Puffins nest in burrows excavated in soft soil on cliff tops and islands, and their welfare depends on suitable soil conditions, vegetation cover and freedom from burrowing predator disturbance.
Puffin chicks (pufflings) confined to burrows are entirely dependent on parental feeding visits. Puffling starvation occurs when parents cannot deliver sufficient sandeels due to overfishing or climate-driven fish movement. Burrow collapse buries pufflings alive. Predator incursions cause acute fear and mortality throughout colonies. Individual puffin welfare is determined by the sum of soil quality, food availability and predator management.