Two different times a year it is estimated that five million birds of 250 differing species fly through the city of Chicago. The birds are migrating and can travel thousands of miles each year. When the birds pass through large cities, they are attracted to reflections and especially light. Tens of thousands of these birds are either severely injured or die each year from collisions with buildings.

The song sparrow is a bird that is a common casualty in Chicago. The song sparrow are nocturnal, which means that they fly at night. When they fly beside buildings, the lights in and on the buildings can confuse the birds. Sometimes they crash into the building, and other times, exterior lights disorient the birds and cause them to circle the building continuously until they are exhausted and have to land. According to Rebekah Creshkoff, “birds can fly into glass windows as they fly toward a reflection or even a planter inside the building.”  Rebekah is part of the New York City Audubon Society, a group that works to get lights turned off in buildings at night, and initiates and supports legislation to protect wild birds. Rebekah goes on to say, “The problem is easy to overlook because you don’t see it in the aggregate. A person will see one dead bird here, one bird there. But it is still a huge problem.”

In Chicago, the city is backing the effort.

The lights on the roof of the Sears Tower have been turned off during the two appropriate times of year. The crown of lights on the top of the John Hancock Center have been dark as well.  And such popular architectural icons as the Wrigley Building and the gothic Tribune Tower have dimmed their lights, too.

The goal is to attract less attention at night. Migrating birds are attracted by the lights of buildings, and many times confuse a light bulb with the stars that navigate them. And often times, the birds crash into the windows. The light that helps people in the dark, is the same light that can kill birds.

”We think several hundred thousand birds a year die from striking buildings in Chicago,” said Suzanne Malek, who is the deputy commissioner of natural resources. The Lights Out program asks building owners to turn out their ornamental lights during migration season which runs from April to May and September to October.