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Research in the 1970s by Britain’s foremost expert on hedgehogs, Dr Pat Morris (formerly of Royal Holloway, University of London), revealed a direct link between hibernation and climate: hedgehogs came out of hibernation up to three weeks earlier in the South West of England compared to Scotland.  Furthermore, in East Anglia, hedgehogs similarly spent longer hibernating than in the London area or South West.  This marked difference in hedgehog hibernation patterns across the UK shows a general trend of prolonged inactivity in proportion to the coldness of the winter.

Dr Morris explains: “Age, sex and weather all appear to influence the timing of hedgehog hibernation.  For example, young animals may remain fully active into December, no doubt seeking to develop sufficient fat reserves to ensure survival during subsequent hibernation.  Also, adult females that have had late litters or may still be lactating will need to feed intensively before hibernating, causing them to be active for longer than adult males.  However, mild weather can also delay hedgehogs entering into hibernation or elicit premature awakening, impacting on the creature’s fat reserves and breeding times and consequently affecting the long-term survival of the species.” 

The 2012 Hedgehog Hibernation Survey proved to be fantastically popular, with around 2,000 people logging around 45,000 hedgehog sightings through the online form. This makes it one of the largest datasets about hedgehog activity ever collected.

This map shows that sightings were widely distributed, with the vast majority (90%) of them spotted in gardens. There were two peaks in hedgehog activity across the country: the first, in April and May, corresponds with when we would expect the hedgehog breeding season (‘the rut’!) to begin; the second, between the end of July and the beginning of August, is perhaps related to the first flush of inexperienced young hedgehogs leaving the safety of the nest and their mother’s stewardship. Regional patterns of hedgehog emergence from hibernation did not match those seen in the 1970s study, and the reasons for this are unclear. Potentially the unusually mild weather in February, March and April of 2012 has had an influence. This is why we have decided to repeat the survey this year. It will also take several years of recording before we can establish the impact of broader changes in the global climate.

Read the 2012 Hedgehog Hibernation Survey report.

Frequently asked questions about the survey...