Saturday 5 August 2017

Otmoor Cameos 4th August 2017

I decided to spend a morning at the RSPB's reserve at Otmoor as the forecast was for sun and little cloud. I got there reasonably early, at 7am, but was surprised to find I had the place to myself as normally someone always seems to beat me to be the first visitor of the day. 

The summer is slowly progressing towards autumn and the first signs are beginning to show as the hawthorns are already full of red berries, whilst many blackberries, where the sun is trapped in sheltered corners, are now almost fully ripe. Dusty blue sloes cluster like weird growths on the thin stems of blackthorn. They seem early this year and it will not be more than a month or so before I pick some to make Sloe Gin.

There is still some colour in the ditches and on wayside banks, courtesy of the cerise pink flowers of Great Willow Herb and the paler purple flowers of Creeping and Marsh Thistle. The flamboyant large white trumpets of Great Bindweed scramble across hedges and the flat yellow heads of Fleabane and Catsears shine amongst a buff sea of tall seeding grasses.

The reedbeds are green and dense, the countless, chitinous and pointed leaves, held on stiff stems making a soothing sussuration of sound as they are disturbed by the wind and rub one against another.

Turtle Doves

The Turtle Doves are still here on Otmoor. This morning in the early light one was perched on the telephone wire beside the approach track to the bridleway, backlit by the early morning sun. I see one or more every time I visit and it is hard not to take them for granted because of this familiarity. Then I ponder that it may not be for much longer that they return each year to Otmoor as the predictions for their future as a species inhabiting Britain are dire.Their population has dropped by over ninety percent in Britain since 1970 and they are predicted to be extinct in Britain in four years. Yes, only four years. It is heartbreaking and I hope that the prediction proves untrue although I am probably grasping at a straw in the wind.

So I enjoy them whilst I can and feel privileged that they are still accessible so near to my home.They are such a pretty bird, their plumage an amalgam of pleasing pastel colours, from their pale grey head with a badge of black and white 'sergeant major' stripes on either side of their neck to a breast of pink purple and upperparts patterned by black centred feathers fringed rust brown, giving them that scaled look, so reminiscent of a turtle shell and from whence their name originates. 

Later I saw a male fly down to perch on the cattle pens. I could see him watching me and it was touch and go if he would take alarm at my presence or fly down to the ground to pick up the seed daily scattered here for them. I stood stock still and we watched each other, both of us gaining confidence, he to fly down to feed. and me to edge slowly forward. He looked up. I stopped and so it went on until I was leaning on the metal gate not more than a few metres from him. Considering how much they are hunted in Mediterranean countries it is remarkable how confiding they can be on Otmoor. I wonder if this is a general trait for the species and if so, can that make them easy victims to the men with shotguns awaiting them beyond these shores?

Relaxed now and re-assured by a nearby family of fully grown Mallards, feeding on the grain and showing no alarm at my presence, he shuffled across the ground picking at the seed. So long as the Mallards were content so was he but if they became wary so did he, and with neck raised was ready to flee at any second. For ten minutes he fed and then flew up onto the wire and commenced his gentle purring song.

Reed Warblers

Otmoor's reedbeds currently harbour many Reed Warblers, some still nesting or with newly fledged young that remain hidden, deep in the reed stems, tended by their parents until they become independent. The scratchy hesitant song of the males has long since ceased and now the adults hidden presence in the reeds is betrayed by their churring alarm calls or the grating calls of their recently fledged young. Many young birds from earlier broods are now fending for themselves and they find their way out of the reeds and into the hawthorn hedges to hunt insects. These juvenile Reed Warblers can be told by their fresh plumage, their flight feathers looking immaculate and without the fraying and wear that their parent's plumage shows after a hard season raising their young.The adults will moult into fresh plumage when they get to their winter quarters in tropical Africa.

Note the fresh wing and tail feathers

Juvenile Reed Warbler
I watched a recently independent young Reed Warbler hunting insects in a hawthorn, methodically covering every part of the tree, acrobatically and diligently examining the underside of every leaf for prey. Unremarkable  in its rich brown and buff plumage it was still attractive in its own understated way. Soon enough it will feed up and gain weight by  accumulating subcutaneous fat to sustain it on its long migration to tropical Africa but for now it was free to enjoy the proliferation of insect life and have, if ever such a thing can be said of a wild bird, a comparatively easy time of it. In another month they will embark on a hazardous journey to cross the Sahara and fly onwards to spend the winter in central and western parts of tropical Africa. Many will perish and only a comparative few will return to breed. 

Green Woodpeckers

A maniacal cry alerted me to the presence of a young Green Woodpecker, the largest of our native woodpeckers and looking around I saw the distinctive bulky shape of a woodpecker coming across Greenaways in a rapid, bounding flight, swooping upwards to alight on a dead spike of tree by the bridleway. Its wild call gives rise to its onomatopoeic name, Yaffle. At this time of the year young Green Woodpeckers are quite obvious and are to be found searching in the grass for anthills where they use their extraordinarily long sticky tongue to pick off the ants. I have encountered them in all the suitable grassy places around Otmoor, such as at Noke's sheep grazed fields  and also in Long Meadow. They can look extraordinarily primitive, almost reptilian, when taken unawares on the ground, as they freeze into immobility, their un-nerving pale eyes staring and their formidable bill pointed skywards.

The juvenile Green Woodpecker's plumage is a duller version of their parents, only showing as a messy, greyer and muted impression of the striking full adult plumage.Their face and underparts are barred while their upperparts are spotted and this will only be lost when they moult into  adult plumage. The young woodpecker this morning seemed a bit disoriented and clung to the thin dead trunk looking about, somewhat confused. It clung on silently, one foot in front of the other for five minutes before bounding off along the hedgeline.

Juvenile Green Woodpecker
Woodpeckers share with cuckoos and kingfishers in possessing what is called zygodactyl feet, in which two toes face forward and two back on each foot. This can be seen on the left foot in the image above. This adaptation is thought to assist in clinging firmly onto trunks and branches of trees. On a more prosaic note an image of an adult Green Woodpecker is used by Bulmer's to promote their Woodpecker Cider, perhaps an echo of the woodpecker's ecological relationship with oak trees and orchards.

Brown Hairstreaks

These are the latest of our five native species of hairstreaks to appear, usually emerging in August although this year they have been early and have been about since mid July.They can be enigmatic in that, sometimes, you can arrive and find one nectaring on a flowerhead, usually bramble or thistle, almost immediately, while at other times you can wait hours for one to descend from its 'master' Ash tree or even fail to see one at all. There is no requirement to get up early to see them as rarely do they become active before around ten am and by four pm they have usually returned to roost in their favourite Ash tree.

I was keen to see one, as so far this year I had met with a distinct lack of success, so after my walk around Otmoor I wandered down the Roman Road, which is a narrow, grassy, short bridleway bordered by high hedges of hawthorn and blackthorn, as well as harbouring a few mature ash and oaks. The blackthorn is important as it is the hairstreak's food plant and on which the females will lay their eggs. 

The Roman Road has become a well known area along which to find Brown Hairstreaks and I found several 'enthusiasts' already staking out the several large ash trees which are the favoured haunt for the hairstreaks. A couple of this tiny butterfly had already been seen in the ash trees but they were high up and not providing the desired viewing, which is when one descends to nectar on the bramble or thistle flowers at head height or lower and they are accessible for photos.

The sun had unfortunately been reduced by now to occasional bursts as cloud slowly moved in but I remained ever the optimist. At least we were sheltered from the strong southwest wind that was blowing through the tops of the trees. After thirty minutes standing under the ash trees and noting a couple of Purple Hairstreaks but no sign of a Brown Hairstreak I had almost given up when I noticed a group of butterfly 'aficionados' looking intently at some brambles towards the other end of the Roman Road. I wandered up to join them and found they were looking at a very worn Brown Hairstreak, footling about on some blackberries. It was in a fairly bad state, being not only very faded but with very ragged, torn wings but nonetheless it was a Brown Hairstreak, my first for this year.

A very faded and worn Brown Hairstreak
We admired it for fifteen or so minutes and then our attention was drawn to another, just a few metres further on. This individual was in much better condition, being pristine and showing its orange- brown underwings in all their glory. Unfortunately it was a little way in from the track and at whatever angle one looked, it was almost impossible to get a shot of its whole body and wings due to bits of vegetation obscuring parts of it. Consequently we stood for twenty or so minutes waiting for it to move, while, frustratingly it seemed perfectly happy to continue to wander over its chosen bramble flowers without ever giving a clear enough view.

I was standing, waiting patiently for it to move when another small brown butterfly fluttered down and settled on a leaf, literally a foot or so in front of me. I looked and then looked again. I could hardly believe my eyes. It was another Brown Hairstreak, again in absolutely perfect condition. It sat briefly with its wings closed and then slowly, hesitantly began to open them to embrace some fortuitous sunshine, until they were spread wide to reveal large orange splashes of colour on its brown upper wings. It was a female. In all the years I have come here to the Roman Road to watch Brown Hairstreaks this was easily the best view I have  ever had of one. No one else had noticed its arrival so I drew their attention to it and everyone took as many images as they wanted before it fluttered away and we lost sight of it in a tangle of vegetation.

Female Brown Hairstreak
So now we returned our attention to the other hairstreak, still feeding on its bramble flowers and which finally, obligingly, flew onto a nearby leaf and gave all of us the perfect angle from which to take its picture and then, as with the other hairstreak, opened its wings to reveal it too was a female. It remained perched here, immobile, for ten or more minutes before sidling head first down the leaf stem and then flying up and away over the brambles and surrounding hawthorns.

An absolutely perfect ending to my morning on Otmoor

Otmoor Update   6th August

I was so enthused by my sightings of the Brown Hairstreaks two days ago I was determined to see if I could repeat the experience and so, today, in the late morning once more made my way to Otmoor. It was sunny and warm and when I got to Otmoor I found the car park already full, apart from, conveniently for me, one space just vacated by a departing car. By chance I met Tim as I parked the car and with whom I had first made an acquaintance when we shared a Purple Emperor experience at Bernwood some weeks ago. Tim had never seen a Brown Hairstreak and did not even know where the Roman Road was  so it was fortuitous that we met in the car park as he could come with me and hopefully I could help him to find a Brown Hairstreak.

We walked down the Roman Road and found a small crowd already looking at a Brown Hairstreak perched in the master ash tree. The views were not quite as good as last time but still more than adequate and from an aesthetic point of view the butterfly looked quite beautiful perched amongst the partially shaded and sunlit stems and leaves of the ash tree.

At first it was hard to see as it was hidden behind a thin twig but eventually it slowly moved around on the twig, more into the open and the sunlight to reveal that gorgeous orange-brown colouring on its underwings. Once you knew where the butterfly was it was quite obvious as the orange triangle of wings stood out amongst the shiny green leaves of the ash, looking for all the world like a dead leaf.

We stood and waited to see what, if anything, it would do, hoping it would fly lower but it was disturbed by a Purple Hairstreak and fluttered to perch on the top of a leaf  at roughly the same height as before and commenced, as the sun warmed it,  to open its wings to reveal two large orange splashes on its upper wings, signifying it was a female. Like the other pair of females from two days ago it was still pristine, with not a mark on it and  even its two tiny tails, one each protruding from its respective lower hind wing, were fully intact. 

Sat up in the tree on its leaf it looked an absolute picture. Because of its location we were looking up at it and when it partially opened its wings, we could see from the underside they were so thin and delicate that  the sun shone through the orange patches, giving the butterfly an almost ethereal presence.

We were constantly hoping it would come down lower to feed on a bramble flower or thistle head but it steadfastly remained aloft and after some time on the leaf returned to the same thin twig it was frequenting before. It was joined by a Purple Hairstreak which sidled up and started showing an unhealthy interest in it, the two of them facing each other and creeping around the twig. The Purple Hairstreak was persistent in its unwanted attentions and eventually the Brown Hairstreak grew tired of being harassed and flew higher up the tree to sit on the tipmost leaf at the end of a twig, before finally ascending up through the leaves of the tree, almost to the top and inevitable invisibility, and it was here we left it after forty or so minutes in its company.

Purple Hairstreak and Brown Hairstreak head to head

We spent another hour and a half in the Roman Road but there was never a sign of another Brown Hairstreak. Southern Hawker dragonflies were patrolling the ride and one finally perched, low down, hanging from the vegetation by its black segmented legs.

Southern Hawker
Further along I found some Roesel's Bush Crickets hopping and hiding amongst the thick juicy tangle of bindweed leaves and grass by the side of the Roman Road.  The cricket is named after August Johann Rosel von Rosenhof, a German entomologist.

Roesel's Bush Cricket-male

Roesel's Bush Cricket-female
I like crickets, their chunky bodies and compact shape with those enormously long feelers are somehow satisfying and appealing. Roesel's Bush Cricket are now common and widespread in Britain and are regular on Otmoor at this time of year although they can take some finding.

1 comment:

  1. Lovely shots of the brown hairstreak Ewan, I saw my very 1st on the 1st at Whitecross when I visited your area I have some images on my site on the HOME page under 'Oxfords Double Whammy' Regards Brian.