Light Pollution and Wildlife

At night, many cities shine brightly with the light of streetlamps, buildings, and signs. This light makes it easier for people to move around safely after dark, and few of us could imagine life without it. However, scientists warn that too much artificial light at night, a problem known as "light pollution," can be very harmful to wild animals. For millions of years, living things have depended on the natural cycle of day and night, and bright city lights can （ 1 ） this cycle.

Sea turtles are one well-known example. When baby turtles hatch on a beach, they find their way to the ocean by crawling toward the brightest light, which in nature is the open sky above the sea. （ 2 ）, in places with many hotels and streetlights, the land behind the beach is now brighter than the ocean. As a result, the young turtles often crawl in the wrong direction, away from the water, and many of them die before they ever reach the sea.

Birds and insects are affected too. Many birds travel at night and use the stars to find their way, but city lights can confuse them and cause them to crash into tall buildings. Insects such as moths gather around lamps instead of feeding or laying eggs. To help, some towns now use lights that shine only downward and switch off lights that are not needed. （ 3 ） these simple changes, both people and wildlife can share the night more safely. Such changes cost very little money, yet they can make a real difference to the animals that live nearby.