Between 140,000 and 573,000 birds die in a year from colliding with wind turbines in the U.S., a 2013 study estimated. Other studies estimate that other human-made structures and machines are much more deadly to the avian population:
- Roughly 6.8 million birds die from collisions with communications towers in North America.
- Between 12 million and 64 million die from collision with and electrocution by power lines in the U.S.
- Between 89 million and 340 million die from vehicle collisions on U.S. roads.
- Between 365 million and 988 million die from colliding with buildings and windows, "a major anthropogenic threat" according to the authors of that study.