Wild Bird Window Strike Prevention

Window strikes kill an estimated one billion birds annually in the United States alone, making glass collision one of the most significant preventable sources of bird mortality.

Key Facts

Glass surfaces kill an estimated 599 million to 1 billion birds in the US each year through collision.
Birds cannot perceive glass as a barrier — they see reflections of sky and vegetation and fly toward them.
Most window strikes occur on low buildings and residential homes rather than skyscrapers, making household prevention highly impactful.
Decals, external screens, bird tape, and acid-etched or fritted glass all effectively reduce strike rates.
Placement of feeders within one metre of windows reduces strike fatality risk because birds lack velocity to injure themselves severely.

Welfare Considerations

Window strikes cause an enormous scale of suffering and death in wild bird populations that is largely invisible because birds that are injured or killed often fall and are removed by predators quickly. The welfare harm is acute — birds that survive strikes often suffer concussion, internal bleeding, and gradual death over hours. Given the scale of mortality and the availability of simple preventive measures, window strike prevention is one of the highest-impact actions available to individual householders for wild bird welfare.

What You Can Do

Apply external bird tape or collision deterrent decals to windows that reflect vegetation or sky.
Position feeders either within 1 metre or more than 10 metres from windows to reduce strike risk.
Use window screens or external netting on large glass surfaces that cause repeated strikes.
Report bird strikes and support research into collision rates and prevention effectiveness through citizen science programmes.