Hundreds of migrating birds died during the night and early morning of September 14 and 15 after colliding with buildings at the World Trade Center complex (WTC) in New York City, according to the American Bird Conservancy (ABC). The organization, along with the New York City Audubon, and other partners, are working to engage with managers of the buildings at the WTC complex to remediate their glass, making the area safer for birds.

Because of stormy conditions on Tuesday night, night-migrating songbirds — including the Black-and-white Warbler, Northern Parula and Ovenbird — flew lower to the ground. Likely, they were attracted by bright artificial lights at the World Trade Center site, which, combined with strong winds, produced mortalities as birds tried to land, according to the ABC.

“Glass in the built environment is always dangerous to birds and unfortunately, birds are killed by collisions with glass every day. When bad weather brings birds down and lights bring them in, danger and mortality are increased,” says Christine Sheppard, ABC’s Bird Collisions campaign director.

“Turning off unnecessary lights can prevent bird deaths,” says Sheppard. “The problem here was a ‘perfect storm’ — high numbers of birds aloft, a storm bringing them close to the built environment, lights preventing them from navigating. And then glass waiting for them first thing in the morning.

“New York City’s Local Law 15, established in 2020 — requiring that all new buildings follow bird-friendly design guidelines and use bird-friendly glass — will definitely help going forward,” she said.