Up to one billion birds are killed annually in the U.S. when they crash into glass buildings. The spring and fall migrations are especially treacherous times. Developers of New York’s planned 1,776 foot Freedom Tower, to be built on the former site of the World Trade Center, have enlisted an industrial ornithologist to advise them on making the new building bird-friendly. Recommendations include using less reflective glass and dimming the lights at dusk to avoid nighttime collisions by migrating birds. Read more about the Freedom Tower plans in the article Freedom Tower May Be Lifesaver for Birds.