Wildlife

Wild Bird Collision with Glass Buildings and Mitigation

Collision with glass buildings and windows is a major cause of bird mortality globally, but effective mitigation exists.

Key Facts

An estimated 100 million-1 billion birds are killed annually by glass collisions in North America alone
Birds cannot perceive glass as a solid surface and attempt to fly through it
Fritted glass, UV-reflective patterns and exterior vertical cables prevent most collisions
The most dangerous buildings are those with pass-through views of sky or vegetation
Lighting reduction in buildings during migration season significantly reduces night collisions

Welfare Considerations

Glass collisions cause acute trauma - concussion, internal haemorrhage and broken bones. Many birds die immediately; survivors may suffer for hours. Simple and low-cost interventions applied to the most dangerous buildings would prevent millions of deaths annually. New buildings can be designed bird-safe from the outset.

What You Can Do

Apply window collision prevention patterns to home windows in high-risk areas
Advocate for bird-safe building design standards in urban planning
Support campaigns for mandatory bird-safe design in new commercial buildings
Report glass collision hotspots to local wildlife groups for monitoring