Nearly 1000 migratory birds died after flying into a Chicago building on October 5, 2023. The collision was caused by a combination of factors, such as a storm, bright lights, and reflective glass.
Nearly 1000 migratory birds die after colliding with a single building
On the night of October 5, 2023, a record number of migratory birds died after flying into a Chicago building. According to the Field Museum, which monitors bird collisions in the city, nearly 1000 birds were found dead or injured around the McCormick Place Lakeside Center, the largest convention center in North America. This is the highest daily toll ever recorded at the site, which is known as a notorious hotspot for bird strikes.
The majority of the victims were warblers, small and colorful songbirds that migrate long distances between North and South America. Among them were species such as Blackpoll Warbler, Magnolia Warbler, Chestnut-sided Warbler, and American Redstart. Some of them had traveled thousands of miles from their breeding grounds in Canada and Alaska, only to meet their end in Chicago.
What caused the mass collision?
The mass collision was the result of a combination of factors that created a perfect storm for the birds. According to BirdCast, a project by Cornell University that tracks bird migration, there was an unusually large number of birds in flight above Cook County, where Chicago is located, on the night of October 5. The project estimated that nearly 1.5 million birds were in the air, taking advantage of favorable winds and low temperatures.
However, as a storm passed over the city, many of the birds were forced to descend to lower altitudes, where they faced increased danger from artificial lights and glass windows. The lights can disorient and attract the birds, while the windows can reflect the sky and vegetation, creating an illusion of open space. The birds then collide with the glass at high speed, causing fatal injuries or stunning them.
The McCormick Place Lakeside Center was particularly hazardous for the birds, as it had its lights on for an ongoing event. The building is also located near Lake Michigan, which is a major flyway for migratory birds. The combination of bright lights and reflective glass proved deadly for hundreds of birds that crashed into the building.
How can bird collisions be prevented?
Bird collisions are a serious threat to bird populations, as they kill hundreds of millions of birds every year in the United States alone. Some cities, such as Chicago, have taken steps to reduce this threat by implementing programs such as Lights Out, which encourages buildings to turn off or dim their lights during peak migration seasons. The program has been shown to reduce bird collisions by up to 80%.
Other measures that can help prevent bird collisions include:
- Using bird-friendly glass that has patterns or coatings that make it visible to birds
- Installing screens or netting over windows to create a barrier
- Placing decals or stickers on windows to break up the reflection
- Moving indoor plants away from windows to avoid attracting birds
- Providing bird feeders and water sources away from windows
- Educating the public and building owners about the issue and how to help
How can people help injured or dead birds?
If people find injured or dead birds near buildings, they can help by:
- Reporting the incident to local authorities or organizations that monitor bird collisions
- Taking the injured bird to a wildlife rehabilitator or veterinarian
- Placing the dead bird in a paper bag and labeling it with the date, location, and species (if known)
- Donating the dead bird to a museum or research institution for scientific purposes
By taking these actions, people can contribute to saving lives and advancing knowledge about migratory birds.