Billions of birds undertake seasonal migrations each year, facing an increasing gauntlet of human-created hazards including building collisions, light pollution, pesticide exposure, and habitat loss at critical stopover sites.
Migratory bird welfare involves the compounding welfare effects of multiple human-created hazards concentrated during the most physiologically demanding period of these animals' lives. Migration is already an extreme undertaking — birds must accumulate enormous fat reserves, restructure their organs for sustained flight, and navigate thousands of kilometers with precision. Adding glass collision hazards, light disorientation, pesticide-impaired navigation, and depleted stopover resources multiplies the difficulty and mortality rate. Individual birds that survive all these hazards may still arrive at breeding grounds depleted, reducing their reproductive success and long-term survival. Addressing migratory bird welfare requires coordinated international action because the threats span the entire migration route from wintering to breeding grounds.