How to help hedgehogs hibernate

How climate change is affecting our prickly friends
10 November 2023

Interview with 

Hugh Warwick, British Hedgehog Preservation Society


Hedgehog outdoors


November can be a particularly prickly time for hedgehogs in the UK as they dodge fireworks party bonfires and prepare for hibernation. But this year, their plans to sleep through the winter have been disturbed by both unseasonably warm weather and heavy flooding in large parts of the country. It’s meant that rescue centres have been inundated with referrals. So, what should we know about hedgehogs and how we can help them? Hugh Warwick is an author, ecologist and a spokesperson for the British Hedgehog Preservation Society.

Hugh - The UK's only spiny prickly mammal has made this fantastic compromise. They've lost the great insulating fur of other similar sized animals like rabbits and things. And they've got this defensive coat, which is great for many things, but it doesn't provide that warm coat which helps survive the colder weather. And so what you've ended up with is, they need to find a way of surviving through a time when their food, which is insects, invertebrates, and that sort of thing, is not readily available. And they do that by shutting themselves down. They go into hibernation. And the problem this presents the hedgehog is that they are uniquely vulnerable at this time. And the challenge that they face is getting enough fat reserves stored up so that they can cope with a time of inactivity over the colder months.

Chris - How do they reproduce? I suppose the stock answer is carefully, but how do they?

Hugh - So hedgehog courtship is a wonderful thing. It involves a lot of snuffling around, and as I do a lot of talks to the wonderful groups like the Women's Institute, and I have to point out that mating cannot take place while a female frowns, which always generates quite a degree of hilarity. So they're famous for rolling up into a ball when they're frightened. But the first thing a hedgehog does is it frowns and that frown muscle extends from above the nose down to the tail, and it brings a spines up in a sort of prickly jagged mess. So an upset female mating cannot take place. Once the male has circled and circled and circled a receptive female, she will relax and that will allow mating to take place,

Chris - <laugh>. And when do they do that? When's reproduction and when is this hibernation period for them?

Hugh - So where are we now? We're recording this on the 6th of November. Around this time of year, the hedgehogs are looking for somewhere to hibernate. Between November and March. In March they begin to emerge from hibernation. And by April they tend to be out and about snuffling and courting. And then mating will take place from that moment onwards.

Chris - Do they come out at all during that hibernation or is it literally one long sleep?

Hugh - So researchers found our hedgehogs will arise from hibernation throughout this winter period, and in fact, sometimes they'll change their nests during that time as well. So it's not a completely continual sleep pattern. The hedgehogs further north, which you can find up in Norway, will tend to go into hibernation and it tends to be a bit more of a 'it's pretty cold out there, we'll stay in this until spring comes.' Whereas here where we've got longer wetter winters, which can be at times quite mild, they can be stimulated out of hibernation.

Chris - And is that the problem we've got at the moment? The fact we've got a lot of groundwater and this is flushing them out of their homes in some cases.

Hugh - Groundwater is a problem when there's lying water and there's flooding because a hedgehog in hibernation will drown if it's covered in water. It's been very mild. So hedgehogs will probably only be beginning to think about going into hibernation. I think one of the issues is that the mildness is keeping hedgehogs awake longer than they would anticipate. And so you end up with quite small individuals being found at this time of year. We know that a hedgehog weighing less than 450 grams won't survive hibernation. And so people are finding these ones out and about and when you get sudden storms, we've had lots of rain of late, that will displace hedgehogs from day nests. It will get them up and about and then they'll be seen tottering around the garden looking like they may be a bit drunk. And that just means they've got hypothermia and they are on their way to death unless somebody intervenes.

Chris - And what can the average person do in their own grounds around their own home if they know there are hedgehogs active there to help them out?

Hugh - What it boils down to is don't be so tidy in your garden. If you really want to help hedgehogs, make sure there's vegetation, make sure there are piles of leaves. Make sure there's a log pile, make sure there's a bramble patch. Make sure there's a compost heap. All of these sorts of things provide structures in which hedgehogs can make a really good nest and they provide a lader of food. On a bigger picture, if you really want to help hedgehogs, I would suggest looking at changing the way we grow food, changing our transport infrastructure, altering the national planning policy framework and possibly looking to dismantle industrial capitalism. But those can all be a little out of the reach of most people and their gardens. So maybe start with getting your garden a little bit more untidy before moving on to societal change.

Chris - Are there any mega no no's? Because I do hear people say it's terrible to do what some people do and put things like milk and that kind of stuff down. This is not good.

Hugh - Hedgehogs have a reputation for enjoying drinking milk, and this comes from years and years and years of people doing that. And hedgehogs will drink milk. The trouble is hedgehogs are lactose intolerant and that they don't know that they're lactose intolerant. And so it can give them an upset tummy. Hedgehogs are carnivores, their favourite food throughout the year. Worms, beetles, caterpillars and insects, all sorts of things. And if you want to help them with food, kitten kibble is actually one of the easiest things to give them. And in dry spells lots and lots of water as well.


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