Building glass kills up to a billion birds annually in the US — bird-safe design solutions exist and work.
Window collisions cause traumatic brain injuries, broken necks, and internal bleeding that kill birds outright or cause delayed deaths hours later. The problem is concentrated at large glass buildings during migration — billions of birds move through North America in spring and fall and cannot perceive glass as a barrier. Solutions exist: UV-reflective patterns that birds perceive but humans do not, external screens, offset glass panels, and internal patterns applied to glass all dramatically reduce strikes. Building codes that require bird-safe glass in new construction represent the most scalable solution.