The Hedgehog's Dilemma

by Hugh Warwick

  Pat had already shown that adult hedgehogs, nursed back to health, cope very well when returned to the wild, though one of his hogs was unfortunately run over right by the sign leading into the Essex town of Dedham. We were looking at the most vulnerable group, juveniles, and in particular the autumn orphans, those young hedgehogs taken into care in their droves when they are found wandering forlornly in the run-up to hibernation.

  Hedgehogs, four or five per litter, are usually born in June and early July, after a four-and-a-half-week gestation, but there can be second, or late, litters, resulting in young emerging much further into the year.

  These late arrivals have a very poor chance of survival as they simply do not have enough time to put on the necessary weight to live through hibernation. They will often be seen out during the day as they try to cram in extra time to feed. If they look drunk, then they have the onset of hypothermia and are going to die unless looked after. Most of these hedgehogs are not really orphans, as hedgehog parenting is a pretty limited affair – the father has no part to play in their upbringing and after six weeks the mother gives them the heave-ho – but it is a useful shorthand for the youngsters that are in such a parlous state.

  If hedgehogs enter hibernation weighing less than about 450 grams, they will die. The main problem they face is a lack of brown fat. There are two sorts of fat being laid down by hedgehogs as they prepare to hibernate. White fat is the basic day-to-day fat that keeps the animal alive, ticking over the metabolism at a remarkably low level: heartbeats down to five per minute and periods without drawing breath of up to nearly an hour. The physiology of the hibernating hedgehog is fascinating. The blood changes, the nervous system changes, the hormonal system changes. In fact, it can be hard to tell whether a hedgehog is hibernating or dead just by looking at it. If you find a hedgehog in the winter it is best to simply re-cover it with vegetation, but should you need to know whether it is alive, then stroke the spines. There ought to be a bristling response. Unfortunately, too many disturbances will prematurely use up the other sort of fat, brown fat. This is the starter motor and its absence will leave the hedgehog torpid until death.

  Hedgehogs do not need to hibernate. It is just a survival strategy, so if there is no reason to – that is, if there is plenty of food available – they will stay wide awake. On the North Island of New Zealand, for example, hedgehogs rarely hibernate, or do so only briefly. And when hibernating, it is not a constant state of torpor. They might get up and have a wander, especially when the winters are mild.

  Talking to wildlife carers and hedgehog rescuers around the UK, there is near unanimity in the observations of a distinct change in hedgehog behaviour: hedgehogs are spending less time in hibernation, if they are hibernating at all. Carers are being brought active hogs all winter long; one even had a baby brought in in January. That is not to say that hedgehogs have stopped hibernating – you still need to check any winter bonfires for sleeping hogs before ignition – just that phenology, the study of nature’s rhythms, can indicate changes in the environment, perhaps before we even feel them. Is the world warming up? We may not notice a subtle shift of a fraction of a degree, but hedgehogs might.

  The strategy of hibernation is employed not because hedgehogs themselves cannot survive the weather, but because their invertebrate food vanishes out of reach. This is also true of other species of hedgehog living in very different environments. For example, African desert hedgehogs’ main threat to survival is not the cold, but the heat. And the reaction is not hibern[winter]ation, but aestiv[summer]ation.

  To find out how well these rescued orphans survive, my job was to spend a couple of months following twelve that had spent the winter – proving hedgehogs do not need to hibernate – feasting at the RSPCA wildlife hospital at West Hatch in Somerset. Some of them were really rather rotund by the time I arrived.

  Rescued orphans are very naive. They have no opportunity to learn the ropes of hedgehog life under the watchful eye of a mother. Would they be able to rely on instinct when confronted with their new home? Would they be able to find food, build nests and interact with other hedgehogs in a normal hedgehoggy way?

  All the animals to be released had been found the previous autumn – juveniles too small to survive hibernation. Nigel – yes, I named all twelve – had been wandering around in daytime in late September, weighing less than 100 grams, near a nest damaged by a mower. He would certainly have died if he had not been taken into care. Some of the others had had an even worse start. Hettie had been found in October with one of those wretched plastic rings used for holding cans in four-packs stuck round her middle. As she had grown, it had cut into her flesh and the wound had become infested with maggots. It is such a simple thing to cut up those bits of plastic before putting them into the bin – and it can save lives of so many animals, not just hedgehogs.

  Each of my twelve, and I very quickly became proprietorial, had a small radio transmitter attached to a patch of clipped spines on their back. The transmitter included a luminous tag, which glowed green and was invaluable in helping to find the hedgehogs – though it was potentially alarming for the uninitiated to see little green lights travelling through gardens and Welds.

  We released the animals in two batches. The first was simply let go. The second was provided with food and bedding and kept in pre-release cages for five days. The cages were then opened, but food and bedding were placed in them for another five days, giving the hedgehogs somewhere to retreat if they failed to acclimatize in the wild. We already know that some species, such as dormice, need to be treated like this and if we found hedgehogs benefited, then we could pass the experience on to the thousands of hedgehog rescuers around the country. Our results showed that there was little difference in how hedgehogs fared in the two groups. This is encouraging, as most people just release hedgehogs into the wild following time in care.

  Nigel and Hettie were both released in the second batch. Hettie had a more subdued, though no less endearing character. She would remain quite relaxed when picked up for her nightly weighing session – a brief indignity involving the animal being placed in a converted pillowcase hooked beneath a spring balance. Keeping a record of the weight was an essential part of the study, because we needed to know if the newly released hedgehogs were eating properly (if they weren’t, they would lose weight very rapidly). This would not only indicate their wellbeing, but also give us an idea if the hedgehogs were coping with the new environment.

  Given the naivety of these animals, I was worried that the seven months of cosseting they had received might have affected their ability to cope with life in the wild. And if the answer to my study was that they really were unable to reintegrate into hedgehog society after such intensive care, this would question whether there was any point to it in the first place.

  If only the caravan had been a little warmer. But at least the Calor gas stove helped melt the ice on the windows as I cooked yet another pan of brown rice and vegetables for my dinner.

  While on the subject of eating, I met David Bellamy and, as one does, got around to talking about hedgehogs and he revealed something that might shock his once loyal audience. Professor Bellamy is a self-confessed hedgehog eater.

  Actually, eating hedgehogs is not such a problem. His was roadkill cooked with a stuffing of wild herbs. And even though I have not eaten meat for over twenty years, I can see the logic of not allowing good protein to go to waste. Perhaps one day . . . Maybe it would mark a true coming together of the hedgehog and me?

  It is one of the most repeated stories that surround hedgehogs – ‘The Gypsies eat them, don’t they?’ The story goes that you wrap the hedgehog in clay and then cook it in an oven, or perhaps in a fire. When the meat is done you just crack open the newly fired pot and the spines magically come away from the flesh. But is this really true?

  I have read that this method of cooking, unless done in a very large fire, will result in a soggy mess. One school of thought is that it’s best to chop the h
edgehog up to use in a recipe, as Arthur Boyt described in the Guardian in 2006:

  Hedgehog spaghetti carbonara (serves four)

  500g spaghetti, 30ml olive oil, 250g lean hedgehog, 1 medium onion (chopped), 125ml water, 60ml dry white wine, 4 eggs, 60ml double cream, 100g grated Parmesan cheese

  • chop hedgehog into small chunks

  • beat eggs and cream together in a bowl, and add half the Parmesan cheese

  • put pasta in boiling water

  • put onions and hedgehog chunks in pan with olive oil on medium heat until onions are almost clear

  • add wine and reduce heat

  • drain pasta when cooked, and combine it with egg, cream and cheese mix

  • add meat, onions and wine without draining fat and mix thoroughly

  • garnish with remaining Parmesan

  • serve immediately

  Arthur specializes in cooking up roadkill. In fact, it sounds like he will eat pretty much anything he finds (the Labrador had no collar – and tasted a bit like lamb). But not all hedgehog eaters are clearing up after the murderous rampage of the motorcar. I came across a debate on a website dedicated to hunting wildlife where one contributor talked of meeting travellers who had bred a strain of terrier specifically for catching hedgehogs. He described the hedgehog meal he was given as ‘a bit greasy but OK white meat a bit like young rabbit, but I reckon you’d need one per person . . .’

  I got an email from Alan Birks describing his post-war experience with hedgehogs while on holiday as a child in Rhyl when he made friends with a Gypsy boy who invited him back for supper:

  They asked me if I had ever tasted hedgehog and then began to prepare it. I do not know how they killed it but they had a brick oven in the garden and they covered the hedgehog in clay and put it in the oven. Some time later they cracked open the clay and all the spines remained attached to the clay. I was unsure but I tasted it and it tasted like watery chicken.

  Evidence of hedgehog eating goes way back. In 1699 Jezreel Jones published ‘An Account of the Moorish Way of Dressing Their Meat’ in the learned journal Philosophical Transactions:

  The Hedgehog is a Princely Dish amongst them, and before they kill him, rub his Back against the Ground, by holding its Feet betwixt two, as Men do a Saw that saws Stones, till it has done squeaking; then they cut its Throat, and with a Knife cut off all its Spines and singe it. They take out its Guts, stuff the Body with some Rice, sweet Herbs, Garavancas, Spice, and Onions; they put some Butter and Garavancas into the Water they stew it in, and let it stew in a little Pot, close stopped, till it is enough, and it proves an excellent Dish.

  Earlier still, according to experimental archaeologist Jacqui Wood, hedgehogs would have formed a part of prehistoric diet. She told me:

  Clay baking is the most effective way of cooking hedgehogs or small birds, as you do not have to bother with the spines or the feathers. When baked they come away from the flesh beautifully. The only experiments I have done with hedgehogs are with fresh roadkill, so I know it does work and they do taste like pork, hence the hog in the name.

  Back to Nigel, Hettie and the rest of the team. To get to know them I had to adopt their lifestyle, up to a point – I might be fond of them, but I was not up for sharing their dinner. For two months I would poke my nose out into the world as the sun fell, curling up to sleep when it rose.

  And the more time I spent with the hedgehogs, the more it became clear that their allotted identification numbers, which were in fact the frequencies of the radio transmitters attached to their backs, were too formal. So to the pressing matter of naming hedgehogs.

  After the first few days, when it became clear that number 288 liked to disappear at great speed, Nigel was named after a not so proficient racing driver. He would cause me confusion by making it from one end of a field to the other before me. I would see a green glow, get excited at an easy catch (sometimes it took ages to track down a hedgehog) and then find it was Nigel, again.

  He was a very useful hedgehog. Not only was he busy, he was also very accepting of my presence and began to allow me into his world. One night I followed him out on a hunting expedition. Down the quiet lane he jogged – I was required to walk at a reasonable pace to keep up. Every now and then he swooped on an unsuspecting morsel, usually so fast that I could not see what he was eating. Eventually I got a glimpse – small slugs. I am often tackled on the subject of slugs: people will tell me that they have hedgehogs in their garden, but there are also still slugs.

  Well, there is a thing about slugs – not all of them are bad. We are well aware of the chaos that evil slugs can wreak in a bed of carefully nurtured seedlings, but we are less aware of the wonderful things that other slugs, the detritivores, get up to. You may have heard tell of the wonders performed by dung beetles – and the idea that if it were not for them Africa would be knee deep in Elephant poo. Well, some slugs do similar, if less dramatic, work around the garden, aiding the decomposition of leaf litter. So before you set about the complete eradication of slugs, consider the consequences, and also consider that you will be removing lots of hedgehog food as well.

  Many of the slugs that the likes of Nigel are gobbling will be small, but the slugs we are likely to see around the garden are the great big slime monsters. I have a habit of walking around barefoot when the weather is nice and there is little as unpleasant as treading on a slug – the slime is persistent (one piece of advice I heard was to try shaving it off).

  Back to Nigel: he found a black slug that was rather larger than any I had seen him tackle so far. Scrabbling at it, he rolled it back and forth across the tarmac and then he ate it. After he moved off, I examined the ground and found it was covered with slug slime. It looked like he had been deliberately removing the unpleasant mucilage to make the slug more palatable. I have seen blackbirds do something similar, wiping a slug on the pavement.

  I suspect the tactic didn’t work, because his next point of call was a dandelion leaf, which he avidly ‘mouthed’ before spitting it out. Nigel then started smacking his lips and contorting himself in his efforts to spread a froth of saliva on to his spines – a wonderful display of self-anointing.

  Such an unusual noise was coming from Nigel that I pulled my recording equipment out and stuck my microphone close to him – you shouldn’t leave home without one, as you never know when it might be needed. His response was to puff himself up and snort. Though this aggressive display did have the desired effect of making the microphone retreat, it also provided some wonderful noises for the tape.

  While self-anointing is usually associated with particularly strong flavours, there is no specific chemical that sets it off. It has been prompted by distilled water. I have seen it when people wearing perfume, or who have washed their hands in scented soap, have handled hedgehogs, but the most frequently quoted stimulus is an old leather shoe.

  Why? No one knows for sure. Each idea seems plausible up to a point – but then fails. Perhaps it is an attempt to rid themselves of fleas, yet flea-free hedgehogs do it. Or to coat the spines with a toxin, to make the hedgehog more repellent to potential predators, but it can be caused by the most innocuous of substances. Perhaps it is a device for disseminating scent more effectively. This, so far, seems the best theory and other mammals are known to have scent carried in saliva. The surface area afforded by the spines would give a great platform from which evaporation could occur.

  So Nigel was hunting – he was eating – and this was great news. The first thing to show a problem in a released hedgehog will be a failure to eat, at which point they will start to lose weight. That is why checking the hedgehogs’ weight each night was so important, even if getting tipped into a modi fied pillowcase and dangled beneath a spring balance was not particularly elegant.

  The other key piece of data I was collecting was the location of the day nest. This served two purposes: it gave me a better idea of where to start looking as the next night began and also revealed how well the animals were co
ping in their new environment. Not as simple as weight loss, but if a hedgehog either used one nest all the time or kept making a new one every morning, well, this would be abnormal behaviour, suggesting that something was wrong, perhaps that the time in captivity had affected their ability to nest properly.

  Some nests I have seen are as intricate as a bird’s. Hogs make two sorts of nest: the day-to-day day nest and the more substantial hibernaculum. The day nest can be pretty flimsy, depending on the weather. I have found healthy hedgehogs covered in little more than a scattering of leaves. Others have made quite a serious effort, pulling vast amounts of vegetation with their mouths into a thicket of brambles. The combing effect of a rotating hedgehog should not be underestimated.

  The hibernaculum, on the other hand, is a far more substantial construction, 50 centimetres in diameter, with walls of leaves up to 10 centimetres thick. Pat Morris found that good nests can be fantastically well insulated, keeping the internal temperature between 1 and 5 degrees centigrade while the outside temperature fluctuates between –8 and +10. Avoiding frostbite is an obvious need, but it is equally important that brief rises in temperature do not arouse the hedgehog prematurely.

  Similar qualities of insulation would have been appreciated in my caravan. At least it kept the rain out – it seemed to rain on every single day of the first month of the project and the radio-tracking receiver had a warning on it in bold letters: DO NOT EXPOSE TO MOISTURE. When it got wet, it stopped working.

  But there were nights when everything worked wonderfully. Or at least the kit did. The hedgehogs were, as it soon became apparent, a law unto themselves.

  Hedgehog number 298 had vanished. It was only her second night out and she was nowhere to be seen or heard. The radio receiver I was carrying picked up nothing but static, with the occasional, tantalizing respite hinting that there might be a firmer signal if I just went a bit closer to where I did not want to go.