Chicago, Houston, and Dallas deemed ‘most dangerous cities for migratory birds’

Collisions with buildings kill an estimated 600 million birds in the U.S. every year, according to the Cornell Lab of Ornithology.

The top three most dangerous cities for bird collisions—Chicago, Houston, and Dallas—are located within the heart of North America’s most trafficked aerial corridors, according a new Cornell study.

That fact, along with their considerable size, makes these cities dangerous to migrating birds in the spring and fall.