Do European hedgehogs still hibernate? How climate change shifts hedgehog behavior

European hedgehogs (Erinaceus europaeus) are traditionally known as true hibernators, relying on a long winter sleep to survive cold months when food is scarce. However, recent years have brought noticeable changes in their behaviour across Europe, especially in countries with milder winters such as the Netherlands and the United Kingdom.

Warmer, wetter winters and unpredictable weather patterns are changing how hedgehogs prepare for (and move through) the coldest months of the year. Some individuals now hibernate for shorter periods, wake up more often, or skip hibernation almost entirely.

This article explains what we currently know, why it is happening, and what wildlife carers and garden owners should be aware of.

Hibernation in European Hedgehogs

Hibernation is not a fixed, rigid process. Hedgehogs use it as an energy-saving strategy, not as a biological requirement. If winter temperatures remain mild and food remains available, hibernation becomes shorter or more fragmented.

Wildlife biologists in the UK note that hedgehogs in warmer regions of Europe often remain active throughout winter. Even in the UK itself, hibernation varies significantly between individuals. Some may sleep for months, while others enter only light torpor or wake repeatedly.

This natural flexibility allows hedgehogs to adapt, but it also creates new challenges—especially when mild weather is followed by sudden cold snaps.

What Research in the UK Shows

Multiple studies from British ecologists reveal clear trends:

1. Later start and earlier end of hibernation

Long-term monitoring indicates that hedgehogs now begin hibernation later in the season and wake earlier. Combined, this shortens the total hibernation period.

2. Greater variation between individuals

One study tracking hedgehogs in semi-rural England found enormous differences in when animals entered and left hibernation. Every hedgehog hibernated, but not in the same way or for the same duration. Researchers suggest this behavioural flexibility may be a response to climate change and urban heat islands.

3. ncreased mid-winter activity

Wildlife rescue centres report that hedgehogs appear active at times of the year when they would normally be asleep. Many arrive underweight or dehydrated after waking during a warm spell.

Together, these findings support the idea that hedgehogs are adjusting their survival strategies to changing climatic conditions.

What We See in the Netherlands

Dutch wildlife organisations have documented a similar pattern:

Warm, unpredictable winters

The Netherlands has experienced increasingly mild winters. Hedgehogs may wake up whenever temperatures rise above freezing, sometimes repeatedly.

More late-season babies

Because warm autumns extend the breeding season, many “autumn juveniles” are born too late to reach a safe hibernation weight. Wildlife rescue centres see a sharp rise in these youngsters every year. Many must overwinter indoors because they cannot safely hibernate.

Some individuals skipping deep hibernation

In especially mild winters, some hedgehogs remain partially active. They may sleep lightly or for short periods instead of entering deep torpor.

Urban areas amplify the effect

Cities retain heat, and gardens often provide supplemental food. As a result, urban hedgehogs are more likely to stay active during mild periods, even in mid-winter.

How Climate Change Drives These Changes

The hibernation cycle of hedgehogs depends heavily on:

• Temperature
• Food availability
• Photoperiod (day length)
• Body condition and fat reserves
• Habitat quality

Climate change disrupts several of these factors at once.

Warmer winters

Europe’s winters are becoming consistently warmer, especially in the UK and the Netherlands. A small increase in temperature can prevent hedgehogs from entering deep hibernation or cause them to wake too frequently.

Sudden weather shifts

Warm spells followed by freezing nights can be deadly. Hedgehogs burn energy waking up and searching for food, then cannot find enough to survive the next cold period.

Drier summers

Hot, dry summers limit insect availability. Hedgehogs struggle to build sufficient fat reserves, making hibernation riskier.

Urbanisation

Heat islands, artificial lighting and urban gardens offering food all influence winter behaviour.

In short: hedgehogs are responding flexibly to a changing climate, but flexibility does not always mean safety.

Is It True That Some Hedgehogs Do Not Hibernate Anymore?

Partially.
Most hedgehogs still hibernate, but research and field observations confirm:

• The duration of hibernation is decreasing.
• The frequency of mid-winter awakenings is increasing.
• Some individuals (especially in warm, food-rich urban environments) may skip deep hibernation or hibernate only lightly.

This does not mean hibernation has “disappeared,” but it is no longer a reliable, predictable behaviour in mild climates.

Why This Matters for Conservation

Changes in hibernation create several risks:

1. Energy loss during mid-winter activity

Waking up burns significant fat reserves. If food is scarce, hedgehogs may starve.

2. Increased vulnerability to predators and cars

A hedgehog searching for food during an unusual warm period may wander into danger.

3. Higher winter admissions in rescue centres

Autumn juveniles and underweight adults need human care more frequently.

4. Long-term population stress

Climate-driven changes, combined with habitat loss, traffic, pesticides, and urbanisation, may exacerbate the ongoing decline of European hedgehog populations.

What Garden Owners Can Do

You can help hedgehogs adjust to changing winters by creating a safe, food-rich, climate-resilient garden:

• Provide nesting places such as log piles, hedgehog houses or natural brush piles.
• Ensure access to water (never salt-water or milk).
• Offer supplementary food during warm winter spells—meaty cat food or hedgehog kibble.
• Avoid disturbing leaf piles, compost heaps or garden corners where hedgehogs may sleep.
• Reduce pesticide use and increase native planting to support natural prey.

Small actions in private gardens collectively have a large impact on local hedgehog populations.

Conclusion

Hibernation has not disappeared in European hedgehogs, but it is changing. A combination of climate change, urbanisation, and shifting food availability is causing hedgehogs in the Netherlands, the UK, and other regions to adapt their winter behaviour. Some sleep less, some wake more often, and a small number remain active for much of the winter.

Understanding these changes helps us better support hedgehogs through the cold months and prepares conservationists for the challenges ahead.