It's a bit odd that we hear a lot more about the ~300k birds killed annually by windmills than 7 million killed by communication towers (I didn't even know about this one). I would guess because windmills are a hotter political issue.
And that pales in comparison to the number of birds killed by glass. Estimates of 100 million to 1 billion birds annually in the US alone. Every time I hear bird-deaths as an argument against windmills I want to scream until I die. [1] http://www.msnbc.msn.com/id/4134773/ns/us_news-environment/t...
Apparently if you put a sticker of an eagle's silhuette on every couple of windows most birds will stay away and won't hit the glass. I see this mostly done on our motorways though ... never seen it on a skyscraper yet.