When birds meet glass, the St. Louis Audubon Society is counting

For the last six years, the BirdSafe program incubated by the St. Louis Audubon Society has documented a deadly toll in St. Louis: bird collisions. With the Mississippi River flyway bringing flocks of birds through St. Louis during seasonal migrations, the region’s central corridor witnesses hundreds of birds dying after striking windows each year. In 2025, BirdSafe documented a record number of 547 bird collisions across select sites in downtown St. Louis and Clayton, with the goal of using the tally to push stakeholders for solutions.

According to Matt Barton, an urban conservation specialist at the St. Louis Audubon Society, national conversations about bird collisions inspired the start of BirdSafe in 2020. The year prior, a report by the Cornell Lab of Ornithology listed St. Louis in the top 10 most dangerous cities for migrating birds.

“Vocal members of [the] St. Louis Audubon Society wanted to get together and try to see what’s actually happening out there in St. Louis,” says Barton. 

The program has dramatically grown in the years since its founding. In 2025, BirdSafe conducted 130 surveys across downtown St. Louis and Clayton, with the help of over 45 volunteers. 

Sylvie Purkis, now a freshman at Metro High School, is one the youngest volunteers in BirdSafe. She joined the program in sixth grade, after encountering the “sparkbird”—in her case, a mountain bluebird, spotted during a family trip to Yellowstone—that drew her towards birding. 

“Normally, we get out there around six in the morning, so pretty early. BirdSafe gives you a map of all the buildings…and then you just walk around all accessible sides of those buildings,” Purkis explains. 

Volunteers photograph and document dead or injured birds at the sites during the surveys, which are conducted every other day during spring and fall migration seasons. Purkis recalls bringing an injured magnolia warbler to a rescue during one shift.

Jean Favara, a board member of the St. Louis Audubon Society, is one of the founders of BirdSafe. She explains that the survey sites focus on buildings with mirrored glass in proximity to green spaces, making them prone to collisions. 

“You have the double whammy of a lot of glass and mirror glass, which reflects the vegetation near buildings, and birds can’t tell whether that tree in the glass is a real tree or not,” says Favara. 

Glass infrastructure, however, is only part of the puzzle. “The primary drivers for these collisions are light pollution: light drawing birds into urban spaces while they’re on their migration routes overnight, and then the glass itself,” explains Barton. 

But with a clear roadmap of how to reduce bird collisions, Barton is optimistic about changing the paradigm. The St. Louis Audubon Society is a partner organization of Lights Out Heartland, a Midwest program that encourages buildings to limit lighting during migration seasons to reduce bird collisions. 

In 2021, the Audubon Society celebrated St. Louis County’s resolution committing to tackling bird mortality and reducing light pollution, followed by the City of Clayton the year after. According to Barton, partners including the Gateway Arch, St. Louis Zoo, and Washington University are committed to minimizing light pollution during migration seasons.  

Last year, Barton brought the conversation to a larger group of stakeholders, presenting BirdSafe’s findings to the Building Owners and Managers Association. “Since then, we have been in conversations with some of these buildings that we monitor around,” says Barton. 

In the 2025 survey, two sizable buildings downtown—Bank of America Plaza and UMB Bank— witnessed the highest number of collisions. (Bank of America referred questions to CBRE Global Commercial Real Estate Services, which owns the building. Neither they nor UMB Bank responded to our request for comment.)

Favara sees change in the St. Louis region as a “step by step” process, starting with data collection to create awareness and then advocate for action. Birders encourage people to make small changes in their own daily lives to help tackle bird collisions. 

“It’s not just big skyscrapers in downtown areas that have issues with collisions. The majority of collisions are happening at residential buildings, so [turning lights off at night] is something that people can implement in their own life as well,” says Barton. 

Susie Purkis, Sylvie’s mother, also volunteers for BirdSafe, and encourages St. Louisians to play their part in tackling bird collisions. 
“Sometimes it’s hard because you go from seeing these beautiful birds up in the trees looking at them through binoculars to seeing them after they hit a window…” she says of her work with BirdSafe. “Even individuals turning lights out or putting decals on their windows to make their windows more visible to birds to prevent bird collisions—everything is important. 
No matter how small or how big.”

Editor’s note: Due to a mixup, previous version of this story contained inaccurate information about the bird depicted in the photo. We regret the error.