Hedgehog hibernation is a carefully timed physiological process increasingly disrupted by climate change, with mild winters causing premature arousal that depletes fat reserves and threatens survival.
Climate-disrupted hibernation causes hedgehog deaths from starvation that are preventable through targeted intervention. Hedgehogs that arouse from hibernation in January during a warm spell and find no invertebrate food are physiologically compromised when cold returns. Late-born juveniles that have not reached adequate weight face near-certain death in their first winter. Supplementary feeding of clearly underweight hedgehogs through autumn, combined with provision of insulated hibernation boxes, directly prevents individual deaths. These simple interventions multiply welfare impact across millions of garden-visiting hedgehogs.