Billions of birds migrate annually, facing an gauntlet of human-caused hazards. Protecting migratory birds is both a conservation and animal welfare imperative.
Migratory bird welfare operates at enormous scale — billions of individual journeys, each involving energetic stress, navigational challenges, and exposure to multiple human-caused hazards. Building collision casualties involve birds striking glass at high speed — not all die immediately, and injured survivors face further suffering or predation. Tower collisions typically cause death from impact. Cat predation causes acute suffering in captured individuals that may take minutes to die even from apparently minor injuries. The cumulative welfare burden on migratory populations is enormous, and the aggregate suffering caused by window collisions alone — perhaps the most preventable cause — represents a welfare cost that simple building modifications could substantially reduce.