Wednesday, 13 June 2018

A Black Hairstreak Bonanza 11th June 2018

Black Hairstreaks are very rare butterfly and easily the rarest of the five species of hairstreaks that inhabit Britain. They are restricted to a small area of low lying clay in the Midlands of England extending across only three counties, Northamptonshire through Buckinghamshire to Oxfordshire.

They are much sought after by butterfly enthusiasts who will travel considerable distances to see them due to their great rarity, their short flight season which is for only a few weeks in June and July, and also due to their very restricted range from which they will not move. Not only that but when you do find a colony of this tiny butterfly it can often only encompass a very small area of literally a few hundred metres.

This year, early reports of large numbers of Black Hairstreaks being seen at their traditional sites indicated they were having an exceptional year, and the recent spells of good weather seem to have resulted in them being on the wing earlier than their usual time, which is the latter part of June and early July.

Last year I was fortunate enough to find a colony at a little publicised site and managed to see about half a dozen flitting around their favoured blackthorn bushes and nectaring on the wild privet that grew amongst the blackthorn. I kept this information at the back of my mind and vowed to make another visit this year.

Living, as I do, in Oxfordshire I did not have to travel too far to the site and waking to another wonderful day of sunshine and warmth in what is now the height of summer I made a plan to go in search of some Black Hairstreaks.

The journey took about forty five minutes and I was soon parking at the side of a quiet country road and entering a small and superficially unremarkable area of blackthorn and wild privet adjacent to the road. 

I had no idea what to expect as I was unsure of my timing. Would I be too early? Would the wild privet still not be in flower? Would there be a long wait, as is often the case, to see a Black Hairstreak? I would consider myself lucky to see just one.

I turned onto the narrow path alongside the hedgerow and immediately saw what I was looking for. A small brown triangle, formed by the closed wings of a tiny butterfly. A sight that always brings a special thrill to me when first encountered.

A Black Hairstreak was nectaring on some wild privet growing up amongst a small hawthorn tree. 

As it fluttered from each small pyramid of white flowers to the next, it disturbed others of its kind until I had seen at least four, possibly more, it was hard to tell, jinking up and down in their characteristic jerky flight.  This was beyond all my expectations and for a moment I just rejoiced in my good fortune standing amongst the surrounding lush vegetation of high summer, as a gentle summer breeze blew through the trees above me, creating eddies of warmth, scented by the wild privet, along the secluded, sun dappled path before me .

I thought I was entirely alone but then Peter appeared along the path. We greeted each other and I told him about the hairstreaks I had just seen in the bush beside us but he told me that there was far better further down the path, where he had been photographing at least four Black Hairstreaks, literally at shoulder height, nectaring avidly on their beloved wild privet. I followed him down the narrow path, the sun now becoming increasingly warm in this enclosed area.

Sure enough when we got to the bush he had in mind, there were the Black Hairstreaks, feeding on the privet flowers. 

This wild privet bush had at least four Black Hairstreaks
nectaring on its flowers
Black Hairstreaks are well known for being very amenable to close approach and never seem too bothered by such as us who wish to take their photograph. Even if they feel disturbed and intruded upon they just flutter around for a few seconds before resuming nectaring on their favourite flowers and so I too got some outstanding close up images.You could hardly fail.

We stood here for a while and just enjoyed this special moment as the hairstreaks carried on their brief lives, blissfully ignorant of the delight they were giving us.They were in pristine condition, showing little signs of wear, so presumably had only recently hatched. Some would have it, that apart from their great rarity they are drab and uninteresting, appearing an unremarkable dull brown but  I would disagree. Look closely and you will see not a black but a mainly mouse brown butterfly, bearing a lovely narrow orange band running along the outer edge of, especially, the hindwings, with a tiny row of black dots encompassed within the orange band. Also visible on the underwings is a fine white line in an inverted shallow W shape across both the upper and lower wing from whence the name hairstreak comes.The lower hindwings also each have a minute black spur tipped with white.

The butterfly is not without charm either as it conscientiously inspects each small waxy white flower, delicately walking across the flowers, on legs banded alternately black and white, lowering similar banded antennae to inspect each flower and probing any open flower for the nectar with its thread thin black proboscis. They can remain on a flower pyramid for quite some time, examining each and every flower, always with wings firmly closed, walking with equal ease underneath and around the pyramid of flowers as well as on the top. Often, when they are face on, they virtually disappear as they are so small and the closed wings are wafer thin in appearance when seen this way and it is only when they turn side on that you realise they are still present. Fortunately they are rarely still for more than a few seconds, so the oversight is soon rectified by the butterfly itself as it wanders around on the flowers. Once satisfied they have examined and fed from every possible flower they then flutter onto the next pyramid of flowers to repeat the whole process.Watch them closely for a minute or more and soon the wider world drifts away and you too are in their micro world of sunshine and white privet flowers.

Peter had already been here for some time before my arrival so departed, leaving me to myself and I saw no one else for the next two hours. I wandered the path back and fore rejoicing in the abundance of this small butterfly. It is not often that you can say Black Hairstreaks are the commonest butterfly present in any location but here, today, that was very much the case. They were easily into double figures along the path. Speckled Woods were the only other butterflies inhabiting the ride, basking in the sun and warmth and flying up from my approach.

I spent an hour or more wandering up and down the path marvelling at all the insect life that was around me. Many strange insects were sharing this habitat with the butterflies although for me it was an impossibility to identify them but nonetheless I could enjoy their many and varied forms.

I had found Black Hairstreaks on almost every privet bush along the path and happy with a surfeit of photos stood back and enjoyed simply watching them, knowing that a day like this would be hard to repeat.

Eventually I grew tired of wandering the path so went back to its beginning and turned left onto another more substantial track running further away from the road into the bushes and trees. This track was surrounded on each side by blackthorn in abundance with open glades, scattered small oaks and taller trees. It was a delight, sunny, secluded and deserted, apart from myself. I followed the path further and found yet more hairstreaks fluttering around the blackthorns. They appeared to be mainly males searching for females. They were constantly on the move, flying around and amongst the twigs and leaves of the blackthorn but every so often they would stop on an oak leaf, always with closed wings inclined towards the sun, but only for seconds would they remain motionless, before they were off again in their incessant search for a female. The numbers were truly incredible, their tiny brown, fluttering forms appearing everywhere. I tried to count them accurately, and although it was difficult I reached a total of thirty nine which meant there were probably at least double that number present. And this without leaving the main track.There must have been many more, unseen, further into the bushes.

I counted up to forty Black Hairstreaks from along this track
The heat of midday was still increasing and so was the butterfly activity if that were possible. In the end I stopped on the track and as on the path by the road, earlier,  stood and enjoyed the sight of so many Black Hairstreaks coming and going around me.

Then it happened. I was watching a Black Hairstreak fluttering low down by the side of the path and it encountered another, brighter looking, individual. They started to spiral around each other, an activity which I was becoming used to as there were so many males flying around, they inevitably came into brief conflict when they met. This however was different as the spiralling lasted less than a few seconds before they settled side by side on a hazel leaf and in a second, so quick you could have missed it, they reversed into each other and joined their bodies end to end. A male and a female mating and I was there to witness it right from the start!

Black Hairstreaks just prior to mating
The female is the brighter of the two

Mating Black Hairstreaks
They dropped from the leaf onto a blade of grass below and I watched as the female moved up the blade of grass with the male firmly attached. I took some photographs but the surrounding grass stems created annoying shadows and so I delicately tried to move the offending grass stems away so I could get a clear shot but before I could do anything about the offending grass the pair walked onto my arm. Unbelievable. 

Mating Black Hairstreaks on my arm!
I got my phone out and took a couple of images but was keen that the pair should be returned to a more  normal environment to carry on their tryst. I lowered my arm to brush the grass stems and with a little prompting they resumed their perch on the grass.

I continued watching to ensure all was well but another male discovered the couple and energetically tried to muscle in on the action, fluttering around the conjoined pair, buffeting them in his frenzy but getting absolutely nowhere. He was, however, very persistent and would not give up and even settled on the mating pair, creating a classic menage a trois but it was a hopeless cause, he was too late. Eventually the extra male gave up with his unwelcome attentions and flew off but soon he was back to make yet another attempt  at mating with the female but was just as resolutely rebuffed as before.

The mating Black Hairstreaks plus the troublesome
second male Black Hairstreak
Half an hour passed and the mating couple remained in situ in the grass. Content they were comparatively safe from harm I walked on and coming back half an hour later found they had moved up into a nearby blackthorn, still joined body to body. I have no idea how long they remain conjoined and although I waited for some time they showed no signs of separating.

Mating Black Hairstreaks with the female upper
and the male lower
I left them and walked a little further to another open area, finding at least another half dozen Black Hairstreaks fluttering through and around a large blackthorn clump. Others were settled on the broader oak leaves, either sucking up honeydew or basking in the sun. As I stood there a much larger butterfly glided above my head on stiff wings, a brief impression of black and white, its flight powerful and incredibly graceful. It disappeared behind some small oaks only to re-appear and settle on an oak leaf.

It was a White Admiral. My first of this year. Again, like the Black Hairstreaks, pristine and obviously recently hatched, maybe even this morning. It perched facing the sunlight, surveying the open glade before it. Their underwing patterning is breathtakingly beautiful and for a minute it was right here in front of me before being disturbed by a passing insect and took to the air not to be seen again

White Admiral
It was now approaching two pm with the heat of the day burgeoning and it was becoming apparent that many more butterflies were on the wing. A couple of Brimstones settled on some Marsh Thistles to imbibe the nectar, while Meadow Browns and Speckled Woods were, by now, almost commonplace. Finally a Large Skipper settled on a grass blade to soak up the  sun.

Male Brimstone
Speckled Wood
I remained for another hour, relishing this unforgettable experience with the Black Hairstreaks and even when I returned to the car, and stood by the road, there were at least half a dozen Black Hairstreaks feeding on some wild privet right by the car.

I know I will go back but I also know it will never be as good as it was today. A truly unforgettable experience, especially to witness Black Hairstreaks mating and one I feel so privileged to have witnessed.

Please click on any of the above images to view a larger version