How excessive lighting affects bird migration

Millions of animals perish every year because of the disorientation and collisions caused by too much artificial light. The availability of food is impacted by changes in temperature, humidity, and rainfall patterns brought on by climate change.

How excessive lighting affects bird migration
Bird migration can be disrupted by artificial light. Photo by Chris Briggs / Unsplash

Migration is a natural and common phenomenon for many animal groups; however, in the case of birds, it is most common in species that live in more seasonal places where food availability favors moving during periods when ecological conditions become difficult for survival, which is why they migrate to regions where they can find more food, a better climate, and better living conditions.

This is a typical practice throughout the planet's northern and southern regions. Some tropical birds migrate as well, albeit to a lesser extent. This is a natural approach used by many bird species, but not all.

The goal is to raise public awareness of a beautiful act. It causes us to look about us and realize that these birds have come from a very long journey, that they have crossed boundaries, and that they have done a very important task. It also makes us consider the attitudes we can change and the activities we can take to lessen the influence of humans on the environment.

Cities are a significant source of light pollution, which has major and harmful consequences for their migration. Artificial light has been proven to alter numerous behaviors and disorient their course. Measures can be done, such as dimming building lights at least during the peak migration months of May and October.

Artificial light is increasing globally, at least two percent each year, and this has a huge impact on them because it creates disorientation when they fly at night, their internal clocks are misaligned, and they crash with buildings and other problems. Long-distance migrations are jeopardized.

New survival difficulties

Approximately 70% of northern birds migrate, with the other 80% following their paths at night and orienting themselves by moonlight and starlight. Artificial light sources completely disorient these birds' trajectories because their neurological system is built to use light as a type of direction. They are frequently drawn to artificial light, and they collide with structures, killing millions of species each year.

Because the organisms are not evolved to have light at night, light pollution affects resident birds' diurnal cycles and reproduction. Climate change is another factor influencing global movements, posing new survival concerns in some regions.

Climate change has a significant impact on these migratory routes because it alters the conditions of temperature, humidity, and rain cycles, which has an impact on the availability of food for birds, which is heavily reliant on insects. It is similar to a chain of related impacts that impose significant and novel barriers to organism survival and reproduction.

Although there is no official count of how many migratory birds enter and leave the country each year, there are initiatives such as the National Commission for the Knowledge and Use of Biodiversity's Citizen Science, in which a group of citizens photograph species and register them in a database to learn more about them.

Naturalist (, a worldwide citizen science network that has been running for less than a decade and covers 11 nations, accomplishes 50 million observations of nature, with photographs of plants, fungi, and animals. Specialists identify species to exchange knowledge and build a big, high-quality database for a wide range of applications, including nature protection, agriculture, forestry, tourism, education, culture, and health.