Artificial sky brightness from outdoor lighting interferes with natural nighttime behaviors of critical species. Around the world, ecosystems are being adversely impacted by light pollution— reducing light pollution is key to protecting wildlife.
Insects
One of the most concerning species declines is the staggering loss of insects and pollinators. While many environmental factors contribute to this, light pollution is shown to be a major player. About 50% of insect species are nocturnal, so artificial light severely impacts their life cycles. The unnaturally bright environment disrupts bioluminescent communication, light-based navigation, and where insects lay their eggs. Insect diversity is critically important for vital environmental functions— by losing insect diversity, entire ecosystems are at risk.Â
Sea turtles
As the world’s beaches become more developed, the increased outdoor lighting is shown to endanger successful sea turtle hatching. Born on the sand, sea turtles must trek from the land into the ocean, but when there are bright lights lining the beaches some turtles have been observed to walk towards these lights instead of the waves. By interrupting the hatching process, light pollution is further threatening sea turtle populations.Â
Cougars
A 2023 study found that cougars in light-polluted areas avoid habitats with excessive artificial lighting, leading to habitat fragmentation and changes in hunting behaviors. Due to the species’ individualistic habits, these shifts could interfere with food sourcing and mating. As top predators, cougars are an important piece of the food chain. Damage to cougar populations affects all species that rely on them for ecosystem equilibrium.Â
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Authors
Ellen runs campaigns to protect America’s beautiful places, from local beachfronts to remote mountain peaks. She sits on the Steering Committee of the Arctic Defense Campaign and co-coordinates the Climate Forests Campaign. Ellen previously worked as the organizing director for Environment America’s Climate Defenders campaign and managed grassroots campaign offices across the country. Ellen lives in Denver, where she likes to hike in Colorado’s mountains.
