Mark Colvin

[Matsukaze]

Hi Mark,

Absolutely fascinating.

The Mouse's Pasture was referenced as a Large Blue site in the Reverend F.O. Morris' History of British Butterflies http://archive.org/details/historyofbritish00morr - as Morris gives somewhat different particulars it appears to have been a well-known site at the time (it is an easy name to remember!). I wonder if anything is left of it now, or if any specimens from there survive?

[Mark Colvin]

Hi Matsukaze.

Thanks for the information including the link - much appreciated

Good hunting.

Kind regards. Mark

[Matsukaze]

Just had a quick look at the OS map of the area and one thing stands out. Here in the south-west, the Large Blues always seem to cling to steep south(ish) facing slopes. There is no trace of anything similar at Bromham (on the floodplain of the Ouse), and if I remember rightly the same is true of the other eastern England site, Barnwell Wold. Might the Large Blues have been using a different sort of habitat here?

[Mark Colvin]

Hi Matsukaze.

Thanks for your message.

I've only ever seen arion at Collard Hill, on one occasion several years ago, and have not seen it on the continent nor visited any of the historic localities where it once occurred. Geographically I'd imagine its old haunts to be quite different, at least comparing those that occurred to the east of its range in England to a site such as Collard Hill. This does of course pose the question - if they were living in different isolated environments could these 'races' have been genetically different in any way which may suggest more than one subspecies occurring in the British Isles?

I'm probably wrong but food for thought ...

Kind regards. Mark

[Matsukaze]

Hi Mark,

The best thoughts I can come up with are that M.sabuleti, and therefore the Large Blue, is sensitive to temperature rather than vegetation or landscape, and therefore if temperatures when the ant is active are warmer in Bedfordshire than in Somerset, which wouldn't surprise me, the slopes that are ideal for M.sabuleti will have a shallower gradient (something to do with the angle at which the sun's rays hit the ground, if I remember rightly). I do wonder what the habitat was in the south Midlands, but guess we will never know, unless someone invents a time machine and we can beam Jeremy Thomas back to 1808...

If and when the genetic analysis is done, I would be surprised if the Barnwell Wold Large Blues diverged from the nearest western ones before 1600 - I can imagine enough of north-west Oxfordshire, south Warwickshire and east Northamptonshire being broadly suitable at one point, and these areas were hammered by agricultural improvement before the recording/collecting of butterflies really got going, explaining why we have no records.

The other mystery of the Large Blue's distribution is why there are so few records from the south-east, which is where many of the early entomologists were. M.sabuleti is common on heathland and chalk downland, so why is the butterfly absent? Were such sites too prone to drought? Does it occur in heathy or chalky places on the near continent?

[Mark Colvin]

Hi Matsukaze,

Some interesting thoughts for contemplation ...

I am not aware of any plans for genetic mapping but would certainly be interested to see this done and to know the outcome. There is plenty of usable genetic material in well-curated collections which can provide us with extensive data for investigating the effects of climate change, habitat modification and loss and the resulting distributional changes over time. Although many of the historic specimens housed in museums collections will be unsuitable for molecular research; due to their age, methods of preparation or nature of preservation, there are still many that can provide scientists with valuable data. In more recent years, it has also become possible to extract nucleic acids from dry insects without causing external morphological damage; an important consideration with extremely rare or type specimens.

Certainly with regards to the excellent facilities provided by the Hope Department of Entomology, at Oxford's University Museum of Natural History (OUMNH), specimens are made available to researchers for both traditional (morphological studies, data mining) and molecular research (population genetics, barcoding, molecular systematics), providing their methodologies are scientifically robust.

Watch this space ...

Kindest regards. Mark

Images copyright OUMNH. Photographed by Katherine Child, Hope Department of Entomology.

[David Simcox]

I have thoroughly enjoyed reading some of the recent discussions regarding the historical distribution of the Large blue and of historical specimens.

With regards to the Barnwell Wold sites I had a chat with Jeremy this morning who I knew had discussed them at length with the late Miriam Rothschild. She described them as boulder clays sitting on top of limestone and that she could remember the sites, (not the butterfly), as a child as being completely dominated by huge anthills created by the Yellow Meadow Ant (Lasius flavus). In fact she remembered that it was too dangerous to ride a horse across the fields for fear of them breaking their legs.
Being familiar with similar ‘antscapes’ in other parts of the country, Jeremy and I have carried detailed temperature recording on the undulating topography and heterogeneous aspects of this habitat, we found that they provide the perfect place for Myrmica sabuleti to flourish. Ground temperatures can vary enormously within a few centimetres which is perfect for a thermophilous insect to exploit and it is not surprising that Silver spotted skippers prospered at Barnwell at the same time as Large blues. The Rothschilds were not responsible for introducing Large blues here as the butterfly was present at least 50 years before the family’s interest in natural history began or their association with the sites.

Matsukaze is absolutely correct in his observation that Large blues are sensitive to a temperature niche which must also be occupied by Myrmica sabuleti and at least one of its foodplants, Wild Thyme or Marjoram. Most former English sites were on steep south facing slopes where the ‘angle of incidence’ to the sun raised the soil temperature. Flat sites like Barnwell Wold were warm owing to the micro-topography and shelter provided by anthills but were very vulnerable to the plough. Of course grazing is also vital as short turf leads to warmer soils.
Importantly the phenology of the butterfly, the ant and the foodplant must also be tightly synchronised. This is an area where we have been concentrating some of our more recent research as the de-coupling of the synchronicity, triggered by climate change for instance, would be catastrophic to the butterfly.
In southern Europe the butterfly is seldom found on south facing slopes because it is too hot for the ant.


I think there could be a number of reasons as to why there are so few historic records from Chalk downland, particularly from the south east: Chalk is certainly more drought prone than limestone and we know that drought is bad for the butterfly as it impacts badly on both the foodplant and the ants. Myrmica sabuleti produces bigger nests on thicker soils that are capable of rearing more Large blues – chalk soils tend to be much thinner than limestone. Historically, much chalk downland was sheep grazed throughout the summer and when pushed hard sheep will eat off Thyme flowers together with eggs and caterpillars. Finally, Thyme on chalk tends to flower earlier and may well be beyond the phenology range of the butterfly.

I am not a taxonomist or geneticist, but welcome the time, in the not too distant future, when old specimens can be used to throw light on the genotype as well as the phenotype of this amazing butterfly. We have already done this using fresh material and I can confirm that populations in the UK are already genetically distinct from each other and from their source populations in Sweden - evolution can be very rapid!
Keep up the good work on this excellent site,
David

[Mark Colvin]

Hi David,

Many thanks for taking the time to contribute to this discussion. It's good to get confirmation of the currently known facts from someone who has been so instrumental in the Large Blue reintroduction programme. I am also pleased you have enjoyed reading some of the recent dialogue.

I was particularly interested to note your comment:

I am not a taxonomist or geneticist, but welcome the time, in the not too distant future, when old specimens can be used to throw light on the genotype as well as the phenotype of this amazing butterfly. We have already done this using fresh material and I can confirm that populations in the UK are already genetically distinct from each other and from their source populations in Sweden - evolution can be very rapid!

Rapid indeed ...

With this being the case, I feel it almost inevitable that if old specimens from regional 'forms' are one-day utilised as part of a molecular systematics exercise, they will almost certainly be genetically distinct from each other ...

I also note your comment from 2008

"The separation into subspecies is generally performed by taxonomists who are looking at morphological features on the adult. They tend not to look at the ecological requirements of the species or their behaviour in each developmental stage, for example. Some of the populations we’ve introduced are now 18 generations old. In human terms that would take us back to about 1550. As far as I’m concerned, ecologically, these populations are behaving exactly as the British populations. If you’re going to look at subspecies, there’s a strong argument to say there were 6 regions of Large Blue in this country, and they were each represented by a different subspecies based on the criteria of morphological features".

Keep up the great work.

Thanks again.

Kindest regards. Mark

[Mark Colvin]

Butterfly Conservation, 26 March 2013

2012 was the worst year on record for UK butterflies

We all knew it, but it's now official ...

"Washout 2012 was the worst year for UK butterflies on record with 52 out of the 56 species monitored suffering declines, a scientific study today revealed. Some of our rarest species, such as the fritillaries, bore the brunt of the second wettest year on record and now face the real threat of extinction in some parts of the UK.

Last year’s relentless rain and cold created disastrous conditions for summer species in particular as they struggled to find food, shelter and mating opportunities; butterfly abundance plummeted to a record low as a result and 13 species suffered their worst year on record. The critically endangered High Brown Fritillary fell by 46%, the vulnerable Marsh Fritillary was down 71% and the endangered Heath Fritillary saw its population plummet by 50% in comparison to 2011. Many of our most threatened butterflies were already in a state of long-term decline prior to the 2012 deluge. There are now real fears that these already struggling species could become extinct in some parts of the UK as a result of last year’s wet weather.

Hairstreaks did particularly badly last year - the Black Hairstreak, one of the UK’s rarest species, saw its population fall by 98%. The Green Hairstreak was down 68%, the White-letter Hairstreak fell by 72% and the Brown Hairstreak, slipped by 34%. Many common species also struggled. The Common Blue plummeted by 60%, the Brown Argus collapsed by 73% and the Large Skipper fell by 55%. The widespread ‘Whites’, including Green-veined White, Large White and Small White, saw their populations tumble by more than 50%. The Orange-tip fell by 34%. The alarming slide of garden favourite the Small Tortoiseshell continued, with its population slipping 37% from 2011 figures. Only four species saw their populations increase. The grass-feeding Meadow Brown was up 21% and the Scotch Argus, which thrives in damp conditions, rose by 55%.

Dr Tom Brereton, Head of Monitoring at Butterfly Conservation, said: "2012 was a catastrophic year for almost all of out butterflies, halting progress made through our conservation efforts in recent years. Butterflies have proved before that given favourable conditions and the availability of suitable habitat they can recover, but with numbers in almost three-quarters of UK species at a historically low ebb, any tangible recovery will be more difficult than ever.

Data was gathered by the UK Butterfly Monitoring Scheme (UKBMS) jointly led by Butterfly Conservation and the Centre for Ecology & Hydrology (CEH).

UKBMS has run since 1976 and involves thousands of volunteers collecting data every week throughout the summer from more than 1,000 sites across the UK. CEH butterfly ecologist Dr Marc Botham said: “Despite the horrific weather in 2012 over 1,500 dedicated volunteers still managed to collect data from over a thousand sites across the UK. Their amazing efforts enable us to assess the impacts of wet summers on butterfly diversity.”
The UKBMS is operated by the Centre for Ecology & Hydrology and Butterfly Conservation and funded by a multi-agency consortium including the Countryside Council for Wales, Defra, the Joint Nature Conservation Committee, Forestry Commission, Natural England, the Natural Environment Research Council and Scottish Natural Heritage. The UKBMS is indebted to all volunteers who contribute data to the scheme."

Dr Tom Brereton
Head of Monitoring at Butterfly Conservation



But it’s not too late if we act now …

In Sussex, last ‘summer’ checked the upward population trend for the rare Duke of Burgundy. Nevertheless, our conservation efforts over the previous years means that 2012 will have seen a decrease, not an extinction, of this rare and beautiful butterfly. This tells me that we must highly value and protect what we have. It tells me we must continue to research and keep learning - we may only have 59 native species of butterfly in the UK but there is still much we do not know. We must learn from our successes and we must learn from our mistakes. We must educate and we must conserve. We have no control over the weather but we do over our attitudes and actions – we have the ability to change things.

If you have the time and the ability to get involved with a local conservation project, run by your local branch of Butterfly Conservation, then please consider getting involved. You won’t regret it, and I can guarantee you will get far more out of it than you put in.

We have a responsibility …

[David M]

Couldn't agree more, Mark. Butterflies (and the wider world of nature generally) provide me with so much pleasure that I feel duty bound to help out when I can in order to preserve their environments.

Sadly, despite all the conservation work we can undertake there's nothing we can do about the weather. Several UK species are at the northernmost limits of their ranges, and since I've been a member of this forum (August 2009) we've singularly failed to see even an 'average' summer month. We've had remarkable Septembers, Aprils and Marches but May, June, July and August have recently been setting records for all the wrong reasons.

This has been going on since 2006. When are we (butterfly enthusiasts) going to be ready to challenge the establishment mantra of the last decade or more regarding 'global warming'?

It ain't happening as far as I can see. Even worse, we're experiencing warm spells where they don't belong on an all too frequent basis, leading to heavy population losses when conditions subsequently become abnormally wet and cold. Surely, if this warming phenomenon were genuine, then we'd occasionally be seeing its effects during the period between May and September, but we aren't.

So, the weather here is totally screwed up, but one thing's for sure, it ISN'T getting warmer per se. Perhaps we need to concentrate on sunspot activity as we did in the past or look at previous periods where the weather in summer was abnormally cool for a few years.

Whatever the reason one thing's for sure, our butterflies are suffering at a critical level right now. It's heartbreaking when you're someone who goes out in the field as often as possible and yet at the end of the year you can only claim mere single figures of 'common' species like Small Copper, Dingy Skipper, Common Blue, Wall Brown, Small Pearl Bordered Fritillary, Brown Argus, etc.

[essexbuzzard]

Seconded!
Although we have had isolated weeks-even months on occasion-of good weather,the last sustained spring to autumn of good,sunny weather was ten years ago now-2003!
Surely one good summer every ten years isn't too much to ask?

Global Warming or no,good summers remain such a rarity in GB that people still talk about 1975 and 1976!

This is why we have a mere 59 species. I think our neighbours in France have about 150!

[David M]

This is why we have a mere 59 species. I think our neighbours in France have about 150!

Approx. 220 according to my Llafranchis guide, Buzzard.

[Wurzel]

Would a period of drought be any better? I saw mention on one of the forums that there was some pretty awful weather in the spirng of 1976 so I had a quick google and it turns out that the spring was really cold - in fact there was even snow in the Midlands in June (this is according to an article by Michael "it won't be a hurricane" Fish ) So if a prolonged period of sunny warm weather would benefit the struggling populations lets hope that this is a case of history repeating, though surely a drought would cause different problems?

Have a goodun

Wurzel

ps sorry for the hi-jack Mark

[Mark Colvin]

Thanks for your comments.

What I can report is a beautiful spring day in West Sussex today - albeit a little chilly ...

Heyshott looked wonderful.

Kindest regards. Mark

[Mark Colvin]

Sussex BC Annual Report

Issue 5 (Spring 2013) of the Sussex Butterfly Report, the annual review of the previous year (2012) by Sussex Butterfly Conservation, was published on Thursday. In the next few days, all BC Sussex Branch members should receive their copy of the Report in the post (which also contains the 2013 events listing - an incredible 30 in total). Running to 76 full colour pages, the publication is full of numerous interesting articles and reports on the butterflies and moths of Sussex; including a fascinating article by our very own Vince Massimo entitled, The Forgotten 75% - though you’ll have to buy a copy if you want to know what that’s all about ...

The Report is available to non-members of BC Sussex. We are asking for a minimum donation of £5 per copy, inclusive of postage and packing, with all proceeds going towards the important conservation of butterflies and moths in Sussex; an early purchase is highly recommended. Please email Audrey Kemp at treasurer@sussex-butterflies.org.uk for details.

Please dig deep, it won't be around for long ...

[Susie]

Excellent. It looks fabulous, Mark. I look forward to receiving a copy.

[essexbuzzard]

Me too-this report is outstanding.
Even for non-members,a fiver is a bargain!

[Susie]

It's a beautiful picture on the cover too

[Mark Colvin]

Thanks ...

I appreciate both of your comments. This is of course the result of the hard work of many people …

Mark, you can join our marketing team any day - thanks

Good hunting.

Kind regards. Mark

[Mark Colvin]

Heyshott Escarpment, 27 March 2013

Reflection ...

With our 2012-13 work party season now at an end it is time to reflect, on what has been achieved this past winter, and upon our hopes and expectations for future seasons.

This year we have concentrated much of our clearance efforts on the far eastern sector of the reserve; though others areas have not gone untouched. The clearance of the final few yew trees within the now secure fence boundary, due to their toxicity to livestock, means that mixed rotational grazing (cattle and sheep) of the north-facing scarp can soon commence. This varied grazing, along with selective scrub management, is an essential part of the overall management plan, though must be undertaken sympathetically and with due care and consideration of its effects.

Over-grazing, particularly by sheep, can, and has historically, had a devastating effect on the Duke of Burgundy, as it produces turf which is far too short and which only sustains unsuitable stunted primulas. Our aim at Heyshott, and indeed at other sites where the Duke of Burgundy occurs in Sussex, is the production of a more structurally diverse sward, and eliminating the build up of ‘thatch’ which will ultimately shade out the Duke’s two principal foodplants, Cowslip (Primula veris), and Primrose (Primula vulgaris). Primulas growing within or adjacent to the longer sward are then provided a level of protection and are far less likely to become desiccated during hot, dry summers - it is these large, lush, green-leaved plants that the female Duke of Burgundy will ultimately seek out for egg-laying.

Neil will be leading our 'Dukes at Heyshott Escarpment' open day on Saturday, 18 May 2013.

Details can be found in the latest Sussex Butterfly Report and will appear on the Sussex BC website at http://www.sussex-butterflies.org.uk