Chinstrap penguins are declining rapidly in some Antarctic Peninsula areas as krill populations are affected by climate change and commercial fishing.
Chinstrap chicks in colonies with insufficient krill provision die slowly from starvation as adults make progressively longer foraging trips with insufficient returns. Thin adults in poor body condition from inadequate krill access are more vulnerable to predation by leopard seals during foraging trips. Cold water exposure during extended swimming after failed foraging represents thermal stress in already nutritionally compromised birds. Population crashes from krill decline are reflected in the welfare of thousands of individual birds failing to raise chicks successfully across multiple consecutive seasons.