St. Louis is the sixth-most dangerous city in the U.S. for fall migratory birds, according to the Cornell Lab of Ornithology. Many species of birds are drawn to the light of the region’s urban areas, where their chances of hitting a building increase.
“There's the issue of transparent glass, where birds don't realize it's there and try to fly through it,” said Matt Barton, urban conservation specialist with the St. Louis Audubon Society. “There's also the issue of really reflective glass [that reflects] the environment around them. They think perhaps they can fly to a tree that's nearby, but it's actually a reflection.”
The St. Louis Audubon Society launched BirdSafeSTL in fall 2020 to gather more data and to promote solutions to prevent building strikes. Since then, Audubon staff and volunteers have recorded more than 1,500 building-related bird fatalities in downtown St. Louis and downtown Clayton alone. It’s estimated that nearly 1 billion birds are killed by hitting buildings each year.
The problem can be mitigated through anti-strike window decals, as well as the use of blinds and curtains, which make windows more visible to birds. Another way to support migratory bird populations is to limit light pollution at night, when birds are doing most of their flying.
“During migration, [birds use] celestial cues like stars and the moon to help them navigate,” said Barton. “Whenever there's a lot of light pollution, that can disorient them and cause them to either veer off path or waste valuable energy while they're migrating.”
Since 2002, the Gateway Arch has turned its lights off during peak spring and fall migration seasons. Lights Out Heartland, a collaboration of organizations that work to reduce light pollution in the Midwest, hopes to expand upon those efforts by getting more businesses and residents to adopt bird-safe lighting practices, which can involve timers, motion detectors, dimmers, reduction of upward facing exterior lights and when possible, simply turning lights off.
It’s estimated that more than 25.8 million birds have crossed through St. Louis County on their journey south for the winter since August. Tens of millions more are expected to fly through the region before the end of October.
Longtime St. Louis birder Matt Schamberger said that while many migratory birds can be seen during the day, most of their vocalizations happen during the evenings.
“In fall, they're not doing as much of their songs or singing. Singing is about trying to proclaim territory and attract a mate, and so there's a lot less of that,” he said. “Instead, they're making what are often known as contact calls. During the nighttime flights, the birds are making a lot of calls to each other as they're flying, potentially to just to say, ‘Here I am. Where are you?’ if they can't see each other.”
For more on fall migration season, including tips for unique species to look out for and the best spots for bird watching in the region, listen to St. Louis on the Air on Apple Podcasts, Spotify, YouTube or click the play button below.
Related Events
What: Beginner Bird Walk
When: 8:30 a.m. Sept. 28
Where: The Robert & Martha Gaddy Bird Garden in Tower Grove Park, South Kingshighway and Magnolia Avenue, St. Louis, MO 63110
“St. Louis on the Air” brings you the stories of St. Louis and the people who live, work and create in our region. The show is produced by Miya Norfleet, Emily Woodbury, Danny Wicentowski, Elaine Cha and Alex Heuer. Darrious Varner is our production assistant. The audio engineer is Aaron Doerr.
