April 2, 2019 –  An estimated 600 million birds die from building collisions every year in the U.S., and research from the Cornell Lab of Ornithology offers one explanation for it.A team led by Kyle Horton, a Rose postdoctoral fellow at the lab, ranked metropolitan areas where, due to a combination of light pollution and geography, birds are at the greatest risk of becoming attracted to and disoriented by lights and crashing into buildings.