Window collisions kill an estimated 600 million birds annually in North America alone, making collision prevention one of the most impactful individual wildlife welfare actions.
Window strikes cause acute welfare harm through traumatic brain injury, internal hemorrhage, and cervical fractures that kill birds or leave them severely injured. Birds that appear to fly away after a collision often die hours to days later from internal injuries. The scale of this mortality - billions of birds annually - makes window collision mitigation one of the highest-impact individual welfare actions available to homeowners. The solutions are available, effective, and increasingly affordable: external window films, screens, and properly spaced decals (5x10cm grid pattern) dramatically reduce bird collisions. The commonly seen single decal (e.g., owl silhouette) centered on a window is largely ineffective - the full grid pattern is required.