideshow on wind turbines in Pennsylvania and the damage they might do to our songbirds and raptors. Basically, energy companies want to put long lines of 70-80 meter-diameter turbines on every ridgetop in the central part of PA. That, according to the lecturer from the Audubon Society, could negatively impact every species of bird (not to mention mammals and snakes) in our state, essentially changing migratory routes and causing unknowable species effects.
It was a pretty scary lecture. One slide presented the number of birds killed by a communication tower on one foggy night. The tower was under 200 feet tall, so it has a steady (non-blinking) white light at the top. On a foggy night, it's like a flame drawing moths--over 400 songbirds were killed on one night in 2003. The slide even presented little bird carcasses, which really hit me hard.
If we allow these wind turbines to line our mountain ridges, in combination with the communication towers and other structures, we could see a massive drop in bird population.
Definitely a thought-provoking presentation, and one that more people need to see.