Saturday 9 July 2016

Butterfly Chronicles July 2016

Tuesday  Oakley Wood  Oxfordshire/Buckinghamshire/ border

This time of year is the quiet time for birding so I turn to my other great interest, butterflies, which conveniently reach their peak of activity just as the birding wanes.

The woods are quiet now, little bird song permeates the luxurious leafiness of wood and hedgerow, perhaps the odd Chiffchaff sings desultorily and briefly but then falls silent. The occasional call from some invisible avian fledgling hidden in the depths of the vegetation is all that stirs the gentle silence or the shadow of a bird hurrying across the tree tops. Many adult birds are beginning to moult and have become  secretive and hidden for the most part whilst birds born this year feed silently and unobtrusively in the tree tops, making the most of this time of plenty.

Butterflies, when the weather is appropriate, which this year is sadly at a premium, now come to prominence, showing themselves in all their delightful variety of patterns and colours. No hiding away for them but for many a brazen, short lived display of hyperactivity is their modus operandi as they hasten to mate, lay eggs and then die in an all too short lifespan of days.

Not all butterflies are so obvious however, some are secretive, small and elusive and have to be sought out, often requiring much patience and offering no guarantee of success. So it was that on a Tuesday afternoon of sunshine  I drove to a much loved location, Oakley Wood, part of the former Royal Forest of Bernwood, which centuries ago covered 400sq km across the Oxfordshire/Buckinghamshire border and was protected in one form or another since Norman Times so that kings could hunt wild boar and deer. Those days are long gone now, although the deer remain but the kings have been supplanted by dog walkers, butterfly and birding enthusiasts like myself and people coming to enjoy some peace and tranquillity. Only a few remnants of the once vast forest now remain, marooned as islands of woodland and meadow in a landscape of farmland, housing developments, busy roads and all the complex infrastructure of our modern world. Nonetheless they still manage to impart an echo of times past, a sense of permanence that brings an inner peace in this frenetic world. BBOWT (Berks, Bucks and Oxon Wildlife Trust) manage five reserves within the former confines of the Bernwood Forest seeking to protect and enhance for the benefit of future generations the mosaic of woodland, species rich hay meadows and hedgerows  that still remain.

Oakley Wood is one of these and I went there at lunchtime to try my luck at finding what is for me the ultimate in British butterflies, a Purple Emperor. I was a little too late though as by afternoon the emperors here generally retreat to the security of the top of the oak trees. I was not too downhearted as by just being here I could at least nurture the hope that something good would come my way and it surely did.

As I walked down the main track through the woods I met Chris who was looking at a Black Hairstreak footling around in the grass by the cinder track. Black Hairstreaks are very hard to see at any time, in fact are rare and usually restricted to stands of blackthorn, which at this precise location were conspicuous by their absence. So what on earth was this tiny tissue paper light butterfly doing here? We were baffled by its presence but accepted this unexpected gift and made the most of it. The butterfly itself was in good condition and showed little sign of wear so presumably was not long emerged into this world, which again was puzzling as early July is coming to the end of its flight period. It fiddled around on the blades of grass for ten minutes or so and then flew up and disappeared into the dark green leaves of a nearby oak tree.

Black  Hairstreak
We walked further down the track and a White Admiral, surely the most graceful of our butterflies, floated like some ethereal apparition over some bramble flowers before coming to rest. They seem to flit between invisibility and visibility, an optical illusion created by the way they fly on horizontal black and white wings. To my mind their underwings are the most beautifully patterned of any of our native butterflies, surpassing even the supreme Purple Emperor.

                                                       White Admiral
I left Chris and returned in quiet contemplation along the track heading for the car park and home. 

Many butterflies were still on the wing as I meandered along, Marbled Whites, dull brown Ringlets, the colour of the ground they so covet, Large Skippers, feisty and restless and even a Red Admiral sunning itself on the track, enlivened my walk back. 

Marbled White
Large Skipper
Red Admiral
I stopped by the pond, forever muddied and trashed by dogs who find the water irresistible but despite the intermittent disturbance from the passing dogs, it was, as it is every year, energetically patrolled by a Broad bodied Chaser, clinging precariously to a twig, his huge dark eyes swivelling independently, alien, like some mechanical toy, with wings held like draped, veined cellophane flags to absorb the sun. 

Broad bodied Chaser
The sun was becoming weaker now as more cloud slid across the sky but the air was warm. I met a couple walking their dog and the lady held something in her closed hand. She held out her hand, opened it and gently enquired of me what was it she was holding. It was a caterpillar. A chipolata shaped, three inch emerald green caterpillar with black bands and gold hairy warts forming rings around its gently pulsating body. It was none other than the larva of an Emperor Moth.

Emperor Moth larva
She had 'rescued' it as it was crossing the track and I diplomatically suggested it would be best to put it down in the grass by the track preferably on the side it had been heading towards. We left it busily working its way  along a grass stem and seeking whatever it was heading for before being intercepted by the well meaning lady  

Common Spotted Orchids

Wednesday  Silchester Common  Hampshire

I went here with Peter on a pre-arranged day out to look for butterflies. Silchester Common is yet another delightful little reserve tucked away discreetly and which we accessed by a small upmarket car lot containing mainly vintage Mercedes.

Once through the entrance gate we skirted a small pond, followed a track through some bushes and trees and came out onto an open area of short, rabbit nibbled grass with scattered gorse bushes and clumps of bell heather. We were searching for Silver studded Blues and it took very little time before we located a couple of the blue males, fluttering with rapid wing beats, in wavering flight, low across the grass and heather.

Silver studded Blue-male
The butterflies seemed to be constrained from wandering very far, remaining in just this very small area of heathland. The majority were males, endlessly moving from heather clump to heather clump, settling on cerise pink heather flowers before flying off again, never still for more than a few moments.  Being constricted to such a small area it was inevitable that males would meet and when they did they would go into a low level whirl of blue, spiralling and circling around each other for a few seconds before breaking off and following their individual flightpaths 

The males were bright blue suffused with violet on their uppersides with narrow white fringes around both fore and hindwings and showed the typical 'blue butterflies' intricate patterning of spots on the silvery underwings. The blue was not complete over the wings as pale brown edges and suffusions infiltrated the blue and I noticed that the intensity and amount of blue on the individual males I encountered could vary considerably. There were quite a few males fluttering over this small area of heathland where the colony had established itself but Peter said there would be many more in the next few days which should be quite a sight.

I followed various males as they flew in front of me looking for a female but it became apparent the males vastly outnumbered females and in the end I only found two females, compared to around thirty males. The females were dull brown and looked slightly smaller with only a row of indistinct orange spots on their hindwings as a relief from their overall nondescript brown colouration. 

Silver studded Blue-female
A male and female met on a heather flower and commenced an interaction that veered from mild antagonism to courtship, the female clinging to the flower her wings firmly closed while the male fluttered excitedly with wings open clinging to the same flower but then the female rejected his buffeting and fluttered violently against his advances but he persisted, resulting in the female closing her wings again but quivering them as if in solicitation. Just when I thought they were going to mate they broke apart and flew their separate ways.

Happy at our encounter with this delicate, unassuming little butterfly we made our way back to the car.

Wednesday  Chazey Heath Oxfordshire

Having had virtually instantaneous success in locating the Silver studded Blues of Silchester Common we decided we had time to chance our arm and head for The Packsaddle Pub at Chazey Heath which was, with a slight diversion, on our way back to Oxford.

Our target this time were White letter Hairstreaks which would undoubtedly prove much more of a challenge to see than the blues. It was also getting late in the afternoon and I was none too certain that the hairstreaks would be active.

The Packsaddle Pub is tucked just off the main road and has a slip road running behind it  with sapling elms on one side and a low hawthorn hedge overrun by brambles on the other. 

The hedge with the hidden road and elms behind it
The hairstreaks spend most of their time in the top of the elms, the only tree they will live in and if you are very lucky individuals will come down to nectar on the bramble flowers in the hedge below. Peter and myself went our separate ways, Peter checking the elms and me the brambles but I was not surprised when I failed to find any sign of a White letter Hairstreak in the brambles but Peter after about thirty minutes managed to see one briefly, flying at the top of an elm. We stood, awaited developments and sure enough the hairstreak was seen again but only briefly, flying at the top of the same elm and then made sporadic appearances for the next twenty minutes and on one occasion there were two spiralling around each other. It was hardly satisfactory, as a tiny butterfly, flying for a few seconds above a thirty foot elm was, even through binoculars just a featureless microdot in the sky. Resigned to maybe this was the best we would get we stood and watched the elm for another sighting, working on the principle that at least we had seen one or two, albeit not very well.

Slightly bored with waiting I turned to look at the adjacent hawthorn hedge and the delicately mauve tinged, white bramble flowers on top of it and there was the little brown triangular shape of a White letter Hairstreak examining a bramble flower! Every time I encounter such a situation a frisson of excitement takes hold of me. It only occurs when I find a hairstreak and probably derives from the knowledge that a very elusive and difficult butterfly to find has finally given itself up to my hopes and aspirations.

White letter Hairstreak
I pointed it out to Peter and we set about taking images of the hairstreak feeding unconcernedly at eye level. A little battered on one wing but that was of no worry to me although Peter gently complained that it was not so good  for pictures as far as he was concerned. We watched it for around ten minutes before a van drove fast down the narrow slip road between the hedge and the elms and the butterfly took fright at this intrusion, flying high into an elm on the opposite side of the road. It was gone and I inwardly cursed the unwitting driver.

We waited for some minutes and saw the hairstreak flying above the elm but it showed no signs of coming back to the brambles. After a further thirty minutes an idea came to me. We were right next to a pub, a nice pub that was open, with a nice garden on a warm and sunny late afternoon. 'C'mon Peter let's go and have a drink. You never know it may come down from the elm and be waiting for us here when we come back.' It was of course one of those quite ridiculous flippant things you say more in hope and expectation, almost in jest, never dreaming it could happen.

Yes, I know, you have guessed already. After a relaxing drink in the pub garden we got up to leave for home. Peter went to the car whilst I said 'I am just going to check the hedge.You never know!' I walked the few metres back to the hedge and there to my amazement and delight sat a White letter Hairstreak, the now familiar brown triangle of closed, paper thin, brown wings standing proud on a bramble flower. I called in excitement to Peter and we set about reliving and enjoying the spectacle of an hour or so ago that was so abruptly interrupted by the speeding van. It was the same hairstreak we had seen on the bramble flowers before as there was a distinctive notch out of one of its forewings. I just stood in admiration as it perambulated over each flower, methodically examining and probing before moving to another flower. The diagnostic white W was a little faded on this individual but that was of little consequence as it was just such a joy to see and this time no cars came along to disturb it. 

Another butterfly enthusiast rushed up to us. Where did he come from? He excitedly commenced taking images of the hairstreak,  Both Peter and myself felt a slight resentment at this, a natural reaction I guess. This was 'our' hairstreak, we had planned and worked hard for this reward. Of course we said nothing and after some half an hour the hairstreak flew back up to the elm. We walked back to the car and an airborne female Stag  Beetle, stooging crazily  across the tarmac at a low level collided with my trouser leg and clung on for dear life. I removed it from my leg and gently placed it by a flower bed to take its photo. It has been years since I have seen one and they are now, like many natural things becoming ever more scarce as their habitat is lost, so before we left I made sure it was secure and hidden amongst the flowers. 

Female Stag Beetle

Thursday  Finemere Wood  Buckinghamshire

Although the weather looked none too good I had arranged with Peter to meet him at Finemere Wood at 10am. Finemere Wood is another part of the now fragmented and historic Bernwood Forest, managed by BBOWT and is a notable butterfly site and of great interest to me as it is as good a place as any to see Purple Emperors.

I duly arrived at the appointed hour only to find Peter was going to be an hour late but this gave me time to find my bearings in a place that I had never visited before. Finemere Wood has one fairly short main ride running through it and is considerably smaller in size than Oakley and Shabbington Woods, my usual haunt for seeking out Purple Emperors and other butterflies. I walked down the long track from the road to the Reserve and into the wood just as the sun broke through the grey clouds.

The main ride through FinemereWood looking back to where
the Purple Emperor flew down to delight us all
Silver washed Fritillaries were very conspicuous, flying at great speed along the sides of the ride and occasionally settling to reveal their orange uppersides and delicate green and white markings on the underwings. 

Silver washed Fritillary - female
Marbled Whites, Ringlets, Large Skippers and Meadow Brown butterflies were conspicuous, settling at any opportunity on the bare parts of the ride, with wings wide open to absorb as much of the intermittent sun as possible. A couple of White Admirals briefly glided through the trees and were gone as quickly as they arrived. I walked to the end of the ride but saw no  sign of a Purple Emperor although the combination of Oaks and Sallows by the ride, the two requisite plants for Emperors, looked excellent habitat.

A Common Lizard cautiously ventured out onto a dilapidated wooden bench to warm itself as I turned to walk back down the main ride.

I met Peter at the other end who gave me the unwelcome news that he had just seen a Purple Emperor flying about at the entrance gate to the Reserve. Feeling a little slighted I congratulated him through gritted teeth as he showed me where it had been flying around. We stood here for a while but the Emperor did not return and we walked a little way back up the ride. A man and his dog came up the ride from the entrance gate and chatting to him we learnt that he too had seen a Purple Emperor just a few moments ago roughly where Peter had seen his. By now I was beginning to recognise the first onset of paranoia. It seemed everyone was seeing Purple Emperors apart from me.

Peter, probably tiring of my complaining about the injustices of fate walked off along a side path from the main ride in search of a reported Black Hairstreak  but I remained in the vicinity of the entrance gate in the forlorn hope that the Purple Emperor, might, just might return and settle on the ground as they are wont to do on occasions. Some hope!

The man  and his dog returned back down the ride and we chatted some more whilst I discreetly kept an eye on the ground in the vicinity of the entrance gate some 100m distant. A large dark shape flew erratically around the gate. I got excited but it was a Red Admiral which eventually settled on the track but just as it did another even larger butterfly flew a similar erratic course low over the ground, circled around a couple of times and then settled right by the Red Admiral. I checked through my binoculars. It had to be. A Purple Emperor! Excusing myself, I interrupted our conversation and made haste down the ride to the entrance gate closely followed by the man and his dog.

There on the ground was the most beautiful sight any butterfly enthusiast could wish for in the form of a glorious male Purple Emperor sucking up through its yellow proboscis salts and minerals from the path. The sun had gone in so at first there was little sign of its crowning glory, the imperial blue iridescence on the upper surface of its wings, when seen from certain angles. At the moment we were looking at a dark brown almost black butterfly with prominent white markings on its wings and two orange rings imitating eyes at the bottom of the hindwings.

The emperor then shut its wings showing the large eye spot and the lovely black, brown, grey and white marbled patterning on its underwings.

It kept its wings closed until the sun stole up the path and then opened them and there in all its startling beauty was the blue on the wings which seems to change in intensity and colour depending on the light and angle at which the wings are held. Sometimes it is dark blue, then at other times it takes on a shade of blue shot with undertones of violet 

It can almost take your breath away such is its beauty and magnificence. As you watch, tantalisingly the colouring fades to dark brown as the butterfly moves position, or becomes darker blue and less distinct, but then another movement will bring back that sensational colour, sharply defined and of a depth and intensity it is impossible to adequately describe. This is the glory of this magnificent insect, arguably for me the supreme butterfly in Britain today, and any day and any year come to think of it.

It remained on the ground for a good twenty minutes, giving time for two other late arriving enthusiasts to see it. One of these had never seen one before and at first enquired of us if it was a Red Admiral! 'Oh no' we chorused. 'This is a Purple Emperor and you are very lucky. Enjoy it while you can.' And he did. We all did.

We  decided that we could do no better and left Finemere Wood, walking back along the approach track to the road and our parked cars, passing a herd of gently curious cows gathered at the fence to watch our passing.

Friday  Oakley Wood  /Oxfordshire/Buckinghamshireborder

Having seen my first Purple Emperor of the year at Finemere Wood yesterday, I was keen to see more, well who wouldn't be, so I decided to return to more familiar surroundings today and  make another visit to Oakley Wood. The main track through here is a well known hotspot for Purple Emperors but the weather forecast did not make good reading. Grey cloud was forecast but with a window  of opportunity of an hour, from around twelve noon, when it was predicted there would be sunny intervals.

I decided to take a chance and so arrived at Oakley Wood at around noon and made my way to the main track. I was on my own and stationed myself in a spot I considered would give me a good opportunity to see up and down a fair amount of  the track. The idea being that Purple Emperors are prone to descending to the track to pick up trace minerals and salts and if I could look up and down the track I would see any Emperor that decided to come down from the Oaks lining each side of the track.

Ar first the weather remained grey, dull and frankly depressing with my wondering had I made the right decision to come here. I stood quietly as various dog walkers passed me and waited for the sun to appear. After thirty minutes the sun came out and I felt a little better about things as yet another couple with a dog came towards me and then stopped to ask me what I was looking for. I told them about the Purple Emperors and they wished me luck and said how much they would like to see one too. They walked on about a hundred metres and as I looked at their departing figures a large dark butterfly flew in a distinctive, powerful and exaggerated, swooping, tilting flight around them and their dog. They stopped and the butterfly landed at their feet. It could be nothing else of course. It was a Purple Emperor. No other butterfly would show such fearlessness.

The purple iridescence only shows at certain angles -see below!
They waved to me and I acknowledged them and jogged down the track to join them. They, like everyone else before were thrilled to see it, almost in awe of its beauty and thoughtfully held their dog on the lead whilst I took photos of  the emperor. All of us were so delighted by this fortuitous event. At this precise moment a range of emotions pass through you. Pleasure? No, more than that. Sheer delight.  
However, tempered with the satisfaction that you have seen an Emperor comes the ever present anxiety that it will not remain and will fly off never to be seen again. You want more and more and hope it will stay. Some do. Some don't. If they find a good supply of minerals nothing will move them and they will remain for a very long time but if there is not much for them to feed on they become restless and will often just return to the trees

The emperor flew up and around us and I hoped and prayed it was not going to leave us so soon and with a few regal glides and flicks of its broad wings it swooped around us and then down onto the track again, to resume probing for nutrients. The dog walking couple said they would leave me to it and so for the next twenty minutes, alone, I paid homage to the emperor as it flew low, back and fore along the track looking for more mineral deposits to absorb through its yellow proboscis. It must have landed and taken off at least five times, increasing my anxiety levels each time but in between its brief excursions remained settled  long enough for me to get as many images as I desired.

At one stage it was virtually at my feet as it walked around looking for the minerals and salts it craved, dismissive of the scurrying ants fussing around it and disturbed by its presence. 

Looking down on the 'Emperor'
A lady jogger came down the track accompanied by her partner on a bike. I waved at her asking her to stop but she ignored me and carried on running, coming closer and closer to the Emperor. The butterfly remained feeding on the track. Oh no, she is surely going to crush it as she was on a direct course for the butterfly. At the very last moment the Emperor flew up before imminent disaster struck it, circled the jogger and settled once more on the precise spot it had been disturbed from. The jogger's partner apologised on her behalf and said she had headphones on so did not hear me. However I presume she was not blind and must have seen me waving to her to stop or at least have the consideration to divert her progress. In fairness this was the exception as most people, be they dog walkers or whoever, usually show much more consideration and are very interested and delighted to see a Purple Emperor

Lift off!
Purple Emperors impart an air of regal indifference and superiority, almost a swagger about them especially when parading about on the track with wings held out in a distinctive V shape. 

Only the males possess the blue iridescence and usually it is only the males that descend to the ground to seek out minerals whilst  the slightly larger female remains in the tree tops feeding on aphid honeydew. The ultimate in photos is to get an image where both wings show the purple blue but it is very difficult. To my delight I managed it today but only when the emperor was facing me otherwise it was the usual purple on one wing and dark brown on the other.

Males can and do fly up to a thousand metres to a so called master tree, usually an Oak where they compete with other males for a female's attention. Formerly they were found in England as far north as the Humber and also in Wales but they have declined due to habitat loss and are now extinct in Wales and restricted in England to central and southern counties. Everywhere that they do occur they are present in low densities and are usually elusive with mid morning being the best time to encounter them

Many words have been written about the Purple Emperor and they have been given names which reflect the respect in which they have been held such as His Imperial Majesty or my favourite, Sultan of Morocco which imparts a deserved air of mystique and esteem to them.

The final sight of the Purple Emperor was as it scrambled around in some grass still seeking sustenance but it was not content with what it found and with a flick of its wings headed back up into the Oaks

After this delightful encounter I waited in the hope of seeing another land on the track but it was not to be. I walked to the car park and there examining the tyres of the parked vehicles was another Purple Emperor. It flew around, restless and searching, then landed briefly in the dust and dead leaves at the edge of the car park but, dissatisfied, it flew up, circled me twice and then ascended into the Oaks and was gone.

1 comment:

  1. hi Ewan, I suspect your dragonfly at Bernwood is a Broad-bodied Chaser, because if the dark bases to the wings. When I was there, there were both male and female present, and there was no doubt over her ID. Glad to see you got plenty of good PE pics. Mike