Window strikes injure and kill billions of wild birds annually, and even companion birds in outdoor aviaries or during indoor free-flight are at risk. Prevention measures protect birds in both contexts.
Window strike welfare harm occurs acutely at the moment of impact — traumatic brain injury, fractures, and internal hemorrhage cause immediate pain and often prolonged suffering before death. Birds that survive the initial strike may die over hours from internal injuries or remain concussed and vulnerable to predation. For companion birds during indoor free-flight, windows and glass doors are serious hazards that should be covered or marked to prevent collision. Installing bird-friendly glass treatments — frosted patterns, UV-reflective coatings, or external screens — dramatically reduces strike rates for both wild birds around buildings and companion birds in flight. Simple low-cost solutions including vertical tape strips at 10 cm spacing on external window surfaces are highly effective. Advocating for bird-friendly building design standards in new construction addresses the problem at scale.