Migrating Birds Dying in Huge Numbers From Flying Into Glass Buildings

The glimmering skyline of Philadelphia is a little dimmer these days, but it’s not a blackout. Migrating birds are crashing into tall buildings and dying in huge numbers. When night falls, office towers and apartment buildings dim their lights to help birds stay on course. Birds use the stars to navigate. When flying over big cities, bright lights can disorient them. Sadly, researchers estimate that as many as 1 billion birds in the US alone are killed each year after hitting buildings.