Puffins are declining in several British breeding colonies as climate change shifts fish distributions away from traditional feeding areas, reducing chick survival and adult condition.
Puffin chick welfare is directly determined by sand eel availability within the parents' foraging range of the breeding colony. When sand eels are scarce or have shifted beyond practical foraging distance, chicks receive insufficient food and die of starvation in their burrows. Parents that continue to make unsuccessful foraging trips experience energetic depletion. The welfare of adult puffins is further affected by plastic ingestion - puffins mistake plastic fragments for prey, reducing feeding efficiency and potentially causing gastrointestinal damage. The climate-driven northward shift in sand eel distribution is not reversible at the colony level - puffins cannot simply relocate to follow prey without the multigenerational site-fidelity mechanism that established current colonies.