Barnacle geese breeding in Svalbard face emerging welfare challenges as climate change creates phenological mismatches between goose breeding timing and the availability of vegetation needed to feed growing goslings.
Barnacle goose welfare illustrates the phenological mismatch problem that climate change is creating for many migratory birds. The precise timing of migration and breeding has evolved to synchronize gosling hatching with peak vegetation quality in breeding grounds, providing optimal nutrition during the most energetically demanding growth period. When vegetation peaks earlier than gosling hatching due to differential warming rates, goslings grow more slowly and have lower survival rates than in well-matched years. Individual goslings experiencing nutritional shortfall during growth face both short-term welfare costs from restricted nutrition and long-term consequences for body condition that affect lifetime fitness. Monitoring these mismatches provides early warning of welfare impacts that policy cannot address directly but that motivate climate action.