World Migratory Bird Day: Light pollution or lit skies threaten birds globally

Representational photo/istock

On the eve of the World Migratory Bird Day 2022, light pollution and its impact on migratory birds is a focus with a global campaign that aims to raise awareness about migratory birds and the need for international cooperation to conserve them.

Activities to mark the day will be held globally under the theme 'Dim the Lights for Birds at Night'. World Migratory Bird Day is celebrated on two days. Traditionally observed on the second Saturday of May and October, the two celebrations of World Migratory Bird Day are a way to reflect the cyclical nature of bird migration as well as the fact that there are varying peak migration periods in the northern and southern hemispheres.

Light pollution is increasing around the globe. More than 80 per cent of the world's population is currently estimated to live under a "lit sky", a figure closer to 99 per cent in Europe and North America.

The amount of artificial light on the Earth's surface is increasing by at least two per cent each year and could be much greater, a release said.

Amy Fraenkel, executive secretary of the Convention on the Conservation of Migratory Species of Wild Animals (CMS) said: "Natural darkness has a conservation value in the same way as clean water, air, and soil. A key goal of World Migratory Bird Day 2022 is to raise awareness of the issue of light pollution and its negative impacts on migratory birds. Solutions are readily available, and we hope to encourage key decision-makers to adopt measures to address light pollution."

The Convention on Migratory Species (CMS) is an environmental treaty of the United Nations and provides a global platform for the conservation and sustainable use of migratory animals and their habitats.

Light pollution is a significant and growing threat to wildlife including many species of migratory birds. Every year, light pollution contributes to the death of millions of birds. It alters the natural patterns of light and dark in eco-systems. It can change birds' migration patterns, foraging behaviours, and vocal communication.

Attracted by artificial light at night, particularly when there is low cloud, fog, rain or when flying at lower altitudes, migrating birds become dis-orientated and may end up circling in illuminated areas. Depleted energy reserves put them at risk of exhaustion, predation, and fatal collision with buildings.

Jacques Trouvilliez, executive secretary of the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) said: "An enormous diversity of birds, active at night, experience the impacts of light pollution. Many nocturnally migrating birds such as ducks, geese, plovers, sand pipers and songbirds are affected by light pollution causing disorientation and collisions with fatal consequences. Seabirds such as petrels and shearwaters are attracted by artificial lights on land and become prey for rats and cats."

Guidelines on light pollution covering marine turtles, seabirds, and migratory shorebirds were endorsed by the CMS Parties in 2020. The guidelines set forth six principles of best lighting practices and call for Environmental Impact Assessments for relevant projects that could result in light pollution. These should consider the main sources of light pollution at a certain site, the likely wild species that could be impacted, and facts about proximity to important habitats and migratory pathways.

Numerous governments, cities, companies, and communities around the world are already taking steps to address light pollution.

Susan Bonfield, Director, Environment for the Americas, said: "World Migratory Bird Day is a call to action for international migratory bird conservation. As migratory birds' journey across borders, inspiring and connecting people along the way, it is our aim to use the two days in 2022 to raise awareness of the threat of light pollution and the importance of dark skies to bird migrations."