Each spring, birds take to the skies, migrating across North America from their wintering grounds in Central and South America to reach their breeding destinations. But for too many, the journey ends in tragedy. Over one billion birds die each year in the U.S. alone from collisions with glass. Disorienting nighttime lighting and untreated windows pose serious threats to these remarkable travelers. Now is the time to act for birds. Dim or turn off non-essential outdoor lights from 11 p.m. to 6 a.