Animals at Risk

Light pollution also harms wildlife. “Animals depend on patterns of light and dark,” says Travis Longcore. He is an ecologist with the Urban Wildlands Group. According to Longcore, lighting up the night changes the way animals behave.

Light pollution has the worst effect on birds. Many birds migrate at night and use the stars like street signs to find their way. Bright lights sometimes confuse birds in flight. Lights from buildings and towers attract the birds. The birds veer off course, and sometimes whole flocks of birds crash.

Millions of migratory birds crash into buildings each year and die. The birds in this photo were all killed in Toronto, Canada, while migrating one year.