Migratory birds face a gauntlet of human-caused threats along their migration routes including hunting, building collisions and habitat loss at stopover sites.
Migratory birds face welfare challenges that are distributed across entire continental distances and involve multiple independent threat vectors. Birds shot during legal and illegal hunting face injury and death. Those that survive collisions with buildings or illuminated structures may do so with broken wings or internal injuries that cause prolonged suffering. The exhaustion of migration with inadequate stopover refuelling opportunities represents a form of physiological suffering driven by habitat degradation. Climate change is creating a mismatch between arrival times and food availability that means more birds fail to breed successfully, representing a form of population-level welfare failure.