More Than 1,000 Birds Were Killed or Injured in Window Collisions Around Chicago Over the Weekend

On the evening of October 16, more than five million birds are estimated to have flown through Cook County, which includes Chicago. They were propelled by favorable winds brought by a cold front

Sarah Kuta | Daily Correspondent

October 22, 2026 10:00 a.m.

Wildlife advocates are sounding the alarm after more than 1,000 birds were killed or injured in window collisions in the Chicago area last weekend, reports Fox 32 Chicago’s Nic Flosi.

Volunteers with the nonprofit Chicago Bird Collision Monitors spent October 17 and 18 rescuing wounded birds and collecting the bodies of dead ones in downtown Chicago and the northern suburb of Evanston.

“We’d pick up a bird at a building, go around that building, and immediately find another,” Annette Prince, director of Chicago Bird Collision Monitors, tells the Chicago Sun-Times’ Kaitlin Washburn. “We had birds hitting the glass windows over our heads.”

Prince says the more than 1,000 birds collected by volunteers likely represent only a fraction of those injured or killed during this year’s fall migration—or even over the weekend. They searched a small area, and they can “only find what’s on the ground,” Prince tells WTTW’s Patty Wetli. Many more birds probably go undiscovered, she says.

“We don’t even know the full extent, and that’s very sobering,” she adds. “What’s heartbreaking to us is this happens year after year.”

More than five million birds flew through Cook County, which includes Chicago, on the evening of October 16, according to the Cornell Lab of Ornithology’s BirdCast, which uses weather radar to detect and predict migratory activity. That huge number of birds coincided with a cold front, which brought favorable northerly tailwinds that can help push birds south. Across the country, more than one billion migratory birds were estimated to have taken flight that night.

Chicago is located along the Mississippi Flyway, a major migratory corridor for millions of birds traveling between North, Central and South America every spring and fall. But the city’s abundance of windows and artificial lights can make it a hazardous place for birds to navigate.

Birds often don’t see transparent glass, or they mistake its reflections of the surrounding scenery for a clear path forward. As a result, they can end up crashing into windows while traveling at speeds of up to 30 miles per hour, which can cause death, internal bleeding, concussions or other injuries. Artificial lights can also attract and disorient birds, increasing the risk of collisions, particularly at night, when many species migrate.

The birds that make it to Chicago every spring and fall, Prince tells WTTW, are “fit and strong.” But the city’s lights and windows are “taking out the best members,” she says. “They were doing everything right.”

Wildlife advocates say these deaths are largely preventable, an especially urgent concern at a time when bird populations face mounting threats. North America has lost around three billion birds since 1970, a figure that represents about 29 percent of the continent’s population, or more than one in four birds. In many places, the rate of decline is accelerating, likely due to warming temperatures and intensive agriculture, research suggests.

Chicago has seen high numbers of deadly bird collisions before. In October 2023, nearly 1,000 birds died in a single night after crashing into McCormick Place Lakeside Center, an event venue with a primarily glass facade.

Ahead of the 2024 fall migration, the building’s managers spent $1.2 million installing a special, polka-dot-covered film designed to help birds better differentiate between windows and open air. The center also vowed to implement other bird-safe measures, such as switching off non-essential exterior lights and closing drapes and blinds at night. Those efforts led to a more than 90 percent reduction in bird collision deaths during the following autumn season.

Wildlife advocates would like Chicago’s leaders to mandate such bird safety design measures for all new and renovated buildings. They’re pushing city councilors to adopt a bird-friendly building ordinance that’s currently undergoing language revisions in the city’s zoning committee, per the Chicago Tribune’s Adriana Pérez. Similar laws have been passed in other major cities, including New York City and Washington, D.C.

Birds “have a right to migrate and live and fly through our city without unnecessary harm,” Jennifer Bell, a Chicago Bird Collision Monitors volunteer who estimates she has collected more than 350 birds since September on her own, tells Block Club Chicago’s Janelle Mella. “We are causing unnecessary harm by continuing to build all of these glass buildings.”