Window collisions are by far one of the most devastating killers of birds worldwide. It’s estimated that as many as one billion birds are killed annually in the U.S. this way. What makes window collisions so terrifying is not just how frequent they are, but how gruesome they can be. Those that survive are usually stunned and easily picked off by feral cats, rats, dogs, natural predators, and street sweepers. The few birds that somehow manage to survive often sustain head injuries that will slowly kill them later on in life.
Birds collide with glass because they cannot see it. Birds will either see through the glass, or the reflections off the glass. Reflective glass is the most dangerous type of glass for birds. If reflective glass is facing green space, birds will believe there is more suitable habitat for them on the other side of the glass and will collide with it.
The tragedy of window collisions is that they are the most avoidable. While issues like climate change call for many large changes to society as a whole, all that window collisions require to be stopped are for people to close their blinds more often, turn out the lights when they are gone, use glass that is bird-visible and non- reflective, and/or place decals on their windows.