Polar bears depend on sea ice as a platform for seal hunting — as Arctic ice retreats, individual bears face longer fasting periods, nutritional stress, and increased conflict with humans.
Polar bears fasting through extended ice-free seasons experience progressive physiological deterioration — burning muscle mass after fat reserves deplete, compromising immune function, and in extreme cases starving before ice forms. Cubs born to nutritionally-stressed mothers are smaller and less likely to survive. The welfare consequences of sea ice loss are measurable in individual bear body condition, reproductive success, and mortality rates. This is climate change made visible in the suffering of individual large mammals.