Emperor penguins breed on sea ice during the Antarctic winter, making them uniquely vulnerable to sea ice decline from climate change.
Emperor penguin chicks falling through weakened or insufficient sea ice before they have waterproofed feathers drown in Antarctic waters. Mass chick mortality events from sea ice breakup before fledging, like those seen in 2022-2023, kill tens of thousands of individuals simultaneously. Adult birds deprived of adequate breeding ice cannot complete reproduction, representing welfare failure for thousands of pairs each year. The inability of emperors to adapt their breeding timing or location rapidly in response to ice changes means climate warming directly translates to population-scale welfare harms.