Millions of birds fly over Minnesotans' heads every spring and fall, many along the Mississippi Flyway - a migratory corridor for 40 percent of North America's waterfowl and shorebirds.
But the increasing light pollution from human development in these areas, including the Twin Cities, is making the journey more perilous.
New research from the Cornell Lab of Ornithology has ranked Minneapolis as one of the most dangerous cities for migrating birds.
The reason? All of the lighting, including at night, can disorient traveling birds, causing them to crash into buildings. Cornell says an estimated 600 million birds die every year in the U.S. from building collisions.
Minneapolis is not the worst offender, according to Cornell's rankings. The city was rated sixth most dangerous for spring migration, and seventh most dangerous for fall migration.
Chicago, Houston and Dallas were considered the most dangerous in both seasons.
This was already a heated topic years ago during the construction of U.S. Bank Stadium as its large, clear panels and location near the Mississippi River earned it the label of "death trap" for migrating birds.
But it's not just skyscrapers and downtown buildings that pose a risk.
Study lead author Kyle Horton, a Rose Postdoctoral Fellow at the Cornell Lab, said about 250,000 bids die every year colliding with home windows.
"If you don’t need lights on, turn them off," he said in the release. "It's a large-scale issue, but acting even at the very local level to reduce lighting can make a difference."