The hazel dormouse is one of Britain's most elusive mammals, facing habitat loss and climate change threats that affect population welfare through disrupted hibernation and food scarcity.
Dormouse welfare is intimately connected to the welfare challenge of hibernation - a physiological strategy that has become increasingly risky in an unpredictably warming climate. Dormice accumulate fat reserves during autumn and depend on complete physiological shutdown during winter months when food is unavailable. Climate warming is disrupting this balance: mild late-autumn conditions tempt dormice to remain active longer, burning reserves, while early spring warming may trigger premature arousal before sufficient food is available. Dormice that emerge too early exhaust reserves before insects and blossom are available, dying of starvation or remaining torpid in periods of insufficient food. Habitat fragmentation prevents dormice from making the movements necessary to find adequate food during the active season - isolated woodland patches cannot support the dietary diversity dormice require through the seasons. Welfare monitoring using nest box surveys allows population health assessment but also enables early identification of animals in poor body condition, allowing targeted habitat intervention where food availability is limiting welfare.