Copper Country

In the psyche of nature lovers across Britian, there lie scarcely-imagined, mythic beings. For birders maybe it’s Wood Thrush, Sibe Blue Robin or this weekend’s White – Rumped Swift. These are creatures so rare, so fanciful, that when they flit across our radars and then disappear, it seems impossible to believe they were ever there in the first place. These things lurk in the murk on the edge of our imagination, hardly tangible, and rarely-acknowledged for fear of making them vanish like the puffs of smoke they so often seem to be, and when they appear, do so with such cosmic, earth-shaking clarity that for those lucky enough to meet with them, the image will be burned onto retinas forever.

For people who like butterflies, some might say Camberwell Beauty, or Queen of Spain Fritillary, but perhaps that’s underselling things a bit – beauties, for all their searing power and brawn, occasionally form hopeless territories post hibernation, or loaf around on Buddleias in August (like this one at Pulborough Brooks, which stayed for almost a week in 2006 ) Queens are often eminently well-behaved too (like the ones in Sussex last summer) – stuff of legend though these things undoubtedly are, are they really of the same knee-weakening calibre? To fill this lepidopteran void, there's surely only one candidate - the Large Copper.

Does it cut it? A Camberwell Beauty from Sweden this summer.

There is no doubt that for British butterfly watchers at least, these pass the unattainable test with flying colours, since they’re now a thing of the past as far as we’re concerned, yet that stunning plate in Thomas and Lewington, (illegal!) releases, tales of failed introductions and the possibility of future ones means that they remain ever so slightly tangible for those who dare to dream.

Perhaps more than any other British butterfly past or present, they have become emblematic of something lost, disappearing along with the fenlands they called home. They are creatures of a time when the fens were a largely intact wilderness supporting Cranes and Ospreys, Swallowtails, and a strange proud people, in a swampy vastness stretching from Yorkshire in the North to Cambridgeshire in the South. In other words, there’s something decidedly different, mysterious, and above all wild about the whole thing.

With the exception of some of the northern specialities on their hilly/boggy redoubts, British butterflying sometimes feels quite far removed from this. You spend a lot of your time visiting nice sites with interpretation boards; well-managed, sunlit woodlands, rolling chalk downlands above chocolate box villages, meadows and the like – this is part of what makes it so great, beautiful places on the interface between people and nature, but equally, this is what makes the idea of Large Coppers so thrilling. You can picture them rising in the morning, shaking off a proper fenland fog and then tearing about in a huge, treacherous wilderness that’s remained un-changed for several thousand years, dodging Norfolk Hawkers and picking fights with Swallowtails – it’s a wild and romantic vision when you’re someone that loves butterflies and consequently spends most of their time watching humanity mix a cocktail of abandonment, intensification, heavy pesticide use and increasingly frequent extreme weather events to de-rail these creatures and your happiness.

Lycaena dispar dispar (with thanks to Oxford University Natural History Museum)

Sadly, for the moment at least, a vision is what it remains – for our unique (and bigger and brighter) subspecies, Lycaena dispar dispar quietly disappeared from the fens midway through the 19^th century. This was a mere 102 years after it was first discovered, in 1749, when it was recorded in the minute book of the ‘Spalding Gentleman’s Society’ as the ‘Orange Argus of Elloe’, having been found by the society’s secretary (a Dr John Green) at Dozen’s Bank, in Lincolnshire. Having been ‘discovered’ in this way without much fanfare, the beast then lay dormant and typically wrapped in mystery, presumably only known to a select few or the residents of the fens, and unbelievably,  it was only formally described by Haworth 54 years later in 1803 (probably having heard of it from the brothers William and Fenwick (!) Skrimshire who saw some ‘unusual copper butterflies by the roadside’ near Ely (if Large Coppers and all they evoke was not enough to get the pulse racing, then the thought of an era when there were naturalists with names like Fenwick Skrimshire I hope does).

Typically for such a mythic being, the exact details of the Large Copper’s former occurrence have always been hazy, and even the source of some dispute. This is largely a result of the continued emergence and re-assessment of historical specimens and diaries in old drawers and dusty attics, and their former distribution probably included the Fens and Broads (as far north as the Ouse) and the Somerset levels (on the strength of historical specimens in the Taunton Museum), while some such as Dennis (1977) give credence to records from inaccessible areas in the Wye marshes, ‘not far from Monmouth’.  The key dates are also shrouded in mystery, John Green’s discovery for example, was only realised in 1982, while the date of its extinction tends to be quoted at either 1847 or 1848 (with a series of specimens taken at Holme Fen), 1851 at Bottisham Fen (Cambridgeshire) or 1864 at Woodbastwick in the Broads. Either way, there was little more than a century between the Large Copper’s discovery and its tragic demise.

We’re rather used/de-sensitised to the sad tales of intrepid, under-funded scientists discovering outlandish and wonderful creatures in far-flung parts of the globe, only for an un-helpful oil magnate/plantation owner/natural disaster to make the proverbial coffin and provide the proverbial final nail a heart-beat later, but the rapid extinction of the Large Copper after its description mirrors these daily tragedies that are perhaps often perceived to be the preserve of rapidly-developing countries – the threats that biodiversity faces are old, and sadly nearly always the same it would seem.

Large Blues returned - could Large Coppers?

Webb and Pullin (1997) in their article on the history of the Large Copper in Britain highlight this – the extinction of the Large Copper came at a time when Entomology was exploding in popularity – while a generation of butterfly enthusiasts was learning its trade, leafing through their copies of the Aurelian and dreaming of Large Coppers, so they were fading away, to be lost forever, to take up a special, and painful place in the British butterflying psyche – an extinction symbol of sorts. My generation of naturalists has grown up with hundreds of these, as the roster of the missing and dead following post war agricultural intensification grows. We dream of Corncrakes and Red-Backed Shrikes in every parish, and fantasise about heady days in the Cornish coastal combes in search of the last great English Large Blue colonies, or Chequered Skippers on flowery rides in middle-England Oak woods – tales of these wonders are so widespread in old county avifaunas and collectors’ diaries that they seem almost within reach, despite being doomed to fly on only in day-dreams.

It’s not all bad though, as the Large Blue and Chequered Skipper prove – the former has been successfully restored to our rough limestone grasslands (in the most successful re-introduction of an insect ever), and the latter is hopefully going to go the same way in Rockingham Forest. Could the same be possible for the Large Copper?

At the turn of the 20^th century, most lepidopterists certainly thought so, and gamely went about the task in what has been described by some as the first ever attempt at insect conservation. The first was at the famous former stronghold, of Woodwalton Fen, and wasn’t much of a hit thanks to a lack of foodplant. Further attempts followed in 1913 (bizarrely, in Ireland, where Large Coppers have never been recorded), 1926 (at Woodbastwick Marshes in the broads), 1930 (Wicken Fen, lasting until 1942 when part of the fen was re-claimed) and 1949 (near Surlingham in the Yare Valley) which were all ultimately unsuccessful.

Lycaena dispar rutilus from the introduction to Greenfields, Tipperary, Ireland (with thanks to Oxford University Natural History Museum).

Given the sad non-existence of Lycaena dispar dispar, the introductions had to look to other sub-species for their stock. There are two of these in Europe, of which the most widespread is rutilus, thinly scattered and in retreat across central and eastern Europe (but making some gains in the North). This sub-species is slightly smaller and duller than the mighty dispar, and also tends to be a bit more flexible, typically having two broods (with some suggestion of 3 in eastern Europe) and feeding on a larger variety of dock species (rather than just the Great Water Dock, Rumex hydrolapathum). In 1915 however this became surplus to our proto-conservationists’ requirements, when  Lycaena dispar batavus  was unearthed in the fens of Friesland, Holland (before reading any further, check out this truly superb photo of a female by Mark Hulme, brother of the mighty Neil). Remarkably, this happened on maybe the most gripping school trip ever,  discovered by a party of children out on a nature ramble (once, I was proud of my 2 Dotterels on a school trip to the Brecon Beacons, now, less so).

Specimens of Lycaena dispar batavus from the Woodwalton re-introduction (with thanks to Oxford University Natural History Museum)

Batavus is rather more similar than rutilus to our native dispar, being big and bright, feeding only on Great Water Dock, and being more or less restricted to damp fenlands (it’s also always been said to have 1 brood, like dispar, but with nature’s typical disregard for textbooks, it’s had quite a good second one this year). This made it the favoured stock for later introductions - to Wicken Fen and Surlingham, and most famously to Woodwalton Fen again in 1927. This latter re-introduction is the best-known one as it survived (with a great deal of artificial assistance) until 1969, with several further introductions until the programme was suspended in the 1990s, and is thus perhaps the main reason for why Large Coppers still seem vaguely tangible so-long after their original extinction.

I’ve always struggled to work out what the exact reason for the failure of the (well-studied) Woodwalton re-introduction was, the larvae seem to have suffered much higher over-wintering mortality than their Dutch counterparts in the Weeribben (though it’s not clear why), and they also suffered with the cosmopolitan tachinid parasite Phryxe vulgaris.

The Tachinid parasite Phryxe vulgaris - the scourge of early re-introductions at Woodwalton Fen

The big driver behind the failure of this re-introduction seems to have been high over-wintering mortality, but the causes of this aren’t entirely clear. A comparison by Webb and Pullin (1997) of patterns of winter mortality in larvae at Woodwalton and in the Weeribben  suggested the causes were broadly similar, but mortality significantly higher at Woodwalton. Webb and Pullin suggested genetic problems resulting from inbreeding as the likely cause. This makes sense, the stock of batavus used in the re-introduction (and subsequent top ups) was maintained in captivity for a long time, and the ‘wild’ colony shrunk to just a handful of individuals on several occasions. With such repeated bottlenecks, genetic deterioration seems inevitable.

This situation is not unique to the Large Copper at Woodwalton, and genetic deterioration resulting from small populations has been shown in a number of the more endangered British butterflies (like Adonis Blues and High Brown Fritillaries). This highlights an important point about re-introductions and conservation generally – you need to go big to ensure large, well-connected populations, to work on whole landscapes to get long term success. The drainage of the fens involved habitat destruction on a truly epic scale (over 99% was lost) and was all but complete with the draining of Whittlesea Mere (the Large Copper’s former heartland) in the 1850s, meaning that Woodwalton Fen was just a blemish on a giant carrot field by the time the cavalry (complete with batavus) turned up. As such, the Large Copper re-introduction was maybe always doomed to fail. Duffey (1968) who did much of the early pioneering work on batavus at Woodwalton sadly concluded that it was ‘unlikely that a viable population could be permanently maintained under natural conditions because the habitat is too restricted and the population will probably never be large enough to withstand fluctuations’.

The Large Copper project (as it was) was dis-continued in the 1990s, about the time that I popped out into the world, destined to be a lucky recipient of the European Butterflies Group grant to go to Hungary in summer 2017. My main purpose there was to help with mark-release-recapture work of Large Blues in the Fertő-Hanság National Park, but the trip was rife with ulterior motives from the start. While Large Coppers continue to decline in western Europe as their wetland habitat gets fragmented, in some eastern European countries (like Hungary), they remain fairly widespread, though never common. Here, subspecies rutilus is the order of the day, with a slightly wider range of dock foodplants than batavus and dispar, it manages to be a bit more adaptable and widespread. Interestingly, it’s been found to be positively associated with human habitation in Estonia, thanks to its use of dyke side docks for egg-laying – ironically adapting to the drainage mechanisms that were the architect of its destruction in the UK.

In the Fertő-Hanság, Large Coppers are in fact in rude health, so much so that when I asked (within my first half hour of getting off the plane) whether I was likely to see Large Coppers, my boss (Andras Ambrus) openly scoffed at my naiveté. I’ve never been so delighted at someone laughing in my face.

Nagy tuzlepke - the Fire Butterfly - my first ever Large Copper

He proved of course, to be quite right in doing so, with my first coming on the 24^th of July, a couple of weeks after I arrived. Inevitably it is the most memorable, it’s also the only one I’ve got any real notes on, as I lost my second diary from Hungary, started shortly after. It was a male at my favourite of the Large Blue sites, a scrubby, flowery marsh on the edge of a small village, ringed by poplar plantations beloved of Golden Orioles. I flushed it out of the grass as I crashed through some sallow scrub for the nth time that morning, and it helpfully landed a couple of yards away. It took a moment for the full brilliance of the thing to dawn on me, as in flight the orange upperside and silver-blue underside combined to give a rather purply impression (a bit like a Purple – Edged Copper), but once it landed, wings spread, dawn it most definitely did. As you do in these moments, I stood in rapt silence feeling like the air had been knocked out of me, before mustering the courage to kneel and display the proper levels of deference/take photos.

Large Copper - Male

After my first audience, I had to wait another week (guarding my memory card in the interval with new levels of paranoia, determined to have proof that it wasn’t all a waking dream brought on by 8 years of fantasising), but then the floodgates opened, and while they didn’t release a surging mass of winged fire on the land, I saw Large Coppers fairly regularly after that.

Large Copper - male in the evening.

Generally, this was in ones or twos, rather like Small Coppers (third broods aside), they seem to be low density butterflies, fanning out far across the landscape in small numbers, often turning up far from ‘typical’ habitat. This is a butterfly of big country, and it’s easy enough to see why it could never thrive in the postage stamps of fenland we’ve thoughtlessly left for it back home.

In my imagination, feeding off the stories of huge swampy wildernesses where our dispar was found, I’d thought I’d be seeing Large Coppers in pristine marshlands, perhaps skimming distantly and frustratingly over vast reedbeds or rush-meadows. The reality of their fairly wide distribution in the Fertő-Hanság was far more prosaic (and heartening). In fact, the best site I saw for them, where I managed a monumental (by Large Copper standards) 15 individuals, was the canal pictured here – choked with the invasive goldenrod, with trains thundering over the bridge (where the picture was taken), and questionable graffiti on the underpass below – hardly a pristine wilderness, but all the better for it.

Hardly wilderness, but all the better for it - the best site I saw for Large Coppers in the Ferto-Hansag

This is one of the surprising features of Large Coppers in Eastern Europe (at least from a British point of view), where it’s bivoltine (which rutilus is almost all through its range, sometimes even with a sneaky third brood) the second brood seems to be far less constrained than the first, using a greater variety of foodplants, often in very dry situations (like urban waste ground), with the females dispersing far and wide in search of them, while males set up territories in flowery meadows (presumably why there were so many by the canal). I’ve not found a good reason for this (if anyone knows a paper on it I’d be really interested), but it has striking parallels with other specialists – Adonis Blues for example, are less fussy about where they lay their eggs in spring than in autumn, since warm summer temperatures mean their larvae can survive in taller, cooler swards.

Large Copper - Male

I resolved to see as much as possible of the Large Coppers during my 6 week stay, and apart from a frustrating (but memorable) Saturday trying to bait Lesser Purple Emperors out of poplar plantations (tasteful variety of Hungarian pates all refused), I spent all my days off trying to get to know the vanished deity that had dominated my day dreams since for the last 8 years.  Where they occurred, males were reasonably easy to locate, although they spent long periods stationary when holding territories, they tended to do so around prominent patches of flowers (like Purple Loosestrife and the dreaded Canadian Goldenrod), and give the game away with the occasional patrol flight. ‘Patrol flight’ makes it sound systematic and focussed, like they slowly search every nook and cranny of their tiny marshy kingdoms, but the reality was more fighter jet than infantry patrol, the butterflies tearing up and down at breakneck speed, often covering quite large distances, before returning to the same patch of flowers once more.

What male Large Coppers live for - the chance to court a female. This one wasn't interested though.

Large Copper - Male

I didn’t see many females, maybe 5 or 6, probably because their behaviour was much more furtive (tending to spend a lot of time sat low in the grass), and they weren’t tied to nectar-rich territories where I searched for males. I did see one egg-laying towards the end of the trip, on a small dock re-growing in a cut meadow, zipping over the grass before turning on her heel and dropping into the vegetation to deposit her flattened white cargo on a dock I’d totally failed to notice in all my sessions marking on the site. It’s one of the best demonstrations of the extraordinary sensory abilities of butterflies that I’ve seen, and she evidently wasn’t the only perceptive female about, since a quick check of the underside of the leaves revealed a first instar larva and several more eggs.

Large Copper - female warming up early in the morning.

Large Copper ova - on a small re-generating Dock in a cut meadow

Large Copper ova - these were 3 of 11 on a tiny little dock on dry, urban waste ground.

I found eggs at several sites during my stay, on a variety of dock species - huge dyke-side Great Water Docks and tiny, re-generating docks in cut meadows, and even on dry waste-ground. The plant pictured below had 11 eggs on it, growing in the dry, rocky grassland by an old gravel pit. Nearby plants on the damp margins of an old pool (surprisingly) had none on them. These contrasting egg-laying sites meant that the few eggs that I found didn’t really give me much of an insight into what it was that constrains Large Coppers, which makes sense given that this was the all-singing all-dancing, un-constrained second brood.

First Instar Large Copper larva - on a regenerating Dock in a cut meadow

Large Copper larva

While Large Coppers seem (for now at least) to be doing fine in the Fertő-Hanság national park, and even expanding in parts of northern Europe, the picture in north west Europe is nowhere near so rosy, after their loss from the UK, Large Coppers have declined in the Netherlands and France, Northern Germany and parts of Italy, meriting their inclusion in the both Annexes of the EU Habitats Directives as a species deserving protection in its own right, and its designation as a Natura 2000 species more recently. Despite this rather bleak outlook though, some British lepidopterists keep a faint spark of hope alive in the form of a pioneering project in the Large Copper’s former heartland.

Large Coppers rarely vary from the type, but I was lucky enough to find this ab. radiata, the last Large Copper of my trip, on my final day of marking.

This spark is the Great Fen project, a landscape restoration project from before we had re-wilding (and it became cool), which aims to reconnect Holme and Woodwalton Fens with 37000 ha of restored fenland. These two National Nature Reserves are of course two of the Large Copper’s former strongholds (with the release at Woodwalton and those late specimens at Holme in 1846/7) and while the project doesn’t explicitly mention Large Coppers in its aims (instead focusing on species like Bitterns, which fortunately aren’t extinct in the UK), it’s hard not to feel a faint flash of optimism.

Perhaps with this new habitat, and climate warming leading to a newly bivoltine and un-constrained batavus, we could once again see Large Coppers thriving in East Anglia. It’s a compelling vision, a landscape restored and the return of its most iconic native, and with the success of the Large Blue (and the on-going Chequered Skipper re-introduction), it’s clear many organisations have the will to take on these ambitious projects. Perhaps, armed with the right knowledge and a central philosophy of landscape-scale conservation, connecting up sites and people with these fantastic creatures once more could be possible.

Large Copper - male at roost

Large Copper male - at roost early in the morning. This was at the canal site, where loose 'communal' roosts formed in the evenings (with a couple of individuals sharing the same patch of vegetation). Roosting was nearly always just below the top of the vegetation (about two thirds of the way up), always in sedges. 

References

I’ve been interested in Large Coppers for a little while and read some stuff while writing this blog, though haven’t really referenced properly. Here’s a list of the stuff I read, and some useful sources of information should you too feel the spark…

Salmon M.A. and Edwards, P.J. (2005) The Aurelian's Fireside Companion: An Entomological Anthology. Paphia Publishing Ltd, Lymington. – Compiles lots of diaries of old collectors, with some nice tales of days in pursuit of dispar dispar.

Salmon M.A. (2000) The Aurelian Legacy - a History of British Butterflies and their Collectors: With contributions by Peter Marren and Basil Harley. Harley Books. – Similar (excellent) stuff.

Lindman, L., Remm, J., Saksing, K., Sõber, V., Õunap, E., Tammaru, T. (2015). Lycaena dispar on its northern distribution limit: an expansive generalist. Insect Conservation and Diversity. 8 (1), pp.3-16. Interesting paper about the spread of Large Coppers in Estonia, here it has managed to be a real generalist and is positively associated with human habitation (remarkably).

Dennis, R. (1977) The British Butterflies: Their origin and establishment. Faringdon, Oxfordshire. Lots of interesting ideas about how the British butterflies established after glaciation – very dense though!

Pullin, A. (1997). Habitat requirements of Lycaena dispar batavus and implications for re-establishment in England. Journal of Insect Conservation. 1(3), pp.177-185.

Pullin did a lot of work on Large Coppers for Woodwalton in the 1990s, all of which makes for interesting reading. This has a comparison of survival at Woodwalton and in the Weeriben, and considers a re-introduction in the Broads.

Duffey, E. (1968). Ecological Studies on the Large Copper Butterfly Lycaena dispar Haw. Batavus Obth. at Woodwalton Fen National Nature Reserve, Huntingdonshire. Journal of Applied Ecology. 5(1), pp.69-96. The big early work on Large Coppers, very long, but worth reading to get a feel for how the re-introduction worked.

Webb, M. and Pullin, A. (1997) – The Orange Argus -  A history of the Large copper butterfly in Britain. British Wildlife. 9 (1). Nice, short summary of Large Coppers in the UK.

UK Butterflies on Large Coppers – always a great summary, with brilliant photos.

Thomas. J. and Lewington, R. (2014). The Butterflies of Britain and Ireland. Bloomsbury, London. – The new, revised edition of the ultimate classic, mouth-watering plate and another great summary.

Andrews, P. (2015). A History of the British Large Copper Lycaena dispar dispar and the Scarce Copper Lycaena virgaureae in Somerset [Online]. Available from http://www.dispar.org/reference.php?id=102 [Accessed October 16, 2018]. – The latest word on Large Coppers in the south west (following Sutton, 1993), makes exciting reading for fellow Wurzels.

There's lots of other stuff out there, with plenty of random articles on old specimens and diaries, and published work by Pullin and Dutch Researchers which I sadly didn’t have time to read while writing this, all of it no doubt fascinating stuff that will only add to the mystery and allure of Large Coppers!