Bird Window Collisions: Scale and Solutions

Window and building glass collisions kill an estimated 600 million birds in the US alone each year, making it one of the leading causes of bird mortality in the built environment.

Key Facts

Estimates suggest 600 million to 1 billion birds die from window strikes in the US annually
Birds cannot perceive glass as a barrier, especially when vegetation is reflected in it
Collisions cause immediate death or severe injury including brain trauma, broken wings, and internal haemorrhage
Bird-safe glass, window markers, and external nets can reduce collisions by up to 90%
Most collisions occur at residential buildings rather than skyscrapers, making individual action highly impactful

Welfare Considerations

A window strike causes acute trauma — many birds die immediately from brain injury or internal bleeding, while survivors may be left stunned and vulnerable to predation or die hours later from their injuries. The scale of this problem is enormous and almost entirely unaddressed in building regulations. Because most strikes occur at homes, individual action is highly impactful. Simple, inexpensive solutions like placing decals on the outside of glass at close intervals can dramatically reduce strike rates.

What You Can Do

Apply bird-safe window decals or tape in a grid pattern at 5cm intervals on problem windows
Install external screens or nets on large glass surfaces near bird habitat
Place feeders and plants either very close to or far from windows to reduce risky trajectories
Report window strike victims to local wildlife rehabilitation and bird monitoring schemes
Advocate for bird-safe building standards in local planning requirements