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.

Seventy percent of bird species in the U.S. are migratory, and more than 80% of those migrate at night. Urban light pollution attracts avian travelers, leading them to crash into buildings.

Strategies to prevent these usually fatal collisions include constructing bird-friendly buildings with patterned glass or dimmer lights. Lawmakers in New York and Chicago are considering legislation to improve bird safety into new building rules.

New York City has two very large buildings dedicated to answering the 911 calls of its five boroughs. With more than 11 million emergency calls annually, it makes perfect sense. The second of these buildings, the Public Safety Answering Center II (PSAC II) is located on a nine-acre parcel of land in the Bronx. It’s an imposing 450,000 square-foot structure—a 240-foot-wide by 240-foot-tall cube. The gleaming aluminum cube risesthe equivalent of 24 stories from behind a grassy berm, projecting the unlikely impression that it might actually be floating. Like most visually striking structures, the building has drawn as much scorn as it has admiration.