Lights out for the Mississippi Flyway

Twice a year, something extraordinary passes over Kirkwood in the dark. Millions of birds — warblers, thrushes, tanagers, sparrows — migrate along the Mississippi Flyway, one of North America’s great aerial highways, which follows the rivers right past St. Louis.

Most of them fly at night, and most of them navigate, in part, by the stars. Which is exactly the problem.

How our light hurts them

Artificial light at night disorients migrating birds. It pulls them off course toward brightly lit areas, where they circle lit buildings until they’re exhausted — or collide with glass they never see. Across the U.S., building collisions kill an estimated hundreds of millions of birds every year, and a 2024 study suggests the real toll may top a billion.

When one major Chicago building turned off half its lights on migration nights, collisions dropped several-fold. Darkness, it turns out, is the cheapest bird-safety measure there is.

St. Louis already does this

You can see the fix downtown. Each spring and fall migration, the National Park Service turns off the Gateway Arch’s exterior lighting to protect night-flying birds. It’s a small act with a big reach — and your home can do the same.

What you can do — it takes five minutes

• During migration (roughly April–May and September–October, peaking in May and September), turn off non-essential outdoor lights from 11pm to dawn.
• Put necessary lights on motion sensors and shield them to point down.
• Close the blinds on bright upstairs windows at night.
• Swap blue-white bulbs for warm ones — better for birds and for you.

Watch the live BirdCast forecast for St. Louis County to catch the big nights, and join the regional Lights Out Heartland campaign.