Brown bears entering hyperphagia before hibernation must consume 20,000 calories daily, and climate-driven food availability changes are creating nutritional stress that affects individual welfare and reproductive success.
Brown bear hyperphagia welfare is determined by the availability of sufficient caloric resources during the critical pre-denning period. Bears that enter winter dens with inadequate fat reserves face physiological stress during hibernation, reduced reproductive success, and in severe cases may emerge from dens in poor condition that limits early spring foraging. The climate-driven loss of key hyperphagia foods — whitebark pine nuts from disease, berry crops from timing desynchronization, and salmon from temperature-affected runs — creates nutritional shortfalls that affect individual animal welfare and population health simultaneously. Bears that must compensate for natural food shortfalls by foraging in agricultural areas or near human settlements face the additional welfare threat of lethal conflict response. The individual welfare of each bear entering winter depends on conditions shaped by climate policy, land management, and food crop conservation interventions.