Light Pollution & Migratory Birds

• 17 May 2022

Each year, World Migratory Bird Day is celebrated on two days - on the second Saturday of May and October.

• The Days 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.
• Activities to mark the day were held globally under the theme 'Dim the Lights for Birds at Night'.

Light Pollution

• 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".
• 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.

Impacts of Light Pollution on Birds

• 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.

Conservation Value of Darkness

• According to the Convention on the Conservation of Migratory Species of Wild Animals (CMS), "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.

About CMS

• 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.