Birds

Window Strike Welfare: Billions of Birds Die on Glass

Window collisions kill an estimated 600 million to 1 billion birds in the US annually, making glass one of the leading anthropogenic bird killers.

Key Facts

Glass collisions are second only to cats as the leading human-caused bird mortality in North America
Birds cannot perceive glass as a barrier and fly into reflections of sky and vegetation
Daytime strikes kill year-round; migratory birds are especially vulnerable at night
Simple window treatments can reduce collisions by 50-90%
The American Bird Conservancy has developed collision-reduction standards for buildings

Welfare Considerations

Window-struck birds suffer immediate trauma including internal hemorrhage, organ damage, and skull fracture. Those that appear dazed and fly away often die later from internal injuries. Millions suffer and die each year in ways that are almost entirely preventable with available technology. New building standards can prevent this at minimal cost.

What You Can Do

Apply ABC BirdTape or Acopian BirdSavers to your windows
Move bird feeders within 3 feet of windows to reduce strike speed
Turn off unnecessary lights at night during migration season
Advocate for bird-safe building standards in your city
Report building strikes to the Fatal Light Awareness Program (FLAP) database