Hedgehog Hibernation: Welfare in the Wild and in Care

Western European hedgehogs enter hibernation in winter, but changing climates and garden hazards create new welfare challenges for this beloved but declining species.

Key Facts

West European hedgehogs (Erinaceus europaeus) typically hibernate from November to March, though the timing varies with temperature.
During hibernation, body temperature drops to near ambient levels, heart rate falls from 190 to 20 beats per minute, and breathing nearly ceases.
Hedgehogs need to reach a body weight of at least 450-500 g before hibernation to have sufficient fat reserves.
Autumn orphans and sick individuals below this weight are at high risk of dying during hibernation.
Mild winters disrupt hibernation: hedgehogs may emerge during warm spells and deplete their fat reserves without adequate food.
Garden hazards including bonfires (hedgehogs shelter in bonfire piles), garden netting, strimmers, and slug pellets cause significant mortality.
UK hedgehog populations have declined by approximately 50% since the 1990s, driven by habitat loss and fragmentation.
Wildlife rehabilitation centres admit thousands of underweight hedgehogs each autumn for overwintering care.

Welfare Considerations

Hedgehog welfare in the wild is under increasing pressure from a combination of habitat degradation, garden hazards, and climate disruption. Hedgehogs brought into care because they are underweight or injured require specialised, extended support; simply releasing them without reaching adequate weight is a welfare failure that leads to hibernation death. Rehabilitators face the challenge of providing appropriate nutrition to promote weight gain without causing metabolic disorders, and of maintaining hedgehogs in conditions that do not prevent normal hibernation. Public education about garden practices — checking for hedgehogs before lighting bonfires, removing netting, avoiding pesticides — is a high-impact intervention for this species.

What You Can Do

Check bonfire piles for hedgehogs before lighting, and always build fires on the day they will be lit.
Remove or raise garden netting at ground level that can trap hedgehogs.
Create hedgehog gaps in garden fences to allow movement between green spaces.
Avoid using metaldehyde slug pellets, which poison hedgehogs.
Provide supplementary food and fresh water in autumn to support pre-hibernation weight gain.
Support hedgehog rescue organisations and wildlife corridors in your area.