Wild Hedgehog Hibernation: Welfare During Winter Sleep

Hedgehog hibernation is a critical survival strategy, but increasingly mild and unpredictable winters are disrupting hibernation patterns with welfare consequences for individual animals.

Key Facts

Hedgehogs typically enter hibernation in November and emerge in March-April, depending on temperature
Body temperature drops from 35 to as low as 2 degrees Celsius during hibernation
Heart rate reduces from 190 beats per minute to as few as 20 during deep hibernation
Insufficient fat reserves before hibernation are the leading cause of winter hedgehog mortality
Hedgehogs may wake and move during mild winter spells, burning critical fat reserves
A hedgehog weighing less than 450g in October is unlikely to survive hibernation without intervention
Climate change is causing shorter, warmer winters that disrupt hibernation onset and duration, increasing energy expenditure

Welfare Considerations

Hedgehog hibernation welfare depends on adequate pre-hibernation fat stores and stable cold temperatures. Mild winters trigger premature waking events, forcing hibernating hedgehogs to expend energy moving and foraging when little food is available. Each waking event depletes critical reserves. A hedgehog that enters hibernation underweight faces near-certain winter mortality. Garden supporters can provide supplementary food in autumn to support weight gain and undisturbed hibernation sites throughout winter.

What You Can Do

Provide supplementary hedgehog food (not bread or milk) in autumn to support pre-hibernation weight gain
Build or purchase a hedgehog hibernation house positioned in an undisturbed corner of the garden
Never disturb hibernation sites - waking a hibernating hedgehog wastes critical fat reserves
Weigh any hedgehog seen active in October-November; those under 450g should be taken to a rescue for supplementary feeding