Wild Bird Window Strike Welfare and Prevention

Building windows kill an estimated 600 million birds annually in the US alone. Simple prevention measures dramatically reduce this invisible welfare problem affecting wild bird populations.

Key Facts

Bird-window collisions cause an estimated 600 million to 1 billion bird deaths annually in the United States
Collisions occur because birds cannot perceive glass as a barrier and try to fly through reflected sky or vegetation
Low-reflectivity and high-reflectivity glass both cause collisions through different visual mechanisms
Fritting, dots, or lines on glass at 5cm spacing reduce collision risk by approximately 80% while maintaining views
UV-reflective glass visible to birds but not humans provides collision reduction without visible markings
External screens and netting provide effective protection by eliminating the glass surface entirely
Collision survivors often die hours later from internal injuries making visible survival misleading
Bird feeders placed within 90cm of windows or over 10 meters away reduce collision risk from approach angles

Welfare Considerations

Window strikes cause acute traumatic injury and death to hundreds of millions of individual birds annually. Birds that appear stunned and recover visible from their experience have sustained head trauma that causes significant pain and may result in delayed mortality. The welfare response to this massive preventable harm is straightforward: prevention measures are available, affordable, and effective. Individuals, businesses, and urban planners all have roles in reducing collision mortality through simple interventions including window markers, netting, and bird-safe glass specifications in new construction. This represents one of the most tractable large-scale wildlife welfare improvements available.

What You Can Do

Apply collision deterrent products including dot or line patterns to problem windows at your home or office
Place bird feeders either within 90cm of glass or more than 10 meters away to reduce collision risk
Use external screens or netting on windows near bird feeding stations
Specify bird-safe glass in any new construction or renovation projects
Report collision incidents to the Fatal Light Awareness Program (FLAP) for research and advocacy purposes
Advocate for bird-safe building design standards in local planning and building codes