ST. LOUIS — The Gateway Arch will not be lit up at night throughout the month of May. It's a tradition that goes back decades at the national park.
The National Park Service has been turning off the Arch's exterior lights in May and September to avoid disorienting birds making their way through the Mississippi Flyway since 2002.
The Mississippi Flyway is one of four major routes for bird migration in North America, according to the American Bird Conservancy. Many birds who spend their winters in South and Central America use the route to travel back northward along the Gulf of Mexico and the Mississippi, Missouri and Ohio rivers.
According to the Three Rivers Park District, 325 bird species and roughly 40% of North America's shorebirds and waterfowl use the flyway.
In December, the Arch began using an upgraded LED lighting system that is brighter with reduced energy usage and can be "dialed in more exactly with less spillover and light pollution" to reduce the impact on wildlife migration and behavior year-round, Gateway Arch National Park Superintendent Jeremy Sweat told 5 On Your Side.
However, the new lighting system can still pose risks for birds during peak migration.
"Turning the lights off completely is the best way to help ensure migrating birds’ safe passage during these high-intensity migration months," Program Manager of Museum Services and Interpretation at Gateway Arch National Park Pam Sanfilippo said in a statement.
The Arch's exterior lights will be turned back on the evening of June 1.
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