Birds colliding with glass windows and buildings kill an estimated 600 million birds annually in the US alone, making window strikes one of the most significant human-caused bird mortality sources.
Birds that survive window strikes often experience concussions, internal hemorrhaging, and disorientation. Many die within hours from internal injuries that are not immediately apparent. Struck birds placed in quiet, dark boxes and given time to recover can survive if injuries are not severe. The welfare harm is amplified by scale - the cumulative death toll makes window strikes among the most impactful welfare issues for wild birds, and one where individual action can make a measurable difference.