In Pursuit of Butterflies

by Matthew Oates

  A group of twenty invited guests gathered around the table, then pulled back to await the arrival of His Imperial Majesty. One male instantly appeared, only to land on the table cloth. Then one of the most unwelcome banks of cloud ever to irritate the blessed realm of Albion appeared, and most butterflies stopped flying. In order to give the honoured guests something to do we picked the whole caboodle up, pickled mudfish and all, and carted it 300 metres up the ride. Eventually, the sun reappeared and some rather sulky Emperors deigned to visit the table, effectively for afternoon tea, along with a couple of Commas and a White Admiral, two other butterflies with appallingly bad taste. For the record, pickled mudfish and Big Cock shrimp paste were clear winners, and during the day I noted some fifty male Purple Emperors and a lone female. For much of the day Margaret Thatcher's voice had been echoing in my head, in speech-making mode, saying: ‘When it comes to eccentricity Britain still has what it takes!’

  The following day, the 2009 Ashes series began, with England reaching 335–7 at Cardiff. Consequently, the jet stream jumped south, and the weather collapsed. On Friday the 10th, two BBC film crews returned to finish off The Emperor's Breakfast and to film Hulme and Oates's annual contest to find out which one of them could bait the most Emperors down. The competition boiled down to Big Cock brand versus a particularly vile Vietnamese shrimp paste called Hau Loc, which was subsequently banned by the EU as being unfit for consumption, human or otherwise. The contest ended in a draw, largely because both participants lost count of how many Emperors had descended to their respective baits. Australia declared at 674–6 and reduced England to 20–2. More significantly, the first of the home-grown brood of Painted Ladies appeared, just overlapping with the last of their pilgrim fathers. Eventually the first Test ended in a remarkable draw, with a last-wicket stand saving England from ignominious defeat. This drama was dutifully followed in Savernake Forest, in deepest Wiltshire.

  Then something terrible happened to the 2009 Purple Emperors: a vicious autumn gale came over during the night, when they were at roost high in the oak crowns. It was St Swithun's Day, of course, July 15th. Numbers in Alice Holt halved overnight. It was time to move on, to survey the developing Emperor grounds in the re-wilding lands of the Knepp Castle Estate in West Sussex, just south of my old heartland woods. Here, visionary landowner Charlie Burrell is ‘re-wilding’ some 1300 hectares (3200 acres) of low-grade agricultural land on heavy Wealden Clay, inspired by the great Dutch ecologist Frans Vera's theory of naturalistic grazing systems. Many of the fields taken out of arable production some ten years previously and allowed to re-wild, under a low-density grazing regime, had sown themselves with myriad sallow saplings. In mid-July 2009 these fields held huge stands of young hybrid sallow whips, 2–3 metres tall. It soon became clear that the Emperor, supposedly the archetypal high-forest insect, had moved in to colonise. He had probably always had some exiguous form of existence there, perhaps moving in during fine summers and disappearing during sequences of poor summers, breeding intermittently on a scatter of old sallows growing in the green lanes and lags (a Sussex word for a shallow damp combe). Other butterflies abounded, meadowland species like Meadow Brown, Gatekeeper, Ringlet, Marbled White, Small and Essex skippers, and Common Blue. A mighty hatch of Small Tortoiseshell was taking place. Missing, though, were the anticipated hordes of freshly emerged, British-passport Painted Ladies, emerging off the extensive drifts of Creeping Thistles. Only two were seen.

  I spent the night as a house guest at Knepp Castle, a crenellated castle designed by John Nash. From a sunken bath in a bathroom the size of a small universe I watched a cataclysmic thunderstorm raging over the park outside, as the summer of 2009 imploded. I had come a long way from a leaky tent in the nearby woods, yet my heart had not travelled far. Knepp Castle is lived in, as a family home, and consequently lives. It is the antithesis of a National Trust stately home. Inside the iron-studded oak front door lies a motley array of muddied Wellington boots, wet weather gear, sunhats, fishing rods, walking sticks and umbrellas – all the things house guests might need, for grand houses were built for hospitality. Inside, bath water reverberates along miles of ancient plumbing, footsteps run up and down stairs, doors slam, unseen things crepitate, laughter echoes down smiling corridors, and the entire establishment is run by an ancient basset hound called Spider – a canine version of Lord Emsworth's accommodating butler, Beach.

  The Emperor was winding down, the Painted Lady was failing to wind up, the weather was at best indifferent, but it became clear that the Purple Emperor had laid an enormous number of eggs. I searched for eggs when the sun was not shining, which was most of the time. When they hatched the search continued, for the minute larvae hiding in curled leaf tips on shady sallow sprays. In all, still on sabbatical, I searched for Emperor eggs and larvae in ten counties. There was little else to do: July had fallen spectacularly from grace and had become very wet in most places. The last Emperor of the year was seen in Savernake Forest on August 7th, my birthday; a male so worn, torn and faded that I mistook him for an ancient Painted Lady up in the Beech canopy. He was fighting to the bitter end, but the lone Large White he rose to intercept chose to ignore him. In the evening I gave a poetry recital to the Malmesbury Festival – always do something new and different on your birthday. The only blemish on the day was the England captain winning the toss at Headingley in classic seam-bowling conditions, and unwisely deciding to bat. England were shot out for 102.

  Eyestrain kicked in, as it will if you spend hour after hour hunting for butterfly eggs and tiny larvae on myriad leaves. It could not have been done without the accompaniment of a riveting Ashes series. One can do So Much under the influence of Test Match Special. Most of the time I was alone, but Dennis Dell, Ken Willmott and other like minds joined in periodically. Most notable here was an Abyssinian cat who spent a sultry afternoon helping to find larvae on Selborne Common, clowning about in sallow trees with me (much to the surprise of a passing dog walker, who had blundered into an anamorphic world) and at one point catching a Bank Vole. Saying farewell to her was difficult. Every now and then we fall in love – with individuals of a different species.

  The Brown Hairstreak provided a welcome distraction, at least during the early mornings when this generally indolent butterfly is actually active. On the morning of August 9th I counted 44 in three heady hours and witnessed a pairing, on rough MOD land near Shipton Bellinger on the Hampshire/Wiltshire border. That tally remains the most of that elusive species I have seen in a day. They became active that morning at 8.45 and, as usual, were quiescent by high noon. Most were seen on or even within the scatter of Ash trees that protrude above the thickets that blanket much of the landscape there. Just before 10 am a female flew low across a field and rose up into a row of tall Ash trees occupied by half a dozen males. She was instantly accosted by a male. Within half a minute they were mating, motionless and wings closed, on the underside of an Ash leaf some 4 metres up. Their coitus lasted 40 minutes before, without any ceremony, they parted and flew their separate airways.

  Another search of Knepp Castle Estate's re-wilding lands revealed a sizeable population of Brown Hairstreak, when the sun shone, and, when it didn't, Purple Emperor breeding at low density throughout the developing sallow jungles. And at last the long-awaited explosion of freshly emerged Painted Ladies took place, but this was way short of the billion predicted to emerge in early August, and it was now mid-August. Other people certainly witnessed some mass emergences, locally, including Neil Hulme on the South Downs a short flight away from Knepp, but my fate was not to see more than around fifty anywhere in a day. I should have visited the woods less and visited the downs more, perhaps, but my heart was in the woods; or rather, it was in the forest, for Savernake steadily absorbed me. Gradually, I retreated there, systematically surveying the entire 1000-hectare forest and many of its outliers for sallows, and for Emperor larvae. This work continued deep into the autumn. Even Neil Hulme's discovery of a breeding colony of the Que
en of Spain Fritillary, one of the rarest of our vagrant butterflies, near Chichester in West Sussex, could not lure me away from Savernake's cathedral Beech trees, hidden Bracken glades and immense sense of history. It had become integral to my life, a deep heartland had been established.

  The summer was ageing. Soon it would be time to end my sabbatical and return to normality, only normality had flown out of the window as the organisation was in the throes of another massive though well-intentioned restructuring programme. In big organisations restructuring can become endemic and cyclical, like myxomatosis in Rabbit populations. There seems to be some deep desire within some of us to seek perfection in systems. My last month of freedom passed in increasing dread – of having to retreat from the real world of Nature back into the world of business systems. The message from a sabbatical is simple: stay healthy, stay sane, retire at the earliest opportunity – and let your life's real ministry commence. We spend too much time in the unreal world of systems. As the American poet-ecologist Gary Snyder puts it, Nature is not a place to visit, it is home. I had just spent three months at home. We spend so little time there.

  Somehow I was at last reaching a fair understanding of the sort of situations the Purple Emperor breeds in, and his breeding requirements are most exacting. It became clear that eggs are laid in quite heavy shade, because leaves in exposed situations grow coarse and thick, and are presumably unsuitable for tiny young larvae. In shade, sallow leaves that are mid-green in colour, soft in feel and dull in finish are selected. Find mid-green, soft, matt leaves and you will find the Emperor, at least after good egg-lay seasons. Old ‘BB’ knew this, and he called them ‘apple leaves’. Those subjective characteristics are associated with leaf thickness, which can be measured. Sallow taxonomy proved to be a red herring, for the vast majority of sallows assessed proved to be hybrids, and highly variable hybrids at that. Everything that could readily be measured was measured, though the Emperor does not really do Science; everything else was estimated, as consistently as possible. It felt that, after many years stuck in a Western Front-type situation, I had finally broken through with the Emperor. Time would tell, though, whether the breakthrough was actual, or a phantom.

  All told, 181 eggs and larvae were found, 141 of them in Savernake. By Emperor standards, that is one heck of a sample size. Many in Savernake were marked out for following through the winter and into the following spring. Perhaps the highlight, though, was finding a larva at the Clacket Lane Service Station on the M25 (anticlockwise), in full view of a couple of lethargic police officers, sipping coffee in their vehicle. They had accrued a few years’ service between them and had seen it all. ‘Purple Emperor?’ one of them inquired through a wound-down window. I nodded. Miraculously, that caterpillar survived to be photographed the following May.

  One by one the surviving Savernake caterpillars entered hibernation, the first on October 23rd and the last on November 8th. All told, 38 were found in hibernation there, out of some 67 autumn larvae that had been followed closely. That is one mighty sample, and enabled close study of the previously unstudied five-month hibernation period. Thirty of the 38 were aligned on stems next to buds, five in damaged areas in bark and three in twig forks. All matched the colour of the substrate they were on. They had journeyed distances of up to 3.5 metres to find a suitable hibernation spot – not bad for an animal less than a centimetre long. Perhaps some of the lost legions had travelled up and away, out of searching range. Whatever mistakes you make in life, please do not underestimate a caterpillar.

  And as for the Painted Ladies? They emerged in good numbers in some places, especially close to the south coast, but their aspirations were limited, as if some mysterious power had thwarted them. As in August 1996, this home-grown brood did not pair up and lay eggs. They hung around in gardens and other flowery places, sipping nectar and behaving like tame garden butterflies feeding up prior to hibernation or death. In late August and throughout September they were seen drifting out across the Channel, heading south, in ones and twos. Perhaps they had taken on and been bettered by a greater butterfly? Amazingly, though, by means of an entomological radar, scientists from the Rothamsted Research Institute proved that most journeyed south at incredibly high altitudes, taking advantage of high-level winds more than 350 metres up, the insect equivalent of the Mile High Club. Perhaps Psyche herself had dismissed them?

  28 Adventures with caterpillars

  Finally, I had broken winter's grip. By following Purple Emperor larvae in the wild on their journey from autumn into spring, I had at last made butterflying an all-year-round activity, and winter had become a mere phantom. Hairstreak eggs, the staple winter activity of many butterflyers, only take you so far. Marsh Fritillary larvae, which appear in late winter, had helped, by shortening the close season. But there was a need to venture deeper, and the Emperor does go deeper; indeed, it reaches the parts other butterflies cannot reach.

  Down in Savernake Forest, hibernating Purple Emperor larvae were slowly disappearing. Three vanished without trace during December, presumably to avian predation. Interestingly, though, none disappeared during January 2010, which was cold and snowy with much lingering frost. There was a ten-day spell of lying snow, which may well have protected the hibernating larvae, and may also have driven hungry birds, such as tits, out of the forest, to bird feeders in the surrounding gardens. However, although February was also cold the precipitation that fell down south occurred mostly as rain, cold bitter winter rain. A little further north much of this fell as snow. During February, unprotected by snow or ice, nine more Purple Emperor larvae vanished to assumed or actual predation, a worrying number, as it meant that twelve of the original 38 had now vanished. Worse, a butterfly collector – for such people still exist – had followed me on my rounds and had callously snipped off five hibernating larvae. Doubtless he (it would not have been a she) had been following my postings on the Purple Emperor Blog. The secateur cuts were all too obvious, as had been my location markers. Sadly, the Emperor remains highly collectable, and will remain so for so long as he is regarded, wrongly, as a great rarity.

  A sequence of broadcasts on Radio 4's On The Move programme followed the fate of the monitored Emperor caterpillars. In the interests of storytelling, and against the strictures of science, the participant caterpillars had all been named after great poets of the English language. This proved unduly stressful, not least when the mighty T S Eliot vanished without trace, though the loss of a platoon of Great War poets was perhaps predictable. The real horror was when Coleridge himself was stolen, snipped off in his slumbers (I immediately upgraded a replacement caterpillar, originally named after his daughter, Sara, and can announce that Coleridge successfully pupated). The truth is that I had no idea what to expect in terms of winter mortality, as no comparable studies of similarly behaving larvae had been attempted in Britain. The Emperor was breaking new ground. At the end of a long winter only thirteen of the 33 followed larvae (excluding five which had been collected) survived into the spring, 20 having succumbed to probable predation, most likely by tits.

  March began gloriously, luring out the first butterflies, then fell back into deep midwinter mode. The first fourteen nights brought heavy frosts, often as low as minus 7 degrees Celsius in central southern England. The month then ended cold and wet, with heavy snow up north. Winter would not let go. It became apparent, though, that Marsh Fritillary larvae were in excellent numbers at Strawberry Banks, near Stroud, doubtless owing to good weather when the females were laying eggs during the early summer of 2009, in Painted Lady time. Seventy-four webs of the gregarious larvae were found, containing in the region of 5600 caterpillars. Better still, the parasite load, as measured at the fourth skin change, appeared to be insignificant. If the weather was fine in early summer the Marsh Fritillary would abound here.

  Our relationships with places are complex in the extreme. On March 14th I found myself travelling, unplanned, to Alice Holt Forest. The place seemed to be calling me. It felt as th
ough something was wrong there. I arrived in the Straits Inclosure to find that most of the sallow trees growing along the main ride there had just been felled. Only 61 remained – out of the 510 I had counted, sexed and identified into taxa the previous June. I managed to rescue a lone Purple Emperor caterpillar found crawling over the felled corpses. The news got out amongst the butterflying fellowship and a mighty row ensued, which I ended up having to pacify. What the Forestry Commission had failed to comprehend is that to the hundreds of naturalists who visit the place during the high summer period, it is not a wood, let alone a standing cash crop, but a forest cathedral. A year later most of the complainers were up in arms defending the Forestry Commission against proposals made by Caroline Spellman, Minister of the Environment, to sell off the state forests. I was not amongst their number.

  April came in on the back of a cold, late winter. Primroses and daffodils only got going properly at the start of the month, but after a poor and wet beginning April was dry and sunny, with a warm ending. Somehow, the spring butterflies were emerging on time or even a little early. My first Orange-tip was duly noted:

  Diary, April 10th 2010: He ascended from a patch of Wood Anemone, flew through a shaft of sunlight and bumbled happily past me. He then spent 10 minutes visiting Celandines and more Wood Anemones before I lost him.

  The world was slowly righting itself. On the 17th the first Gloucestershire Duke of Burgundy of the year appeared. Diary: She flew up over me as I was kneeling down to admire her, and vanished – the minx. The Painted Lady even put in an appearance, on the 24th. Apparently they had been massing again in Morocco and southern Spain. Bring them on! I wrote, but sensed that entomological lightning would not strike twice, at least not in consecutive years. Perhaps they were scared of the Emperors? At the end of the month the first Pearl-bordered Fritillaries appeared in Cirencester Park Woods, and the thirteen surviving Purple Emperor larvae in Savernake were at last feeding properly.