Climate change is disrupting bird migration patterns and timing, causing welfare problems from mismatches between breeding and food availability, and altered migration routes.
Climate change bird migration welfare operates at both individual and population levels. Individual chicks that hatch after peak caterpillar abundance face nutritional stress that reduces survival. Migrants that arrive before their food sources are available face starvation during a critical energy-intensive period. These individual welfare costs accumulate across entire populations experiencing the same timing mismatch. The welfare implications of range contractions are severe for species unable to shift their ranges sufficiently - declining populations face higher individual stress from resource competition in shrinking habitat.