Dukes On The Wane

Sadly, the Duke of Burgundy season is now on the wane and my 2013 survey of all Sussex sites will probably be complete by the end of next week. However, there are still some highlights to be enjoyed, such as the count of 9 males at Harting Down this morning (31st May); none were seen here last year. This site is mountain goat territory, and very seldom visited by anyone else, so it's a great place to escape from the crowds and just melt into the landscape. The views across the West Sussex/Hampshire border are spectacular; this morning they were enjoyed to the soundtrack of skylarks and a distant cuckoo.

After a disappointing count (2) at a private site, I headed to Heyshott Escarpment, where once again I was alone with the Dukes. Although I managed a healthy count of 18, including the beautiful female pictured, the numbers are now dropping off. The Duke is no longer the most common species on the slopes, overhauled by both Dingy Skipper (37) and Small Heath (46). The latter seems set for a good season. Other species included Pearl-bordered Fritillary (1), Green Hairstreak (3) and Grizzled Skipper (3). If you haven't had your fill of Dukes yet, get out there this weekend.

Duke of Burgundy Reintroduced to Bradenham Valley

In the spring of 2011 the NT, in liaison with Butterfly Conservation and Natural England, carried out an officially-approved reintroduction of His Grace the Duke of Burgundy to two small and almost-adjacent chalk grassland sites in the Bradenham Valley, west of High Wycombe in the Chilterns.  The butterfly had died out there circa 2000.  Fortunately, the reasons behind the extinction have been identified and addressed, and habitat conditions have improved greatly.  The two sites support other invertebrates with similar requirements to His Grace, notably Small Blue and Dark-green Fritillary butterflies and the rare bee-mimic hoverfly Microdon devius.

The chances of natural recolonisation were deemed extremely slim, though there is a small colony, the last in the south Chilterns, along a railway line over 2km away.  This is isolated from a developing matrix of chalk grassland habitat patches in the Bradenham valley by intensive agriculture.  The butterfly has declined drastically in the Chilterns during the last 20 years.

In late May 2010 91 eggs were harvested from the Ivinghoe Hills (NT) further north in the Chilterns.  These were bred through in captivity by Ched George of BC Upper Thames Branch.  From these, 29 adults were released at Small Dean Bank and 25 at Park Wood in the spring of 2011.

Close monitoring, mainly by Ched, revealed a reasonable colony at Small Dean Bank in 2012.  The peak count there was 14 (3 females, 11 males) but only a maximum of 2 was recorded at Park Wood. 

On Mon May 27th this year, in windy weather which hinders this butterfly considerably, 3 males and 1 egg-laying female were counted at Small Dean and a max of 4 males and 1 female at Park Wood.  We undoubtedly under-recorded due to the windy conditions, and would probably have seen twice as many had we visited in calm sunny weather.  At least three of the adults seen were freshly emerged, and it is likely that a few more adults are due to emerge.  Habitat conditions have improved further.  Hopefully enough eggs will be laid during this poor spring to see the butterfly through into next year. 

Gaining official approval necessitated 4500 words of reports and letters, plus some emails and phone calls.  Both donor and receptor sites are SSSIs, so double approval had to be obtained from Natural England.  Internally, all wildlife releases and extirpations have to be approved by the NT's Natural Environment Panel.  This required me to write a 1500 word report and attend a Panel meeting.  The Panel approved the release but expressed some concern as to the long term future of the butterfly in the Chilterns under a climate change scenario - the Chilterns may become too drought-prone for a butterfly whose larvae depend on Primula leaves that remain green well into the summer.  The Panel was, though, impressed by the Trust's vision for recreating chalk grassland in the Bradenham Valley (where several areas are being restored to downland from agriculture or forestry).  Hopefully the butterfly will 'take' properly at Small Dean and Park Wood, and then spread to other places within the Bradenham Valley.  The butterfly needs some decent weather though, and cannot have laid many eggs yet this season....

Small Dean Bank

His Grace, at Park Wood

Hampshire Dukes

Got out really early today and didn't get home  until 7pm! Made the most of the weather.... First call was magdalen hill down and it was pretty quiet as I was early but saw good numbers of green hairstreaks  including six doing battle when two holly blues joined in - mayhem. Then went over to St Catherine's hill and was a bit disappointed  - no downland species at all but good counts of peacock brimstone and orange tip.
I then visited an adjacent site I had been told about to check it  for dukes. At first it did not  seem very appealing with waste height nettles which caused some grief but I persevered and eventually found good numbers including a mating pair - this was a new site for me so very pleasing.
This site is 'open access land' and there seems to be some scrub clearance but little grazing. The Dukes were spread along several hundred meters of the lower part of the hill so potentially great site with some careful management but I dont know who is responsible fir managing it?
I then ventured to Beacon hill in th Meon Valley again to search for Dukes but with only one tentative siting it was a bit disappointing but again very good numbers of GH.
Then across the valley to Old Winchester Hill very few butterflies around but managed to locate the small colony of Dukes spotting five in total including two females.
There was just time to finish in my favourite spot in Rake Bottom where again saw a few Dukes settling in for the evening - fantastic day seeing Dukes at three different sites  Mark

Counting Dukes

The last two days (25th & 26th May) have been pretty typical for me at this time of the year, involving a mad dash to try and survey all of the Sussex Duke of Burgundy sites as thoroughly as possible. Although numbers will take another season to recover, there does at least seem to be a viable population remaining in the areas I've visited so far; sometimes only just. That's quite a relief after last year's weather, but I do have doubts that the national tally will remain unaffected by the 2012 washout. I recorded 55 Dukes over 6 different sites and on some of these the butterfly is still emerging. Along the way I'm seeing reasonable numbers of Dingy Skipper and Green Hairstreak, although the Grizzled Skipper isn't faring quite so well. While searching an area of Rewell Wood today I saw 7 or 8 Drab Looper moths, so they seem to have weathered the storm quite well. These frail looking insects are a lot tougher than we give them credit for.

Dukes Launch 'Save Our Butterflies Week' In Sussex

I'm pleased to say we were blessed with decent weather and a good turn-out of both people and butterflies for the BC 'Save Our Butterflies Week' launch event in Sussex, held at Heyshott Escarpment on Saturday 18th May.

On the walk itself we saw 20 - 30 Duke of Burgundy without straying from the footpaths. I later returned to scour the site and counted 42, including 3 females. I estimate they are still a week to ten days from peak here.

Perhaps the biggest surprise was the discovery that Pearl-bordered Fritillary has moved onto the site. I was gobsmacked to see a male during the walk, and even more surprised to later watch a female PBF make her first, unsteady flight. They used to occur along the Downs here in the C21st, so this might signal a welcome return. It's 11.5 Km to Rewell Wood, where the species thrives, so I suspect they've been hiding out in Charlton Forest, just over the ridge from Heyshott.

45 Years On, and counting...

In 1968, when the world was young and heady, the 19th of May fell on a Sunday, as has been the case this year.  Spring that year was slow, but sure, and gave the impression that sooner or later something mighty was going to erupt within the world of Nature.  It did, on May 19th. 

But May 19th 1968 began with school chapel, which dragged on till 10am.  It was, of course, compulsory at boarding schools in that era – on pain of severe pain.   Between chapel, and the equally compulsory but utterly inedible Sunday lunch, was an opportunity of less than three hours to go butterflying.  Consequently, I ran, in heavy school shoes, dressed as a penguin in full school uniform, the two and a half miles to Marlpost Wood.  I entered the wood at the zenith of spring, with the heady scent of bluebells in the air, stuffed my school coat under a bush – and crossed rapturously into a new dimension, the real world.

There, to an eternal delight that must now be shared, I saw my first Pearl-bordered Fritillaries and what was then known as the Duke of Burgundy Fritillary.  It must be confessed that I still refer to the latter as the Duke of Burgundy Fritillary at every opportunity, for butterfly enthusiasts fall for the names they first learnt – and, as Aslan himself put it: ‘Once a king and queen in Narnia, always a king and queen in Narnia’.  The Pearl-bordered was undoubtedly the most beautiful thing I had seen in fourteen years of life, on account not merely of the juxtaposition of colours, but of the grace with which it flies.  The magic is compounded by its affinity with the exquisite blue of its beloved bugle flowers.  The Burgundy was evidently a living jewel, and a butterfly of strong character. 

Both butterflies occurred around a few acres of young plantation, where rows of oaks had been inter-planted with lines of Norway spruce, as a nurse crop, next to a broad sunny ride bedecked with clumps of bugle and stitchwort.  Speckled yellow moths were hatching, and flopping around amongst bracken fronds old and new, fair weather cumulous clouds were drifting lazily above, for atmospheric pressure was rising, and a distant nightingale sang snatches of some Elysian song.  Will people who do not believe that Paradise exists upon this earth kindly revise their views: it does, only it tends to be transitory and intensely episodic, and you have to be in the right place at the right time.  Moreover, human nonsense, such as compulsory chapel, is forever getting in the way of it. 

A horribly soppy and na├»ve song by a group called The Honeybus, who mercifully had only the one hit, was riding high in the charts in May 1968, and was in my mind throughout and beyond that visit.  Years later I rewrote I Can't Let Maggie Go, slowed it down and removed the annoying falsetto parts, and attempted to give it some decent lyrics.  This heavily revised, near-paganised and unrecognisable version is my song of the Pearl-bordered Fritillary, but like so much of what one holds dearest is inappropriate for open communication.  We dare not come out at that level, I know not why. 

After an hour and a half in Paradise I ran back to school, in time for the compulsory lunch.  But I had left something behind in the woods, part of me.  Instead, I had taken something with me, not merely a couple of specimens of each species, which I set that afternoon, for people collect memories and forge relationships with places.  Marlpost Wood has changed unrecognisably since that day (most of it blew down in the Great Storm of October 1986), and so have I.  But we remain intertwined, and her Duke of Burgundy and Pearl-bordered fritillaries dwell still within me, not merely within my mind, or my imagination, but within my soul.

Suffice it that 45 years on, to the very hour, I rekindled first my relationship with His Grace the Duke of Burgundy Fritillary and then with the Pearl-bordered Fritillary.  The only significant difference was that Sunday May 19th 2013 was Pentecost Sunday (when the churches celebrate the coming of the Holy Spirit to the Disciples).  

I spent a pleasant afternoon in welcome sunshine walking across  the ' north face' of Butser Hill in Hampshire. From little Butser I could see Neil's domain in Sussex.  Despite there being some good habitat on Little Butser  and on Ramsdean down I did not locate any dukes but I will be back to check again.
However the story was different at Rake Bottom where I came across at least sixteen individuals with at least a couple of females. This is much more like the numbers I would expect to see in early may - hopefully they have caught up.
There seems to be two colonies here the largest in pristine habitat and the other smaller one in an area heavily grazed by rabbits,  having seen some of the areas available at Ramsdean it is a bit perplexing why they haven't been occupied yet.

His Grace Takes to the Air

The BBC Natural History Unit will be filming His Grace the Duke of Burgundy at Rodborough Common, Stroud, this Friday, May 17th, for a forthcoming Springwatch Special on British butterflies and moths.  We hope to be filming at Manor Combe and on Swellshill Bank.  Apologies in advance if we hog the place... .  Strangely, it looks as though this butterfly hasn't appeared on mainstream TV before.

I particularly want the piece to cover the love life of this little butterfly (he doesn't even ask her name, let alone speak to her father, propose on bended knee and get the banns read out in church.  In fact, no one would want their daughter to associate with a bloke with the morals of a male Duke of Burgundy).

Hampshire doings

I paid a visit to several areas around Butser Hill near Petersfield today and butterflies were very few and far between. Having explored some new areas that look very promising and found no dukes, it was very windy, I walked over the hill  to rake bottom where I had bumped into Matthew last week. The weather was deteriorating but I manged to track down just one male in a shetered hollow. Taking the opportunity to sit and watch with my binoculars for the next two hours i picked up some details of behaviour. No other males passed during this time although he did see off an Orange Tip that dared to venture too close - I would definitely feel that only a small proportion have emerged to date. The butterfly was seen nectaring on several flowers of Lesser Celandine and The photo shows a small fly of unknown species that was in attendance for about half an hour. It would perch at various locations, within about a centimetre, always facing the butterfly. Mark.

There is always hope...

Delighted to read that the slightly crippled male first noted in the main territory on Rodborough Common on Sat May 4th managed to find a mate and thoroughly express himself as a male Burgundy (see Simon Primrose's post of May 6th).  When he first appeared on Sat 4th he could hardly fly, his wings were too soft.  He had probably been unable to expand his wings properly as he emerged on a windy day and probably got buffeted whilst drying his wings, having crawled out from amongst a matted grass tussock, plus or minus moss.  Weak individuals are easy prey for the hunting spider Pisuara mirabilis, which is numerous amongst grass litter in Burgundy country and regularly takes mating pairs (favouring the female).  But his wings then set hard, enabling him to rampantly fulful himself.  Gentlemen, he is an example to us all... .  Here he is -

Unfortunately the jet stream has jumped south, ushering in foul and abusive weather.  My guess is that about a quarter, or at most a third, of the 2013 adult emergence has come out so far, but the worry is that the remainder, the bulk, may not be able to hold back from emerging indefinitely: they will quickly perish if they fail to hold back and are forced emerge during a sunny hour in a wet week. 

Very worrying, and not simply because I'm supposed to be helping BBC NHU to film His Grace as part of a Springwatch special on British butterflies & moths...  

First Sussex Duchess

Yesterday (11th May) I met up with Charlie Elder, author of 'While Flocks Last' (2009), an account of his quest to see all of Britain's endangered (Red List) birds. Charlie had travelled up from Devon, specifically to see the Duke of Burgundy, despite a highly dodgy weather forecast. When I set off from Worthing it was still raining, but by the time I approached Heyshott Escarpment via the familiar country lanes, the sun had appeared and it seemed a little less windy than of late. We spend a very enjoyable few hours on the slopes chatting about butterflies, and specifically the problems facing the Duke. It will come as no surprise to learn that this species will make an appearance in Charlie's next book. It sounds like a very interesting project, but I shall say no more than that. His first effort got excellent reviews.

We had only seen an Orange Tip and Green-veined White on the way up to the reserve, but soon after 11.30 am the first Duke appeared. Closer examination showed this to be my first Duchess of the year, with a fat abdomen bulging with as-yet-unfertilised eggs. We soon started to find more, including a second female. One pair of males provided my first clash of the season, but they didn't ascend to any great height given the gusty conditions. It was over all too quickly as the clouds rolled in, but I think Charlie returned to Devon with a smile on his face.

Duking In A Gale

Today (9th May) I started off at Rewell Wood, where I hoped to confirm that the Pearl-bordered Fritillary has finally started to emerge, particularly as I'm running a guided walk here this coming Sunday (12th May). I was mightily relieved to spot a freshly emerged male quite quickly. I then received a phone call from Mark Colvin, who had found a male Duke of Burgundy in a nearby woodland on the Norfolk Estate. It wasn't keen on flying in the strong, cool breeze, so it kindly waited for 30 minutes while I drove there. In fact it was so docile that I picked it up for a good close look at my equal favourite butterfly (image by MC).

I then headed off to Heyshott Escarpment where the emergence is well underway. The wind was now very strong and increasing, conditions which the Duke of Burgundy hates. Despite this I managed to locate 4 very fresh males, all showing that lovely blue lustre which typifies a newly minted Duke. These were the only butterflies brave enough to be out on the slopes. Sadly we are due for more of the same weather over the next few days, and that's likely to keep their heads down.

Mating Pair at Rodborough - Mon 6th May

Just a very quick note to say that I saw a mating pair of Dukes at the main colony site on Rodborough Common yesterday. The male had slightly deformed hind wings, that hadn't developed properly, and had apparently been first seen there 3 or 4 days previously. No other Duke sightings, just those two.

Masses of other butterfly activity though, but mainly restricted to this same small, sheltered, area in which the Duke colony is centred. As well as the usual common spring species I saw a Speckled Wood, about 8 or 9 Dingy Skippers and, if I said I had 40 sightings of Green Hairstreaks, I think that would be a gross UNDER-estimate!! Looks like they're going to have a great season!

Mon May 6th

Here's my diary entry for today.  Please note than on this day in 1990 I counted 96 Duke of Burgundies along the Noar Hill transect route (1 hr 15 mins), and only failed to get the century up because a butterfly photographer had displaced most of them from the best area (23 years on, and I'm still cross)...  The pit names will mean nothing to you - suffice it that they all have names, some of them two or three.

Mon May 6th              May Bank Holiday
Perfect!  Cloudless till some haze development late on.  Calm.  22C. 
Noar Hill, Selborne.  9.05-11.40.
I arrived to sound of the lark ascending, then left to the screaming of jays.  The first Duke of Burgundy Fritillary of the year was seen here by Tony James last Wed, the 1st.  This was also the first seen nationally.  I was surprised it began so early in this late spring (in the late spring of 1986 it didn’t start before May 16th, though the start of the month was poor).  Today, although I arrived a little early in the morning, it was apparent that the butterfly hasn’t got going here at all properly yet.  I struggled to see 10 males in a good search of the pits, all bar three of which had been out a day or more.  Tony began the transect at 11.30 and totalled only 6, though he reckoned he under-recorded due to disturbance by photographers.  Nights have probably been too cool for any significant emergence.
I saw my first at 9.25, in the Gooseberry Pit.  Then no more until one at the entrance to the Bromus Pit.  Then, remarkably, none in two visits to S10 / the Woodspurge Bank (and Tony recorded none there too), but I saw another male at the end of S12.  Also singletons in the Rubi Pit (todays), Willow Warbler Pit, Yellowhammer Pit, then 3 in KVP (S3) and one in the entrance Quarry Pit. 
The good news is that habitat conditions are great for this butterfly.  No rabbits and there’s just been some light winter sheep grazing in the Middle Pits.  It looks like a good cowslip year generally, certainly so here, with frequent flower heads over the whole reserve.  The turf height is currently perfect for Duke of Burgundy, 12-20cm on average, with plenty of moss and matted F. rubra tussocks etc.  That’s the good news. 
Butterflies were scarce generally, though I started a little too early.  Good to see a Holly Blue around one of the Rubi Pit hollies and glimpse a Dingy Skipper (Noar Hill’s first of the year) in the Bee Orchid Pit. 
I managed 5 Orange Tip males, including three together in the Quarry Pit, fighting.  Only 2 Green-veined White.  1 Small White in S12 and a lone Brimstone male in the Quarry Pit (Tony reckons all the buckthorn bushes have been cut down…).  Also 4 Peacock. 
Good to see Osmia bicolor in S10 and 2 Bombylius discolor.  Neither species occurred here in my era. 
Very much silent spring here, with not a single willow warbler.  The saving grace was common whitethroat – I heard 8, which isn’t bad.  Strangely, a trio of tree pipit – 1 in S8 and a pair above S12.  But whitethroats apart the place was rather silent…
Tony’s transect figures: 6 Duke of Burgundy, 4 Orange Tip, 3 Brimstone, 2 Comma (in S1, only I didn’t see them), 1 Peacock, 1 Green Hairstreak and 1 Small White. 

Rake Bottom, Butser Hill.  Hants.  12.15-1.15.
My first visit here for some time.  The northern end of the combe, where the slope is west-facing, has developed a sizeable Duke of Burgundy Fritillary population.  Dan Hoare counted 40 in this area on 24/5/2010.  There are several acres of steep slope here with frequent cowslips amongst 10-15cm matted F. rubra turf with frequent clumps of B. sylvaticum here, with patches of hawthorn scrub.  Hairy Violets are also pretty good, so Dark-green Fritillary may be quite reasonable here too.  Round the corner, after the combe twists, the southern half of the slope is as it was – very short turf with open air rabbit burrows and areas of bare chalk.  HCC has recently cleared areas of moderate to dense hawthorn-dominated scrub in the northern half, which should benefit Duke of Burgundy. 
I saw only 4 Duke of Burgundy here, all in the main area, 3 fresh males and a fresh female.  All had emerged today probably.  Looks like the season is even less advanced here than at Noar Hill. 
Also, great to see 8 Grizzled Skipper.  7 territorial males, one tussling with a Duke, and a fresh female – who blundered into a male territory and was instantly courted (I lost them).  Obviously, quite a reasonable population here, though it wasn’t obvious what it’s breeding on (I didn’t note and Wild Strawberry).  A fresh Dingy Skipper male too.  Also, 7 Peacock, 1 Small Tortoiseshell and 5 wandering Brimstone males.  Strangely, nothing in the lane leading up from Ramsdean.

I also spent 45 mins wandering along the north-facing slope of Ramsdean Down, but didn’t get anything like as far as Rakefield Hanger and Little Butser.  There are apparently small colonies of Duke of Burgundy dotted all along the slope bottoms here, right up to the cross dykes above Little Butser.  On my way out I met Mark Bridges who had just visited Little Butser and seen precious little, and no Duke of Burgundy.  Ramsdean also has a low rabbit population (Little Butser is still rabbit country) but there is much constipated rank F rubra turf with a lowish herb content.  Good cowslips etc, often amongst rather ruderals vegetation along the lower slopes.  I saw only the odd Peacock here. 

I finished the day with an hour or so in and around the delightful Bo Peep Copse, which I discovered back in 1976.  It has a wonderful flora, with much Solomon’s seal and patches of Herb Paris amongst the bluebells.  Also, moschatel, sanicle, yellow archangel and goldilocks, and some tall flowering cherries.  The western end was coppice ca 3-5 years back and is regrowing strongly.  The little pond is delightful still, with a healthy population of small rudd and evidently not too many carp.  Various Orange Tip, Green-veined White and Brimstone wandering around here. 

His Grace at Rodborough Common, Cotswolds

Two males were seen in the main territory at Rodborough Common, near Stroud, yesterday, May 3rd.  These were the first sightings there this year, and I think the first in the Cotswolds.  Today was a little too windy there and only a single male was seen.  I checked two other Rodborough colonies without success.

I have an accurate set of records of His Grace's appearance at the main Rodborough site (Manor Spur) since 1993 (earliest and latest dates are in italics):

1993                     1994                     1995                    1996                     1997                1998                 
28th April             2nd May                14th April           7th May                21st April        25th April        

1999                     2000                     2001                     2002                     2003                    
24th April             27th April             5th May               21st April             15th April

2004                     2005                     2006                     2007                     2008
2nd May                30th April             1st May               16th April            27th April
(?26/4)                                                                                                         (?26th)

2009                     2010                     2011                     2012                     2013
20th April             23rd April             9th April              12th April             3rd May

So, this is the third latest the butterfly has appeared here, after 7/5/1996 and 5/5/2001.  It's been out in April here in at least 15 of those 21 years. 

I have a much longer data set for the start of the flight season at Noar Hill, Selborne, running back to the long hot summer of 1976.  That data really does show that the butterfly's season there is getting earlier and earlier.  Of course, what I don't have is such good information on the last sightings of the year...

First of the year

I have been keeping an eye on the weather and paying short visits to Butser Hill over the last couple of weeks to search for Grizzled skippers. The south facing slopes here warm up very quickly and normally produce at this time of the year once we have had a couple of days of reasonable weather . I have found that Dukes normally appear here about 5/7 days after the first grizzly.
However it would seem that the earliest site in Hampshire is normally Noar Hill. So having seen a solitary Grizzled Skipper at Butser on Sunday and seeing the weather forecast for the first few days of the week were good I pencilled in a trip to Noar Hill on Wednesday.
As I travelled up theA3 the Hampshire Hangers looked like it was still winter with virtually no leaves on the beech trees whatsoever. However it was warm and sunny which was a bonus.
As I worked my way through the ancient pits at Noar Hill it was very warm in the sheltered micro climates of each bowl and reinforced why this is such a diverse site for flora and fauna. It always makes me smile when I visit Noar Hill to think that it is a man made site formed as a result of medieval chalk digging - imagine the furore such a proposal would cause now!
Butterflies were out and about in force and numbers of peacock, brimstone and orange tip were noted when I caught my first, if brief, sight of a Duke as it disappeared over the rim of one of the pits - result!
This focused my searching and shortly after I located another individual in an adjecent pit which appeared freshly emerged and still rather weak in flight. It gave a good photo opportunity but I then left it in peace to conserve its energy for the battles with other males which would inevitably lay ahead over the coming days.
I have earmarked a number of areas to explore over the weekend - some I know and some are new to me - one or two are just 'prospects' with no form known to me. With the weather looking good hopefully the outcome will be positive.