In Pursuit of Butterflies

by Matthew Oates

  Spring butterflying was restricted largely to rural lanes and National Trust gardens. These are alive with butterflies during good summers, but there were few of the insects around in early 2001. The lanes were full of displaced walkers. I managed to get smuggled in to Strawberry Banks, via a sympathetic owner's land, to keep up my studies of Marsh Fritillary larvae. No grazing animals were present, or likely to be, so there was no possibility of spreading the dreaded virus. Shorn of its dog walkers the Banks was a different place, full of Adders, birds, deer and Foxes. On one occasion a family of Stoats gambolled around me, showing no fear of a human being prepared to be still in nature. I was lucky, for much countryside in northern England remained closed until the end of the summer, including many of the Lake District fells. Nonetheless, the whole experience was severely traumatising, because of the denial of access to the countryside and the sheer lunacy of the situation – but at least I was not a livestock farmer.

  Above all, the foot & mouth saga illustrated the firm grip agriculture has over rural Britain. Agriculture is our default setting for both the countryside and for Nature, and as it intensifies, through technological development, so each generation settles for a more homogeneous countryside and less and less Nature. The main challenge for nature conservation is to reverse that downward spiral.

  Gradually, some worthwhile days came around. An expedition to the Portland quarries on June 17th found that the local race of the Silver-studded Blue had not yet started to emerge. However, the pupae can be found in the galleries of ant nests under flat stones. We found thirteen, in a small area of scree with isolated clumps of the larval foodplant, Bird's-foot Trefoil, and little else. Most were in the galleries of the common black ant Lasius niger, with which the butterfly seems to have a symbiotic relationship. We also found a Chalkhill Blue pupa under a stone. I took it home, but it proved to be parasitised – only, foolishly, I lost the parasite, a tiny wasp, before it could be identified. That's bad natural history.

  Inspired by Ken Willmott's Purple Emperor assembly points on Bookham Common the previous year, I went in search of comparable sheltered high-point territories in Alice Holt Forest, and almost immediately struck gold, or rather Purple. I explored upslope of the huge sallow jungle in Abbots Wood Inclosure, to the crest of the forest. Here, across a lane, stood a small copse of mature oaks, sheltered from westerly winds by tall pines. Nothing. Then a Nuthatch shot out at speed, petrified by something – a male Emperor, in hot pursuit. Seconds later a pair of battling males erupted high above me. I had discovered a male territory every bit as good as those at Bookham. Call it Seven Ways Copse. At least half a dozen males were active in the copse that afternoon. A week later a dozen were flying there, though by then they were ageing, torn and battered. They were fighting to the last, even evicting the resident Spotted Flycatchers. Best of all, I met the owners: ‘Come on in,’ they said, delighted by the prospect of a rare butterfly doing something esoteric on their land. A difficult July was ending.

  August was disappointing, with a scatter of warm days punctuated by spells of heavy rain. In such conditions butterflies do not live long, and whole populations can be blasted away. Somehow that miserable summer managed to generate a plague of Small and Essex skippers on Salisbury Plain, that vast expanse of rough rolling downland preserved as a military training ground. The security men at the check-in point to the MOD's West Down Camp were besieged by these small orange butterflies. It meant nothing to them that there were two highly similar species encrusting the walls of their hut and invading their kitchenette. The things were a darned nuisance. Along the nearby arable field margins every flower head held half a dozen or more, and in areas of tall False Oat-grass and Yorkshire-fog grass on the Plain proper these butterflies truly abounded.

  The initial impact of foot & mouth on our butterflies was that some places became heavily over-grazed and others scarcely grazed or not grazed at all, due to the necessary restrictions on livestock movement. Part of Rodborough Common, called Swellshill Bank, lost its Cowslips when the National Trust's conservation herd of Belted Galloway cattle became impounded there, and heavily over-grazed the slope. The Cowslips have yet to reappear. Swellshill's Duke of Burgundy colony has been a shadow of its former self ever since. For the opposite reason, a large Grayling colony on Selsley Common, across the valley from Rodborough, collapsed in 2001, and never recovered, dying out a few years later. The butterfly had been breeding on small tussocks of fine-leaved grasses along the cattle walkways there. Annual grazing was essential, to maintain these precise breeding conditions, but cattle came on late in the summer of 2001, after foot & mouth restrictions had been lifted, and then made little impact. Grasses grew tall and thick there, accentuated by another wet summer. A disastrous break in continuity of habitat conditions had occurred. This pattern was replicated throughout the countryside.

  The last item to be cast upon the funeral pyres that characterised the landscape of 2001 was MAFF itself. But Phoenix-like, Defra arose from the political flames. Within a decade it had absorbed nature conservation, at least outside of forests. Gradually, I ceased to be a nature conservationist.

  We desperately needed a great summer in 2002 to assuage the traumas of 2001. The year's first butterflying expedition was to a bat hibernation tunnel, where a few Peacocks and Small Tortoiseshells were hanging upside down, like bats, and Herald moths were also hibernating. The year's first butterfly seen on the wing was a Crow Swallowtail (Papilio bianor), flapping haphazardly on a grey late January day below Richmond Hill in south-west London. This dark giant of a butterfly is a common habitué of butterfly houses, and this one must have been an escapee from the nearby butterfly house at Syon Park. With butterflying, always expect the unexpected.

  Winter was mild and wet, and March indifferent, but April was fair and turned things round. Spring butterflies, though, were emerging on the late side. The good April led to a sizeable emergence of Pearl-bordered Fritillaries. Impressive flights of this spirit of the spring were witnessed at Pignal, Ramnor and New Copse inclosures in the central New Forest, in Ashclyst Forest and at Hembury Rough Pastures in Devon, and in the Wyre Forest in the West Midlands. Earlier, I had cycled round large tracts of the New Forest looking for potential habitat, visiting parts of the Forest which had not been assessed for butterflies for many years, though in the past they had been great. Little of potential was found – just pockets of suitable habitat here and there, telling of the glories of yesterday. However, it was good to see the butterfly increasing and expanding in its traditional stronghold to the north-east of Brockenhurst.

  The Pearl-bordered Fritillary's survival at Ashclyst Forest, on the National Trust's Killerton estate just north-east of Exeter, can be attributed to sustained conservation effort. The butterfly had become dependent on a 300-metre-long way-leave carved through broad-leaved woodland to supply electricity to a couple of chocolate box thatched cottages in the forest's centre. Keeping the way-leave Bracken stands in suitable condition for the butterfly has been a major challenge over the years, as not everything that has been done has actually worked. But in 2002, after much encouragement, the butterfly spread out from the way-leave rather spectacularly, to colonise newly opened rides elsewhere in the forest. We had turned the corner. At present, the Pearl-bordered Fritillary is doing well in Ashclyst, though the old way-leave has slowly declined in suitability. The truth is that it is all but impossible to hold vegetation change in check indefinitely and to keep even small, simple sites like the Ashclyst way-leave unchanged. All conservation effort can do in such situations is slow down the rate of change and buy a little precious time, and help butterflies to colonise elsewhere.

  As an add-on to a work-related trip to the Dover cliffs in mid-June, I sneaked a couple of hours in East Blean Woods, near Herne. The Kent Wildlife Trust interpretation board there informed me that these Sweet Chestnut coppice woods hold the largest population of Heath Fritillary in the UK. As founder of the Friends of Bin Combe, the inhospitable combe on the eas
t slope of Dunkery Beacon that holds the strongest of the Exmoor Heath Fritillary colonies, I was deeply affronted by this statement, especially as it was probably true. I walked straight into a thriving colony, in an area where chestnut coppice had recently been cut. Then, after walking down a dark tunnel of tall, overhanging chestnuts, the blinding light of another clearing revealed a second, larger colony. Here, a freshly emerged male was drying his wings, having just emerged from a pupa deep within a tussock of Creeping Soft-grass. A week later I was up on Exmoor, where haughty Bin Combe put on an even more edifying display – even if I did get eaten alive by horse flies and ticks in the process. Some places require you to be faithful to them, none more so than Bin Combe.

  At last we were able to open Collard Hill as an open-access site for the Large Blue. The slope had been grazed to perfection and a seasonal warden was in place, to facilitate visits rather than to police anything – the challenge was to ensure that every visitor saw at least one Large Blue. This was radical, as hitherto the butterfly had, somewhat of necessity, been the domain of a rather private gentlemen's club. Initial visitors to Collard Hill included one determined old boy who had earnestly but fruitlessly sought this butterfly as a young man, and who was about to go into hospital for a double hip replacement. Getting him down the slope, and then back up again, proved decidedly troublesome, but he was a gentleman of considerable determination. It turned out that he had flown fifty bombing missions over Nazi Germany. You don't mess with folk like that. A Large Blue settled to bask right beside him, and in that moment he fulfilled his lifelong ambition to see every species of British butterfly.

  On the last day of June the first Purple Emperor of the year appeared, beating the living daylights out of a Black Hairstreak at the wondrously named Drunkard's Corner, an ancient Blackthorn-lined lane that curls its way round the edge of Bernwood Forest, north-east of Oxford. The Emperor went on to make a disappointing July his own. He was not out in good numbers, in fact this was a decidedly poor year for this and the other high-summer forest species. By mid-July the White Admirals, for example, had been blasted away by foul weather. Only the Ringlet was in good numbers in the woods. But there was a determination about the Emperor's manner that year. An impressive number of male territories were found, in Alice Holt Forest in Hampshire, at Ashtead Common in Surrey, in my old woods back in West Sussex – Southwater Forest – and in Savernake Forest in Wiltshire. An incredibly useful survey technique had been discovered, and not merely by myself and my companion Ashley Whitlock, for Liz Goodyear and Andrew Middleton were making similar discoveries by searching for male territories in Hertfordshire. The one place that refused to reveal its secrets was Bentley Wood in south Wiltshire. This was I R P Heslop's heartland, where he collected most of the 196 Emperors in his collection. Despite having written an appreciative biography of the man whose writings inspired me as a teenager, I struggled to see Emperors in his old woods, and felt that I was intruding and unwelcome there – even when accompanied by his youngest daughter, Jane Murray. My diary for July 11th includes the curious comment: I got the feeling that even now IRPH resents people Emperoring in his woods. Somehow, people's experiences, memories and values become part of places with which they are intimately entwined – I am struggling to comprehend this, the collective memory of place.

  Purple Emperor numbers in the little copse I had discovered on the edge of Alice Holt Forest the previous season, Seven Ways Copse, were at best half what they had been in 2001. One afternoon was particularly quiet: a female had appeared and a whole bevy of males had shot off after her. One by one they returned. One ragged male, with a badly pecked left forewing, perched high up on a partially shaded Beech branch, intermittently launching himself against passing birds and insects. The diary recalls that Pecked Left Forewing was taken by a Spotted Flycatcher over the Beech. They ganged up on him: he attacked one but was taken by its partner from behind. A couple of shredded wings softly spiralled through dappled sunlight to the ground. The 2002 Purple Emperor season had ended.

  August was quite a reasonable month. At last butterflies started to appear on garden Buddleias. The two cabbage whites, in particular, were in goodly numbers, as they tend to be after a couple of poor summers. The month even brought an influx of Clouded Yellows. Within a couple of weeks they were widespread in southern Britain, and made the most of the sunniest September since 1991. It was as if the year was trying to turn things round, and to set up its successor as a proper butterfly season.

  Drunkard's Corner

  Here is a place outside of ordered time,

  Where the same cows graze the clay mead,

  And light spindles soft along a stippled lane

  As if, perhaps, it has always rested so,

  Filtered by ever-ancient blackthorn boughs

  That tunnel haphazard over age itself,

  Through summer, once more, and on again.

  I cannot say how this lonely place

  Took its name, a name of man,

  For no man comes here, drunk or not,

  No singer staggers along the ruts,

  In time of slipping mud or kicking dust,

  On Midsummer or on any other eve.

  One act, or one man, long ago aroused this name,

  And so it has ever rested so, and ever always will.

  But here, still now, amongst the brambled tangles

  A whitethroat scratches out his rusty song,

  While an ancient peeling notice reads and pleads:

  ‘Please close the gate’, the gate that leads to time.

  23 The Emperor's return

  The next year, 2003, did not start well, with widespread flooding followed by lengthy cold spells that brought the first snow in southern England for a couple of winters. February stabilised things, steadily drying out the land. The first butterflies of the year took to the air on February 23rd, when my family and I were attending an anti-war demonstration at Fairford, Gloucestershire, in my case under the metaphysical banner of Butterflies for Peace. The diary records that Rooks were building, cock Greenfinches displaying and buds swelling. Best of all, a gloriously eccentric middle-aged lady, dressed in a bright pink nylon fairy outfit, complete with wings and wand, was arrested by a butch-looking police lady for attempting to scale the airbase fence. Parliament had spent seven hours debating whether to go to war in Iraq, compared to 700 debating the future of hunting.

  March was sublime, dominated by anticyclones stationed over Scandinavia. It was the sunniest March since 1907. However, as so often happens in early spring, a chilly east wind developed, which kept day temperatures a little too cool for butterfly activity. It was, though, ideal caterpillar-hunting weather. At Strawberry Banks, 27 larval webs of Marsh Fritillary were closely studied (containing some 1500 larvae). These began to change their skins mid-month, a week earlier than in 2002. Thirteen of these webs proved to be free of parasitic wasps, and only six seemed to hold significant parasite numbers. A reasonable emergence of Marsh Fritillary butterflies was on the cards, weather permitting.

  But the month belonged to Pearl-bordered Fritillary larvae. The first was found on March 2nd, in Cirencester Park Woods, basking in gentle sunshine on a dead bramble leaf. Later, on March 29th, one of my more bizarre butterflying experiences (or rather caterpillaring experiences) occurred, again in Cirencester Park Woods. Just after I had located three Pearl-bordered Fritillary larvae in a pocket of tree leaf litter and violets, the Vale of the White Horse Hunt appeared and utterly surrounded me. Diary: This I chose to ignore, and they obliged me by returning the compliment. I had nothing polite to say to them. The message is simple: Carry on caterpillaring.

  Expeditions in search of Pearl-bordered Fritillary larvae also took place in Wyre Forest on the Shropshire/Worcestershire border, in Bentley Wood in south Wiltshire, in worked Hazel coppice woods near Stockbridge in Hampshire, and in the heartland of all butterflying, the New Forest. The Wyre was particularly exciting. There the mission was to determine where the butterfly was
actually breeding – no easy task in a vast forest. Butterfly breeding grounds can be decidedly small, localised, discrete and short-lived, and do not necessarily correlate with where the adult butterflies are seen. Breeding can be restricted to tiny pockets scattered amongst an ocean of unsuitable terrain. That is very much the case in the Wyre, where Pearl-bordered Fritillary butterflies are seen in numbers in several places where they cannot possibly be breeding. The narrow linear meadows bordering the delightful Dowles Brook in Wyre are great for the adults, being sunny, sheltered, and rich in nectar-bearing flowers – only the violets on which this butterfly breeds are all but absent. Much of the Wyre is too acidic for the violets, though suitable violet habitat occurs in minute pockets. Somehow, the canny females find those isolated hot spots. Worse, the females have to find spots that are going to be suitable for the tiny baby larvae in early summer and the following spring, after hibernation.

  In early April the Pearl-bordered Fritillary larvae wandered off to pupate. In Cirencester Park Woods, the adults started to emerge on April 22nd, with a bang. There was clearly going to be a mighty emergence. The Duke of Burgundy and his arch enemy the Dingy Skipper appeared early at Rodborough Common near Stroud, on April 15th, and immediately began squabbling. Grizzled Skipper was out nearby even earlier, on April 7th. More significantly, an influx of Painted Ladies took place on March 12th. A good butterfly season was developing, but would the weather hold?

  April ended poorly, and then:

  Diary, monthly summary: May was a disgrace and undid the good work done by March and April. Eight days were spitefully vile. There was a spell of fine weather from the 4th to the 9th inclusive, when it seemed a fine month was developing, especially as the Painted Lady appeared in good numbers. [I saw 34 in Ashclyst Forest, East Devon, on the 6th, and 28 in the New Forest on the 7th.] However, it then lapsed into the odious pattern of clearing for the night and clouding up for the day. A horrid wet seven days developed, which effectively blasted the spring butterflies away, Pearl-bordered Fritillary included. The month ended well in the east of England.