Scientists estimate up to 1 billion birds meet untimely demise thanks to illuminated buildings. Light pollution of the airspace is a relatively recent but growing threat to nocturnally migrating birds. Minneapolis ranks among the top 10 cities posing the greatest dangers to birds in this most recent study, authored by researchers at Cornell University, along with cities like Los Angeles, Chicago, Houston and St. Louis.
You may wonder, how else do birds die? This 2003 chart from the Sibley Guide to Birds suggests that the life of a bird has many hazards:
Windows have long been a source of peril for the modern migratory bird per this 2003 chart of bird mortality.
Numerous buildings in Minnesota participate in the Audubon Society’s Lights Out program each year. Through this program, buildings commit to turning off their lights during spring and fall migration periods between midnight and dawn; participating buildings include the Minnesota Capitol complex, as well as many notable buildings in Minneapolis, the suburbs, Rochester and Duluth. The spring program period goes from March 15 to May 31. This program also conserves energy. Find out more at the Minnesota Audubon Society, and visit BirdCast for daily maps of migration patterns.