Hundreds of millions of birds die in collisions with building windows each year in the US

Each year hundreds of millions of birds die in the U.S. after colliding with windows. Skyscrapers are not the chief cause, but mostly mid-rise buildings. My guide in trying to understand why birds are more likely to collide in three and four-story buildings is Heidi Trudell. She’s an avian collision specialist who works with groups such as Washtenaw Safe Passage .