by Hugh Warwick
The more time I spent with them, the more I realized that for some, at least, this was little more than glorified trainspotting, meeting a need to collect and catalogue. Obviously counting hedgehogs is an entirely more reasonable enterprise.
Sometimes it felt rather like it was us against the ornithologists. And as my companion began to be seduced (not just by birds) it was very much me against the hedgehog-hating world.
I am pretty open-minded, happy to spend time with birds as well as mammals. So I made a concerted effort to see what pressures the birds were under, and focused on the Arctic tern. This slight, angelic-looking bird is a wonder of the world. Emerging from an egg on North Ronaldsay, it grows up rapidly in preparation for the longest migration of any species. As our days begin to shorten it heads south; not south as in Costa del Sol south, but really south. Arctic terns can do a round trip of 35,000 kilometres, all the way down to the Antarctic and back again.
As beautiful and amazing as this animal is, there are considerable disadvantages in choosing it for a species to study. This was rammed home with some vigour when I accompanied people from the observatory as we headed out along a stretch of shingle, trying to find tern nests with chicks. The plan was to put a small ring on the leg of each chick found – part of the international effort to track birds.
The first to suffer had the disadvantage of being, as he put it, ‘5 foot 20’ (fed up of being asked just how tall he was). Blood trickled down his face from the wound on his scalp caused by the beak of a very angry tern. Another assistant warden took heed and placed his tobacco tin under his rarely removed woolly hat. The work was punctuated by occasional sounds of beak on tin as his protection proved its worth. I tried to stay close to the tall guy.
The hours I spent sitting at the margins of a tern colony monitoring the amount of food being brought in to the chicks were some of the most nerve-jangling of my life. Measuring the amount of food required that I assess the size of the sand eels carried in by the parents. These small fish are a staple of much marine life – fulmars, kittiwakes and guillemots depend on them. Watching each delivery through binoculars, I had to compare the length of the sand eel with the length of beak – a very simple yet effective tool.
Common terns also visit the island and it still tickles me that if birders are not sure if they have seen a common or an Arctic tern, the accepted shorthand is ‘comic’.
My Arctic terns did not have it all their own way on the persecution stakes. As they tried to deliver their cargo of fish to their chicks, they would frequently come under attack from Arctic skuas loitering around the edge of the colony. These agile birds are well named in Latin, Stercorarius parasiticus; they are kleptoparasites. They steal fish from smaller birds by chasing them until they drop their hard-won cargo.
And hedgehog hunters don’t have it all their own way either – similar kleptoparasitism was in evidence at the bird observatory as one of the wardens swooped in on my girlfriend. I emptied a vomiting fulmar over him in a show of impotent petulance. His clothes will have stunk for weeks. Made me feel better.
Nights out with the hedgehogs were sometimes magical and sometimes farcical. The sublime was offered by shooting stars and the northern lights; the ridiculous came from the interruption by a wire fence to an enthusiastic dash by my soon-to-be ex. Face down in a field of cow dung. Made me feel better.
Reprieve came in the form of the summer dance, a very pagan event where islanders celebrate life by trying to drink themselves to death – a ceilidh like no other.
Two Olympians pulled me into the mêlée for the ‘Dashing White Sergeant’: two women leading one clueless man. This was not a sensual and provocative dance; this was a failed attempt at maintaining my dignity. Alcohol was absorbed in the traditional banana sandwich break, followed by more alcohol as islanders toasted their Viking heritage and the small band of accordion, fiddle and drums started up again.
Unable to compete in the grand excess of drinking and already rather bruised from the eightsome reel, I wandered outside into the perpetual twilight of Orkney summer – cooling, fresh and pleasantly lonely – and there was a hedgehog, reminding me that it was still office hours.
I was keeping a record of the weights of the hedgehogs because, in the first study, it looked like these island hogs were on the large side. And again, the data were clear: males averaged 971g, females 828g, around 30 per cent heavier than their mainland relatives. This could be because the two original imports were on the robust side of average, or it could just have been all those birds’ eggs. The data also revealed an unexpected difference between the sexes. On the mainland hedgehogs usually weigh 600–700 grams, with little difference between male and female.
Whatever their size, something I have grown to realize is that hedgehogs are more often heard than seen. Certainly at home in Oxford I am much more likely to hear the distinctive snuffling as they trundle through the undergrowth. But on North Ronaldsay the almost constant wind made this much less likely. There was one behaviour, however, that I would invariably hear before I saw – and this is a behaviour that regularly gets hedgehogs into the newspapers: courtship.
Hedgehog courtship is an understandably cautious process, for the male in particular. This is a species where no really does mean no.
Females can be fertile any time from when they emerge from hibernation in April until they begin to get ready for it again in September, though the main period for courtship is May and June.
When a male comes across a female that is exhibiting some evidence of being fertile – that is, she smells just right – he will begin to make advances. More often than not, judging by the times I have witnessed the behaviour, the female rebuffs him with a small jump forward and a sneeze-like plosive. This is the strange huffing and puffing that many a householder has been disturbed by at night, frequently resulting in letters to the papers, or calls to the police. As happened in Bremen, Germany, when a couple were disturbed by strange noises. The police arrived and shone torches, finding two hedgehogs described unusually eloquently by the police spokesman as being ‘loudly engaged in ensuring the continuity of their species’.
The fear that this noise can engender should not be sneezed at. I got a letter from a Caroline Sykes recently in which she describes vividly the horror of being in a very quiet caravan park in Worcestershire with her four daughters and hearing what conjured up for her a ‘sexual pervert’ and then ‘a deer impaled on the fence gasping its last agonized breaths’. Almost hysterical with fear, she ran to the warden’s chalet. He emerged, listened to the story, got a shovel and strode out in silence. He scooped under the caravan and sent something flying into the woodland nearby. ‘Hedgehogs,’ is all he said as he stomped back to bed.
This is not the only noise a hedgehog makes. One hedgehog rescuer in Twickenham, Greater London, related a wince-inducing tale. She had just been handed a bundle of four baby hedgehogs from a disturbed nest. No mother to be seen; yet they stood a good chance of survival in her capable hands. She went to make up some more formula milk to give them a feed when the air was split with a terrifying screech. She dropped everything and ran to find one of the babies screaming in agony, as one of the others frantically suckled at the closest thing she could find to a teat: his penis.
A courting male continues his noisy pursuit of the female, trying to get around to her rear; she continues to turn with obstructive obstinacy. This merry dance can continue for hours – well, not so merry really; it does look rather grumpy. But the circling continues and sometimes, if they are performing in long grass, or even a crop field, there results a small arena of flattened stems, all pointing in the same direction as if layered by supernatural forces. It was this phenomenon that led to my favourite newspaper headline of all time: ‘Hedgehogs cleared of corn circle dementia’.
The headline also hinted at a mysterious hedgehog behaviour, one so rare that I can only report on other people’s sightings. Why do some hedgehogs sometimes run manically in circles for hours,
pivoting around nothing discernable to the human eye?
All that courtship inevitably generates babies. When I found my first juvenile, a pretty little thing the size of my first, I very quickly remembered what I had been taught five years earlier on my first visit. They may seem small and defenceless, but juvenile hedgehogs have a very effective trick up their sleeves: their new-found spines. And let me tell you, those spines, unblunted by use, are very sharp. Plus a defensive move that is exquisite in its timing: as my bare fingers touched the back of the hoglet, it made a noise like a sneeze and jumped. Now, imagine that is the nose of an inquisitive dog? Quite an effect-ive repellent. So, treat those youngsters with respect.
The fact that there were youngsters indicated that the North Ronaldsay population was still active, but had it managed to maintain the levels that generated such news a few years before? Well, the population had undoubtedly fallen dramatically. Using the same technique as last time, I estimated the total population to be around 105 – I found and marked a total of seventy hedgehogs and had fifty-seven recaptures. An indication that I was getting close to marking most of the population was that, in the last three weeks, of the thirty-five hedgehogs I found, only three were new.
People on the island expressed surprise that there were even this many; in the intervening five years they had drifted out of sight and out of mind. So why were the populations of ground-nesting birds showing no concomitant recovery? Because ecology is never as simple as people would like it to be. The study of individual populations of animals and plants is hard enough, and these populations are never in isolation.
I found evidence that hedgehogs ate the eggs of Arctic terns by feeding quail eggs (a similar size) to hedgehogs – they leave a distinctive pattern in the shell, a small rectangle with the gap between the upper front teeth of the hog being revealed by an uneven entry point. The hedgehog would have then used its tongue to lap up the rich contents. I found tern eggs with the same pattern of damage. This was very different from bird damage, which was either a crush from both sides by a bigger bird, or a stab from one of the smaller ones. I also found the remains of black-headed gull chicks left over by a hedgehog (nothing else would have stayed in the raucous colony to consume the hatchling), though these were probably eaten as carrion.
Was there enough evidence to support the prosecution’s case? The prosecution still maintained that hedgehogs were to blame for the decline in bird breeding success, but my survey of sand eels showed that the amount of food the chicks were getting was far lower than in similar studies in other places. Were the tern chicks starving? Was this because of overfishing of sand eels? The small fish are hoovered from the ocean to be minced and processed into feed for caged fish and pigs. The annual quotas for the sand eel, a species that can make up to 50 per cent of all the fish in the North Sea, are not being met simply because the factory ships cannot find them. For example, in one year the Danish fleet caught only 300,000 tonnes of its 950,000-tonne quota. And the fishing industry complains when the scientists suggest a cut in quotas?
Other theories include evidence that climate change is forcing the plankton on which the sand eels feed to move further north, forcing terns to fly further to find food for their chicks on North Ronaldsay. Or that the warmer surface waters are forcing the sand eels to live deeper, out of reach of the plunging terns.
There were many other impacts on the terns: oystercatchers, starlings and turnstones are all known to take their eggs; cats were seen prowling and vehicles had driven through colonies. Perhaps the black-headed gulls also gave a clue. I visited a large colony on the edge of Hooking Loch, deep in a field of yellow flag irises, helping the birders ring the young. We found about fifty chicks, despite the clamour of angry parents. On a return visit nine days later there was a very different sight: hardly a single live chick was to be found. They were just dead on their nests. If a predator had caused this, then the bodies would have been eaten, and if it was starvation, where there were two chicks, one would have died first. But these all looked to have died at the same time. Had the colony been ravaged by an outbreak of disease? Or perhaps the chicks had been deserted due to the disturbance caused by the invasion of ornithologists.
Whatever the cause of the terns’ failure to breed, it has had a tragic effect. In 2005 Kevin described a ‘silent spring’, as the shrill terns just gave up and left. They have been back each year since, but the chicks that hatch rarely make it to fledging.
The impact of this absence of young is felt by more than just the terns. As Kevin explained, ‘The skuas that used to harass the terns have turned their attention to wader chicks, so there is now a decline in their breeding success as well. The natural system has been knocked out of kilter.’
And there rests the case for the defence. There have been no sightings of hedgehogs on the island for five years, yet the Arctic tern population has not recovered. Was there ever a relationship?
There is a tendency for wildlife management to elicit an uncontrolled jerking of the knee, with the blame landing on the latest or most obvious incomer. While in the case of North Ronaldsay, this seems to have been unjustified, that does not mean hedgehogs are perfect. Sometimes they really are the bad guys.
New Zealand
In retrospect it was utterly crazy, but as the colonialists moved in on the Land of the Long White Cloud, so they sought to make it a little more like home. They needed help acclimatizing to this distant paradise. So they set up the Acclimatization Society – one of many that were set up around the world. Not content with wreaking havoc among the human inhabitants, the colonists also sought to screw up the ecosystem as well.
Maybe I am being unfair. It is only with the gift of hindsight that we can see the dangerously short-sighted nature of passing legislation to encourage the introduction of alien species that would ‘contribute to the pleasure and profit of the inhabitants’. The 1861 Animal Acclimatization Act still has an impact today as conservationists struggle to contain the damage caused by the deliberate and accidental releases: deer, ferrets, goats, pigs, rabbits, rats, stoats, weasels and, of course, hedgehogs have all helped to change the environment.
You can understand why deer and rabbits would be introduced – food, aesthetics, sport – they were utilitarian choices. But why hedgehogs – nocturnal, secretive and not much fun to hunt? And their introduction was no accident. Hedgehogs were a very deliberate introduction. It has all been documented by ecologist Robert Brockie. He has rummaged through the original documentation and charted the official progress of the prickly immigrants.
A pair was received by the Acclimatization Society in 1869; twenty-four hedgehogs were sent in 1871, but only one survived the journey; in 1885, 100 were sent, but only three survived and were released into a Dunedin garden; twelve more were sent in 1892 in exchange for twelve wekas, a flightless bird related to moorhens and coots.
Numbers gradually increased in the Dunedin and Christchurch areas until they were described as ‘extraordinarily abundant’ in 1916.
And now? Well, for good or ill, hedgehogs are an established component of New Zealand’s ecosystem. There is, unsurprisingly, a divergence of views as to the merits of these upstarts. On the one hand there is the undeniable charm of the critters. People like to see them around, and for a long time they have been regarded as perhaps the most benign of the introductions. Even if they have wonky teeth. It seems that the founding fathers (or possibly mothers) of the hedgehog community had a ropey gene that has led to around half of them having missing or abnormal teeth.
Now, however, there are conservationists doing their best to rid parts of New Zealand of these malignant incomers. You see, our dearly beloved friends have a taste for many New Zealand delicacies. And New Zealand is rightly protective of its home-grown beasts. There have been hedgehogs found with rare native beetle remains in their stomachs, including one containing 283 weta legs. Now, I have seen pictures of weta – an amazingly large cricket – and this is testament to the voracity of the he
dgehog’s appetite. They are scary-looking bugs.
Auckland Regional Pest Management Strategy has the hedgehog on its hit list. But there is no plan for a blanket eradication. New Zealand’s conservationists are working on the principle that it is better to protect pockets of what is very special than to try to defend the entire country from a mass of invaders – of which hedgehogs are one of the most benign.
Not everyone in New Zealand has such animosity towards the hedgehogs. Certainly the world would be a poorer place if it were not for Burton Silver’s Bogor cartoons – featuring the eponymous hero, a lone woodsman, who shares a very funny world with a population of snail and marijuana-munching hedgehogs. There is also a chain of bike shops throughout the country called Hedgehog Bikes. And an attempt was made by McGillicuddy’s Serious Party to get a hedgehog elected to Parliament.
New Zealand is not alone in trying to catch the hedgehog vote. Stuart Hughes stood in Devon in 1991 for the Raving Loony Green Giant Party and one of his key manifesto proposals called for the lowering of the buttons at pedestrian crossings to enable hedgehogs to cross safely. I would have voted for him.
Brockie has been keeping an eye on New Zealand’s hedgehogs since the 1950s and has noticed that, rather than sweeping the islands, they have suffered a substantial fall in numbers:
Hedgehog numbers peaked in the 1960s, when I was seeing 40–50 hedgehog corpses per 100 kilometres of road. Now that figure is down to just 1 per 100 kilometres, pretty much the same as in Britain. Nevertheless zealots are killing them here in the sand dunes because they classify them in with rats, stoats and ferrets – the real culprits in the destruction of native fauna.
And not just killing them. Leaping, rather unfortunately, on to the hedgehogs-as-pets bandwagon, in 1994 someone organized 120 hedgehogs to be flown from Rotorua to Miami, where they were refused entry as they had not been checked for TB and were returned. This would have presented a great solution to those in New Zealand trying to rid the islands of the pesky immigrants, but resulted in 120 hedgehogs clocking up so many ‘air miles’ that next time they could afford to go first class.