Wild Bird Window Collisions: Prevention and Solutions

Window strikes kill up to a billion birds annually in North America alone. Simple, effective prevention measures can dramatically reduce this preventable mortality.

Key Facts

An estimated 600 million to 1 billion birds die from window strikes in the US each year
Birds cannot perceive glass as a barrier and fly toward reflected sky, vegetation, or light
Large, clear windows pose the greatest risk, particularly those facing gardens or containing plants
Approximately half of birds that strike windows die immediately; many more die from injuries over hours or days
UV-reflective patterns visible to birds but not humans represent the most aesthetically acceptable solution
External measures applied to the glass surface are significantly more effective than internal options

Welfare Considerations

Window strikes cause traumatic injury with significant suffering. Birds that do not die immediately are often found stunned and disoriented, experiencing concussion and internal injuries before dying hours later. The scale of this mortality — billions of birds annually — represents one of the most significant human-caused sources of bird suffering, and it is almost entirely preventable with easily available solutions. Every building with bird-safe windows prevents real, ongoing suffering.

What You Can Do

Apply external bird-safe window films, tapes, or decals to glass that poses collision risk
Use the rule of two: external visual markers spaced no more than 5cm horizontally and 10cm vertically
Install screens, awnings, or external shutters on problematic windows
Move bird feeders to within 1 meter of windows (so birds cannot build fatal speed) or over 10 meters away
Advocate for bird-safe building design in new construction and renovation projects
If you find a stunned bird, place it in a ventilated box in a quiet, dark space and contact a wildlife rehabilitator