St. Louis Arch goes dark this month as billions of birds migrate along Mississippi River

Now that it's September, the most iconic landmark in St. Louis will once again go dark.

During our local peak fall bird migration in May and September, the exterior lights of the Gateway Arch get turned off at night to help protect billions of birds traveling along the Mississippi Flyway. 

According to the St. Louis Audubon Society, 325 different species of birds, including sixty percent of North American songbirds and forty percent of waterfowl, use the route along the Mississippi River every year.

The National Park Service has turned off the arch's lights during peak migrations since 2002.

Scientists say that 80 percent of birds migrate at night, and bright artificial lights disorient them. Karen Trevino, director of the National Park Service’s Natural Sounds and Night Skies Program, says outdoor light at night can be particularly harmful for migrating birds. “Each year light pollution causes disorientation, collisions with buildings and windows, and interferes with their ability to endure long distance migrations.”

It's estimated that 3.5 billion birds are killed each year by flying into windows and buildings.

"Lights Out" campaigns take place in many other major cities across the country. 

Using the Birdcast website, you can see nightly estimates of the number and variety of species of birds that are currently moving through our area from as far away as the Arctic and central Canada, down through the central United States to the Gulf of Mexico and South America.


(AP Photo Jeff Roberson) (Map: U.S. Fish and Wildlife)