I've been posting about the problem of birds hitting windows for a long time, though not as long as Bill Watterson (see above). Recently I got to spend an afternoon with Dr. Dan Klem who is the leading researcher on this topic. He teaches at Muhlenberg College just up the road from me in Allentown. I've posted an interview with him over at Urban Birdscapes. So if you want to check out the latest on birds and windows, that's the place to be.