Wild Migratory Birds and Light Pollution

Artificial light at night disrupts the navigation, foraging, and breeding of billions of migratory birds, contributing to population declines and causing direct mortality through building collisions.

Key Facts

Over one billion birds die annually from building collisions in North America
Migratory birds navigate by stars — artificial light causes disorientation
Light-attracted birds circle lit structures until exhausted, then collide
Phenological mismatches from light-altered timing affect breeding success
Turning off lights during peak migration seasons reduces collisions by up to 80%

Welfare Considerations

Individual birds that collide with glass buildings or become disoriented around lit towers experience acute trauma — broken bones, internal hemorrhage, and spinal injury. Many do not die instantly. The welfare scale of light pollution mortality is vast: a single lit skyscraper during spring migration can kill hundreds of birds in a single night. Unlike many environmental threats, light pollution has immediate, tractable solutions that building owners can implement at minimal cost.

What You Can Do

Turn off non-essential indoor lights from midnight to dawn during spring and fall migration
Install bird-safe glass or UV-reflective patterns on large windows
Advocate for Lights Out programs in your city
Support Bird-Safe Building Certification standards for new construction
Participate in bird monitoring programs during migration to document collision mortality