Cats, cars, buildings and vehicles kill about 6,000 times more birds than wind turbines do. The biggest killer of birds in the U.S. by a long shot is domestic cats. After cats, building collisions due to glass (599 million bird deaths annually, on average) and vehicle collisions (214.5 million annually) pose the second and third biggest threats to birds. Poison kills an estimated 72 million birds each year, and collisions with electrical lines result in 25 million deaths annually. Then, way down at No. 9 on the list of threats to birds is wind turbines, which caused an average of 234,012 bird deaths annually. Audubon and other conservation groups have been working with wind energy companies to study bird deaths and other effects on wildlife, and through their bird-monitoring efforts, we’re learning more and more about how to keep birds safe around turbines. Sometimes, it’s as simple as changing the height of the wind turbine to avoid the altitudes birds migrate at and where they forage for food.