Most birds migrate at night. They have been doing this for eons, as a night sky typically means calmer air space and fewer predators. Nocturnally migrating birds include ducks and geese, plovers and sandpipers, and songbirds of all kinds. These birds may travel thousands of miles between their breeding and non-breeding grounds.
However, the night sky is under threat. Artificial light is increasing globally by at least two percent a year, presenting a problem for birds. Light pollution from homes, businesses, and other infrastructure attracts and disorients migrating birds, making them more likely to land in dangerous areas where they are more vulnerable to collisions and predation. Artificial light also impacts birds in the breeding and winter seasons, disrupting feeding and other vital behaviors.
In 2022, the impact of light pollution is the focus of World Migratory Bird Day, an annual global campaign that celebrates the migration of birds across countries and continents. Throughout the year we will spread the message to “dim the lights for birds at night” and highlight the steps that individuals, communities, and governments can take to reduce the impact of light pollution on our shared birds.