The Gateway Arch in St. Louis, Missouri, has turned off its exterior lights for the month of September as part of an ongoing effort to protect migratory birds. This measure aims to prevent the disorienting effects of artificial light on the millions of birds traveling along the Mississippi Flyway, one of North America's busiest avian migration routes.
The lights will be extinguished each evening to reduce the risk of birds veering off course or colliding with buildings. National Park Service data indicates that approximately 40% of the nation's migratory waterfowl depend on the Mississippi Flyway, and many navigate under the cover of darkness. The Arch's illumination has been identified as a significant hazard.
This initiative has been in place since 2002, with the Gateway Arch going dark annually in both May and September to support spring and autumn migrations. More than 300 bird species pass through the St. Louis area during these periods. The lights are expected to return to their normal schedule in October, after the peak of the autumn migration.
The Audubon Society offers additional recommendations for individuals to assist migratory birds. These include keeping cats indoors, reducing outdoor lighting, and making windows visible to birds by using decals or paint to disrupt the illusion of open sky or trees. Regular cleaning of bird feeders is also advised to prevent disease transmission among avian populations.
This effort comes as bird populations face significant threats. Last year, a record number of migrating birds died after colliding with buildings in New York City's skyline. A 2019 study by Cornell University estimated that approximately three billion birds have died in North America since 1970. The Audubon Society has warned that 389 North American bird species could become extinct within the next 50 years, a trend that could disrupt global ecosystems and impact agriculture and economies reliant on bird pollination and other services.