In Pursuit of Butterflies

by Matthew Oates

  Miraculously, after eight rotten days May materialised into the best since 1992, as high-pressure systems bubbled up nicely. Pearl-bordered Fritillaries made the most of it. Their numbers were not high, as their larvae had endured a difficult March and April, but at least eight colonies were present in Cirencester Park Woods and good flights were witnessed at Hembury on south Dartmoor, Ashclyst Forest in east Devon, Cwm Soden near New Quay on the Ceredigion coast and in Parkhill and Pignall inclosures in the New Forest near Brockenhurst. May 2004 belonged essentially to this fritillary. With butterflying, it often happens that a single species lays claim to a particular month.

  June actually behaved itself, providing a number of fine sunny days without ever developing into a great summer month. It started on the Isle of Wight, where the Glanville Fritillary was having a bumper year, not least at Compton Chine, where 266 were counted in a 20-minute circuit of the main flight area, at the foot of the flight of wooden steps which have to be repaired at the end of each winter. The old butterfly collectors would have liked this emergence, for several aberrations were noted, mainly with reduced black vein markings on the wing uppersides, and a blurring of markings on the undersides (probably ab. uhryki). The butterflies had spread well the previous May, to form or strengthen colonies all along the nearby downs, breeding in areas where gorse had been either mown or burnt. The flora, and its associated insects, relishes the windows of opportunities these actions provide.

  Not too many British butterfly enthusiasts have seen Large Blue, Black Hairstreak and Swallowtail on three successive days, plus Wood White, Duke of Burgundy, Small Blue and the first Meadow Brown of the year. But the Large Blue began to emerge at Daneway Banks in the Cotswolds on June 5th, along with the first Meadow Brown; Black Hairstreaks and Wood Whites were flying at Whitecross Green Wood in Buckinghamshire on the 6th, and on the 7th I found myself in the Norfolk Broads, where Swallowtails were emerging strongly. Catfield Fen put on a terrific show of magnificent Swallowtails – 34 sightings in a couple of hours along the path bordering the Butterfly Conservation reserve, mainly of males feeding on early bramble flowers. But the following day I encountered the dark side of the Swallowtail. After a meeting in an anaerobic office in Norwich, I escaped to a site on the edge of Hickling Broad that had been highly recommended. The diary account explains all:

  Diary, June 8th 2004: The site was thickly fringed by dense, dangerously wet carr with the highest density of mosquitoes I've ever encountered. They attacked me viciously as soon as I hopped over the gate. After failing to get to the recommended open area, as the ground was too wet and clearly too dangerous for lone working, I retreated to an open glade. Here Milk-parsley abounded, amongst low reed and sedge, but I failed to see a single Swallowtail or find any eggs.

  Worse:

  I ended up in an oxygen-free room in a rotten B&B next to an all-night-lorry road. Some of the mosquito bites became infected and remained troublesome until mid-July, and I swear they attracted more mosquitoes.

  This was one of only two occasions when I felt in danger whilst butterflying in this country, and dipped out on health and safety grounds. The other was a manic attempt to flush up Large Heaths on Rannoch Moor in the Highlands, in precipitous rain.

  Precipitous rain dominated July 2004 as well, a month that commenced with a gale and deteriorated from there. The Purple Emperor and White Admiral were effectively written off, though Silver-washed Fritillary flourished, as it seems better equipped to cope with bad weather. The Emperor season had started ominously, on Midsummer Day. I was attending a meeting, deep underground in Defra HQ, Horseferry Road, in Westminster. The diary relates: I was captive in another world, and all the time the iris were calling for me, I could feel them emerging. They were too – the text message came in as I was travelling home. Fred and George, the two Purple Emperors that I had found as larvae the previous late summer, were dutifully returned to their place of origin, only they had transmogrified into Frederica and Georgina, big girls too. They may not have fared at all well, for deluge after deluge fell in the hours and days after their release. At one point I walked out of the Purple Emperor season and returned back to work. Things were that desperate. Curiously, though, the Holly Blue made one of its periodic bids for freedom, appearing in surprisingly good numbers, only to be blasted to kingdom come. The diary concludes: This goes down as The Lost July.

  August had to save the show, and some butterfly had to redeem the year, by claiming it as its own. The answer came on August 1st, a wonderful hot sunny day after a clear night with a harvest moon. I arrived at Whitecross Green Wood, in the old Bernwood Forest woodland complex near Oxford, at 10.30, later than intended, and saw 20 Brown Hairstreaks, without making much effort. Sixteen of them were on, or even in, the Ash trees that are scattered throughout this nature reserve, which the Forestry Commission started to coniferise before selling it off to the county wildlife trust. Sixteen represented a good start to the Brown Hairstreak season. Despite a dismally wet August, memorable for the Boscastle floods in which TV news showed four-wheel-drive vehicles being washed out to sea, the Brown Hairstreak did well. The eggs had hatched late, so young larvae had been spared the worst of the spring weather; then larval development was blessed by fine weather during May and June, and the insects were safely inside their pupal cases by the time the July monsoons arrived. This elusive butterfly was equally impressive in north Wiltshire, at Noar Hill in Hampshire, and near Tidworth on the Hampshire/Wiltshire border. There, in early September I counted 36 apparent individuals in a day, the second highest day tally I have ever made – and I would have seen more had I started earlier, before 9 am.

  The Brown Hairstreak has much in common with the Purple Emperor, occurring at low population density and being a canopy-dwelling butterfly which is active only intermittently. Above all, it is both elusive and evasive, and can be downright infuriating, not least because it takes days off. Unlike His Imperial Majesty it does visit flowers – mainly brambles, but also Angelica, Hemp Agrimony and ragworts, and the males are only modestly belligerent, and then only during a happy hour of indulgence in the early morning, as the day warms up. Butterfly people who work Purple Emperors tend to gravitate to Brown Hairstreaks as the Emperor season ends, perhaps because Brown Hairstreaking actually generates worse eye strain and neck ache, and because the Hairstreak is almost as enigmatic. After having been grossly neglected throughout the long and glorious history of entomology in this country the Brown Hairstreak suddenly became popular during the early noughties – and in 2013 it became only the second butterfly to gain its own website and blog, after the Purple Emperor. The season ended with a late flush of Clouded Yellows and a modest show of Holly Blues, including a partial third brood that lasted into mid-November.

  My last butterflying expedition of 2004 was opportunistic and spontaneous. In early December, whilst standing around in a circle with thirty colleagues, discussing a coastal retreat scheme on the Essex marshes, I started looking for the opaque lozenge-shaped eggs of the Essex Skipper in grass tussocks. No one noticed, for nature conservationists enter some bizarre Buddhist state whilst standing around in circles in the rain, so I carried on, and became absorbed. A good two dozen of these overwintering eggs were found, in strings of three, four or five, several centimetres above ground level in the sheaths of old Cock's-foot and Sea Couch flower stalks. Always go butterflying, it helps. Perhaps the collective noun for an encirclement of nature conservationists should be ‘a waffle’?

  Winter had to make up for the lack of a proper summer. It seemed that the seasons were merging into one. The winter of 2004/05 was devoted to searching for Brown Hairstreak eggs in the hedges and thickets of the Oxford Clay vale north-west of Swindon. A small group of us systematically surveyed a large chunk of what was formerly known as the Forest of Braydon. Time ago, Braydon consisted of rough boggy pastures belonging to small dairy and stock farms, interspersed by woods and copses of oak and Hazel. Edward Thomas knew it well as a youth, having relatives in S
windon, but it is now scarcely recognisable as the rural idyll he describes in the second chapter of his first piece of rural prose, The Woodland Life. That chapter is entitled ‘Lydiard Tregose’, but the parish has largely been absorbed within the urban sprawl of Swindon. Through sheer tenacity the Brown Hairstreak has survived, mainly around a scatter of old ridge and furrow meadows.

  The butterfly's distinctive white eggs are relatively easy to find during the winter, and can be easier to spot than the adult butterflies. Most are laid in forks on Blackthorn stems. But the females strongly favour young, dynamic growth, especially along advancing scrub edges. Also, as I had discovered in Hampshire in 1982, grey-stemmed growth is strongly preferred to the shiny red growth that occurs in many places, and browsed growth is largely avoided. The Brown Hairstreak should be a moderately common butterfly in landscapes where Blackthorn hedges abound, and has no business being a national rarity. However, scrub is deeply resented in today's countryside, particularly invading scrub edges, even on many nature reserves, and the vast majority of eggs laid on hedges are destroyed by hedge cutting. The potential for bringing this butterfly back is enormous, given more sympathetic hedge management and a more positive attitude to scrub as a habitat, not least because the butterfly appears to be a great wanderer.

  Today, groups of devotees survey and monitor Brown Hairstreak eggs virtually throughout the butterfly's range. It is the staple winter activity of several of the Butterfly Conservation regional and county branches. Participants are known to carry on, regardless, in heavy rain, or when the Blackthorn is white with hoar frost, or even when snow is falling. On occasions some have been known to carry on after dark, to finish a length of hedge by torchlight or even by car headlights. Many a dog walker has been alarmed by this activity. One group of egg hunters was accused of setting snares, another of stealing fairies.

  Early in January 2005 Butterfly Conservation HQ arranged a mini conference on the ecology and conservation of the Brown Hairstreak at Brinkworth, a hilltop settlement village in the Forest of Braydon. This was the society at its very best, with fifty or so friends of the Brown Hairstreak meeting to share experiences, knowledge and ideas. People had travelled from as far away as Pembrokeshire and Lincolnshire. The amount of effort being put into unravelling the mysteries of this enigmatic butterfly, and determining its conservation needs, was hugely impressive. Despite the fact that Professor Jeremy Thomas had conducted invaluable research into this insect, as part of his PhD, a vast amount of new knowledge had been determined. The butterfly has become far better known, both within and outside conservation circles. It now features intermittently as a local speciality in The Archers on Radio 4.

  During my perambulations in the Forest of Braydon early in 2005 I discovered something quite remarkable, a derelict farm, of some 80 ha (200 acres). Rundown farms were moderately commonplace in the nether regions of Somerset during my childhood, but I had not encountered one for decades. This example was all the more remarkable because the fields were unimproved ridge-and-furrow meadows, which had been spared modern fertilisers and sprays. The holding had been a small stock farm, where a few beef cattle were raised. Early in 2005 the fields consisted of dense mats of grasses, with huge tussocks of Cock's-foot and Tufted Hair-grass and a thick layer of dead litter. They were so difficult to walk through that the village dog walkers had kept away. It was forsaken, apart from by Nature. The smaller herbs were of course heavily suppressed, though taller herbs such as Common Sorrel, Betony, Devil's-bit Scabious, Marsh Thistle and Saw-wort were prominent enough. Now that's Marsh Fritillary country. Sure enough, larval searches in late winter revealed a couple of sizeable colonies – just as the butterfly was feared to have died out in the Forest of Braydon. A few years later, the farm was sold and brought back into productive agriculture.

  The spring of 2005 came and went. I rather missed it, as my mother died in late March. She had supported me through thick and thin. A male Brimstone flew along over her coffin as it was being carried up to the church. So that was her butterfly! Butterflies have the remarkable habit of appearing at times of bereavement.

  May started and ended well, but sandwiched in between were three dire weeks – especially in Gloucestershire, which seems to suffer the worst of any adverse spring weather. In Cirencester Park Woods, Pearl-bordered Fritillary colonies at the northern, higher end of the woods emerge a week later than those at the southern, lower end. In 2005 the southern colonies were blasted away by lousy weather but those in the north emerged as the weather improved, and fared well. Never put your eggs in one basket, particularly if you're a butterfly.

  June was also a major disappointment. The first six days were despicable, and effectively wrote off the spring-flying butterflies, again. Some short spells of hot sunny weather followed, though they were ended by pulses of bad weather. Violent thunderstorms on Midsummer Day caused a vast amount of damage, and not merely to butterfly populations: the first day of the Glastonbury Festival was wakened at dawn by a deluge that deposited 5 centimetres of rain there, and washed tents away. Somehow, I managed a sublime three-day expedition to the Norfolk Broads, where the Swallowtail was at peak season, seemingly in good numbers. The highlight was the discovery of a colony on the eastern edge of Duck Broad, on the western edge of the National Trust's Heigham Holmes holding. From the raised bank here one could watch eight or more males patrolling over the reed beds that fringe the open water. They were, of course, utterly inapproachable, without a boat.

  The diary states that July started with A thoroughly depressing day, of endless drizzle, spent vacating our beloved office in happy Cirencester. We were being moved to a new open-plan office in Swindon. The damage this did to my personal relationship with Nature was immense, and not simply because my job changed and I became more office-bound – crucially, lunch-hour butterflying ceased, as there was nowhere nearby worth visiting. The diary entry concludes: This whole year is in free-fall. Only one thing can save it, the iris…

  The Emperor season started promisingly. On Saturday July 2nd, as I entered the Straits Inclosure in Alice Holt Forest, the Aussie skipper was out to the first ball bowled. Another Australian wicket fell as I entered Goose Green Inclosure, where the Emperor season exploded with a trio of battling males. This promising start, however, heralded only a modest Emperor season. Seven Ways again provided a few days’ shelter from the storm, and Alice Holt some rewarding days surveying for male territories along the ridge that runs lengthways through the forest, but Seven Ways had been put up for sale and was emptying itself, with a view to relocating to California. The message I was handed by the Sufi community was clear, and hugely challenging: Develop the spiritual side of butterflying. This message was not enthusiastically received. ‘Not me,’ I thought, ‘I'm irresponsible.’ As I was leaving I picked a pristine Jay's feather out of a flowerbed.

  As the door to Seven Ways Copse was closing, another door was opening elsewhere.

  Diary, July 16th 2005: Fermyn Woods, Northamptonshire. Previously visited briefly late in the great 2003 Emperor season. Today I saw one of the best flights of Purple Emperor I've ever seen – and the locals (Doug Goddard & Co.) say that this is very much an average iris season here! I was absolutely right in 2003: this is the best iris wood I've seen since Straits Inclosure in the mid-1970s. It must support the largest population in the country, by a long way. The reason is obvious: the quality and quantity of sallow is greater than elsewhere, seemingly as a standard feature of clearings and rides on Boulder Clay. Even fellings from conifer plantations here are choked with sallows. All told, I saw about 32 males and 10 distinct females.

  Another heartland had been established.

  But then July ended in another wet spell. The roof of our wonderful new office leaked spectacularly. Buckets and mops were everywhere. Men with giant sealant guns gradually filled the cracks. Incredibly, August was genuinely good, though the few poor days that occurred tended to coincide with weekends. The month commenced at the Kingcombe Centre in west Do
rset, where Oates's butterfly weekend was running again, after a five-year break. The month then belonged to the Brown Hairstreak. The first was seen at Lydlinch Common, near Sturminster Newton, on August 2nd, in the same Ash tree which the insect had been using in 1997. The Kingcombe group also visited the new Butterfly Conservation reserve at nearby Alners Gorse, where three species of Hairstreak were seen – Brown, Purple and White-letter. Things were looking up. A patch of grassy rubble in Swindon (now the site of a Tesco Express store) even revealed a small colony of Essex Skippers.

  Brown Hairstreaks were emerging well, but on Sunday August 7th, my birthday, butterflying was affected by a tumultuous end to the second Test match, at Edgbaston. Australia began the day needing 107 to win with just two wickets left, and nearly got them. Gloom and despondency descended on all loyal Brits, despite the sunshine – only for England to win by two runs. Millie and I were out Brown Hairstreaking in the Forest of Braydon meadows; or rather one of us was butterflying, whilst listening ardently to the cricket on the radio, the other was reading Chaucer under an oak tree. The diary recalls that A fresh male flew joyously round us in celebration of England's great victory.

  August was devoted to studying Brown Hairstreaks in the Forest of Braydon, whilst listening to England regaining the Ashes. The object was to gain some understanding of the insect's population structure in the district. In other words, discover where they were, when, and in what numbers; where the males were assembling, which Ash trees they were favouring; and above all, try to work out what they were doing, and why. Although I had seen Brown Hairstreak annually since 1969, and had spent countless hours looking either at it or for it at Noar Hill, I scarcely knew it. In Braydon, in 2005, they were found to be occurring in low numbers locally throughout the Blackthorn hedge system, though favouring certain spots, usually the more sheltered pockets. A number of favoured Ash trees were found, most of which are still in use today. But after the males start to die off, usually in late August, the females seem to disperse away from these activity centres, at least in favourable weather, as was the case in September 2005. The last of the year was seen on October 9th, so worn, battered and scale-less that it took me several minutes to identify it.