The Atlantic puffin (Fratercula arctica) has declined by 30% in the UK since 1986, with Scottish colonies experiencing particularly severe breeding failure in warm years when sandeels — their primary prey — move to deeper, cooler water beyond puffin diving range.
Puffin chicks starving in their burrows experience prolonged death: adults that cannot find sandeels return to burrows with alternative prey items that may be nutritionally inadequate or too large for chicks to swallow. Chick starvation over several days is a welfare harm repeated across thousands of burrows in failure years. Adults that invest heavily in breeding attempts that fail suffer energetic depletion. The systemic nature of climate-driven failure means conventional conservation interventions — predator control, habitat management — cannot address the root cause. Welfare monitoring at puffin colonies tracks chick growth rates, diet composition, and breeding success as indicators of prey availability.