Up to a billion birds die annually from colliding with glass windows and buildings in North America alone. This entirely preventable welfare crisis has simple, proven solutions that save lives at low cost.
Bird-window collisions cause acute physical trauma — broken necks, concussion, internal injuries — and death that is rarely instantaneous. Birds that survive the initial impact often die within hours or days from delayed injury, predation in their stunned state, or secondary infection. The suffering of collision victims is real and significant. Yet window collisions are almost entirely preventable with readily available and inexpensive interventions. The scale of the problem — comparable to or exceeding the mortality caused by domestic cats, wind turbines, or power lines — makes it one of the highest-impact welfare improvements available to individual households and building managers. Most effective solutions require only a one-time application and impose minimal visual disruption on occupants.