Polar bears are the most ice-dependent of all bear species and face an existential welfare crisis as Arctic sea ice diminishes, forcing longer fasting periods, reduced reproductive success, and declining body condition across populations.
Polar bears experiencing extended fasting are not merely uncomfortable — they are in a state of increasing metabolic crisis that affects cognition, movement capacity, and reproductive function. Pregnant females who cannot accumulate sufficient fat reserves before denning may resorb foetuses or produce cubs too small to survive. Cubs born to nutritionally stressed mothers have lower survival rates. The experience of sustained hunger over weeks and months, combined with the metabolic costs of thermoregulation in a cooling body, represents a profound welfare harm inflicted on entire populations by climate change. Individual bears drowning in open water, or killed in conflict after entering communities, are acute welfare casualties of the same systemic cause.