Nocturnal animals have evolved for darkness and suffer welfare harms from light pollution that disrupts their navigation, foraging, reproduction, and predator avoidance. Understanding this threat guides effective responses.
Light pollution causes welfare harms to nocturnal species that are largely invisible to most humans because they occur in darkness. Turtle hatchlings that crawl away from the sea, migratory birds that exhaust themselves circling lit buildings, and insects drawn to fatal illumination all experience preventable welfare harms. Unlike most environmental threats, light pollution can be reduced locally and rapidly through behavioral and technical changes that have immediate wildlife benefits.