2015 British Butterflies – 21: Silver-spotted Skipper at Aston Rowant NNR, Oxon and Purple Hairstreak – 21st-28th July

The last downland butterfly of the season to emerge is the dainty and rather charming Silver-spotted Skipper that is confined to warm southern sites. After Black and Brown Hairstreaks this species attracts the next most visitors to Oxfordshire, being present at several Chilterns escarpment locations. Here it can be fairly numerous through late July and August darting about in the flowery sward or basking on rough chalk scree.

As common is the sight of genuine butterfly enthusiasts searching the noisy hillside above the M40 at Aston Rowant NNR (N). That is where I look for this butterfly first each year, though it also occurs at more sites running south: Linkey Down, Bald, Shirburn and Watlington Hills, and Swyncombe Down. In each of the last two seasons I was the first BC UTB observer to record the species, my 12th July sighting in 2014 being the earliest in recent history.

This year SSS was first seen on 17th, while I found just one of them in the usual spot four days later then three on 23rd. They require warmer conditions than any other British butterfly, not usually being active in temperatures below 20° while even on hot days spending time basking on patches of scree. Today (28th) in equally cool, windy and grey conditions to those previous two visits I finally captured a SSS basking in the open. The hindwing damage so early in the flight season could perhaps be due to the battering inflicted by current weather conditions.

Silver-spotted Skipper

Silver-spotted Skipper

silver spotted skipper_01.1502 aston rowan

Here are some other photographs of high summer insects taken on these visits:

Also on the wing through late July and August is the Purple Hairstreak. This commonest British Hairstreak is easily overlooked because it spends most of its time in the canopy of Oak woods. Like other tree dwelling hairstreaks, getting close to them depends on whether there is a shortage of honey dew in the tree tops. Last year along the visitor trail at Otmoor RSPB reserve, Oxon I came across some PH nectaring on brambles below isolated Oaks. Those individuals allowed a point blank approach and macro lens photography. But more usually these pictures (below) taken this season at the Forestry Commission Bernwood Forest site are how the species is seen.

Purple Hairstreak

Purple Hairstreak

Purple Hairstreak

I have made two recent searches of likely spots on Otmoor without success. Numbers of butterflies at a particular location can vary greatly from one season to the next, though colonies rarely stray far from the tree in which they breed. The archive picture (below left) is what I was looking for. During one of these searches I captured the only local butterfly that had not featured previously in this series, the migrant Painted Lady.

2015 British Butterflies – 20: Grayling and Silver-studded Blue at Yateley Common, Hants – 25th July

The English summer has lost its way again in the last two weeks. I cannot recall a year like 2015 for day after day of grey cloud but little actual rain. Then yesterday (24th) it rained steadily all day, which though boring to sit out refreshed the countryside as was needed. Today was forecast to present a good insect watching window at last, so in company with Ewan I headed back to the area of heaths south-east of Reading and north of the M3 first visited in midweek.

Our first stop was Yateley Common (SU825595) to seek out the two characteristic butterflies of English lowland heaths. The site, comprising 476 acres of heathland, woods and ponds is managed as a country park by Hampshire County Council. So much for the fair weather forecast! Once again it was a morning of waiting for brief bursts of sunshine through endless and oppressive grey cloud. For an hour and a half we explored likely looking habitat without finding anything. I am used to seeing Grayling in stony patches of heath or posing for the camera on dead wood or fence posts, but that’s when the sun is shining. Eventually Ewan put one up as we walked then used his bushman’s skills to relocate it several times.

Grayling

Grayling

Here was the answer: the Grayling must all have been sheltering down in the bell heather and ferns. The advantage of the cool and breezy conditions, as is usual was that this individual allowed a point blank approach. The macro lens image (above) brings out the subtle beauty of this master of camouflage. We could have trampled habitat trying to flush more of them but with acceptable pictures gained the job was done and we try not to do the first option anyway.

Grayling, one of the later butterflies of the season to emerge, is locally common on southern lowland heaths or coastal cliffs and dunes. More than any other British species it is confined to dry, sun-baked places where the soil is poor and vegetation sparse. I have seen large numbers on the Dorset Heaths and usually stumble across them during August dragon flying visits to the New Forest. When the forewing is tucked down so the eye spots are hidden, the grey and brown marbling of the underwings makes these butterflies very difficult to pick out. But once they are startled the forewing pops up again to expose the bright eye spot.

silver-studded blue_01.1501 yateley common

Silver-studded Blue (male)

Grayling sites on southern heaths are often shared with the diminutive Silver-studded Blue. This declining species is now absent from four-fifths of its former range but from mid-June through into August can be present in thousands where it does occur. I had already seen them this year at a plentiful site, nearby Silchester Common (SU 620620) but didn’t get good enough pictures on that day. Today’s cooler conditions were better for photography, as the nicely-posed male (above) nectaring on Bell Heather demonstrates. This was one of just two SSB that we found at Yateley Common today.

The silver studs of the species’ name are in the centre of the black dots around the hind-wing margins, but do not stand out in today’s picture. The sequence below presents the underwing detail of three other blues for comparison.

2014 SSB (female) showing silver studs on the black spots

2014 SSB (female) showing silver studs

Brilliant Emerald dragonflies at Warren Heath, Hants – 22nd & 25th July

I have always found Brilliant Emerald to be one of the most difficult dragonflies to observe. Why so? Because they fly fast and low around pond edges, seldom settle and keep beneath overhanging vegetation as much as possible. In 2013 at Esher Common, Surrey I watched one doing just that over and over again, always approaching from away to my left and vanishing to the right. I also saw them at Thursley Common’s Moat Pond that year but not since until now.

2013 Brilliant Emerald

2013 Brilliant Emerald at Esher Common

This national rarity is locally common within a limited area of south-eastern England, south of the Thames and London where it favours acidic soils and coniferous woods. This week I read up on a well-known site at Warren Heath (SU774596), just inside north Hampshire and visited first on 22nd to get to know the species better. The exact spot wasn’t easy to locate but a call to Jason Coppock (aka Badger) who had been here before put me straight. From just opposite the Eversley Materials Recycling Facility at SU784586 a track leads down through Forestry Commission woodland to two large ponds in a valley bottom. And that is where the metallica, as BE is known from its Latin name live.

Today's secluded location

Today’s secluded location

Water Lilies - I love 'em

Water Lilies – I love ’em

It was possible to walk all around the edges of the larger pond, and despite only intermittent bursts of sunlight two Brilliant Emerald were active at the eastern end. Cue a text to Badger thanking him for his excellent directions. I then retraced my steps along the pond’s northern edge finding two more BE, one of which was patrolling up and down close to the western bank and moving relatively slowly in the low light conditions. So I decided to retrieve my chair and lunch and stake out that spot with the camera all afternoon if necessary or until it rained. After too many chalk hillsides of late and suffering more than a bit with asthma this week I fancied a restful sit down.

Irritatingly it was the second (rainy) possibility that prevailed. Fairly soon after I returned dark shower cloud moved in from the west, ending dragon flying for the day. I encountered about five metallica in all here at this first attempt but realised that getting a suitable photograph to post on this blog could be a challenge. In the meantime I out-sourced the picture below.

Brilliant Emerald rights of owner reserved

Brilliant Emerald (male)
© rights of owner reserved

I also captured this immature male Keeled Skimmer (a first) in this forest today

An immature male Keeled Skimmer in the forest

I re-visited this afternoon (25th) with Ewan who had not seen Brilliant Emerald before. We spent a couple of hours watching them in the same spots as on Wednesday doing the same as the Esher Common one had done two years ago, which of course is just what metallica do. According to Brooks and Lewington, males rarely and females never take prey at water, feeding and mating both taking place in the surrounding tree cover. I did manage another blurry flight shot today (below) and having got to know this superb site could gladly spend more time here in quest of the precious perched photo.

2015 Brilliant Emerald

2015 Brilliant Emerald

Ewan checking his shots

Ewan taking the weight off his feet

New Forest Odonata – 1: Latchmore Brook – 18th July

High summer is also a time for enjoyable day trips to the Hampshire playground of the New Forest.  The valley mires and streams of this huge tract of lowland heath support around 28 different dragonfly and damselfly species, 70 per cent of the resident British population. The distance is a convenient 85 miles and a visit here has yet to disappoint.

For my first excursion of 2015 I chose a new site, Latchmore Brook because one of only two regular English damselflies that I had yet to see is found here. Scarce Blue-tailed Damselfy occurs only at scattered sites across southern England because it has very specific habitat requirements that are met by certain valley mires. A parking area at Ogdens (SU182124) lies conveniently next to the brook that can be explored upstream from this point. My research had indicated that Golden-ringed Dragonfly are found along the stream itself, while Keeled Skimmer and SBTD should be looked for in peat bogs on rising ground just to the north.

Latchmore Brook

Latchmore Brook

Arriving here at 10:30 am I first checked out an adjacent boggy area but found no odonata at all. Then I walked upstream for about a mile until the bed began to run dry. A few Keeled Skimmer were around and not having seen males either at Cothill Fen or Decoy Heath this year I was pleased to photograph one here. These bog dwellers are smaller and slimmer looking than the other British skimmer, Black-tailed with a tendency to up-curve their hind end when perched. Another New Forest regular, Small Red Damselfly showed itself here and there, while Beautiful Demoiselle were present in numbers everywhere.

About two-thirds of the way along this watercourse I began to notice large dragonflies patrolling low over its surface, first one way then back the other over and again. These were the magnificent Golden-ringed Dragonfly, banded yellow and black with green eyes that meet in a point on top of the head. This species is common and widely distributed in heath and moorland areas. All the insects I observed today were males that didn’t settle much. But there were spots here with dead wood perches that I thought could yield interesting photographs if staked out on a future visit.

Golden-ringed Dragonfly

Golden-ringed Dragonfly

A short distance back from my turning point I reconnoitred a more promising looking bog on the stream’s northern side. Here there were better numbers of Keeled Skimmer suggesting this might also be a location for the lifer, SBTD. I returned to the same spot after a lunch break and this (below) is a Scarce Blue-tailed Damselfy, one of two found. The diagnostic is that the blue tail band covers part of segment 8 and all of 9, and has a convex upper edge. In males of the larger Blue-tailed Damselfy segment 8 is all blue and 9 black. The insects I recorded today had a noticeably more delicate appearance than the much commoner latter species.

Scarce Blue-tailed Damselfly

Scarce Blue-tailed Damselfly

I had to get muddy to capture this poor quality image. Adjusting position and camera settings to secure a better one could have involved sinking in to who knows what depth. Wellies would be a definite advantage for any repeat attempt. This was still a very pleasing result, meaning the last regular English damselfly I need to record is Scarce Emerald.

2015 British Butterflies – 19: Small Copper and Chalkhill Blue at Chiltern escarpment sites – 17th July

With high summer woodland species all now recorded my focus has switched back to the chalk grasslands of the Chilterns escarpment and south Oxon downs. In late July and August several downland butterflies already experienced in late spring produce new broods, and possibly my favourite amongst these is the Small Copper. Widely distributed but nowhere very numerous, this bright and lively little butterfly can turn up in almost any rough grassy place.

The most reliable local site I know for the species is Swyncombe Down near the village of Ewelme, Oxon. From a parking spot at SU666914 a path leads uphill through woods to an open access area. I have rarely walked through the gate at the woodland edge onto the hilltop without seeing Small Copper in a small hollow to the immediate right. Today I sat on an anthill at that location for just a few minutes and true to form one appeared.

Small Copper

Small Copper

Two or three Small Copper is a typical day list count at any chalk downland site, and today was no exception. Much field Scabious is in bloom at the moment and this is always an attractive perch on which to capture butterflies such as the Marbled White (below). And Gatekeeper are a common site everywhere currently.

The second half of July is also when chalk grasslands become blessed with the pastel beauty of flying Chalkhill Blue. This last blue butterfly of the season inhabits unimproved chalk and limestone downs across southern England. But my first site visited today is not notable for it and so I relocated to the banker that is Aston Rowant NNR (N). There I found several males around the hillside above the M40, but the blustery conditions made photography almost impossible most of the time. But with persistence and experimentation I gained results that compare with my best from previous seasons.

Chalkhill Blue

Chalkhill Blue

chalkhill blue_01.1504 aston rowan

This is what I meant in my last post by a communion with insects that is difficult to experience in a crowd. Many more Chalkhill Blue will be flying at this and other Chilterns escarpment and south Oxon downs locations very soon. Before leaving I trod the area of hillside where I find my first Silver-spotted Skipper in any season, but didn’t see that other site speciality today.

2015 British Butterflies – 18: Purple Emperor and White Admiral at Bernwood Forest sites – 11 & 15th July

Not having seen Purple Emperor at the first attempt, I returned a day later to a different site in the Bernwood Forest complex for another try. Butterfly Conservation’s Purple Emperor field meetings were taking place in Oakley, Shabbington and York Woods on 11 & 12th. I have attended these in the past but now prefer butterfly watching alone or with just one or two companions. That’s because whereas birding is best done in a group I have come to enjoy a communion with insects that is impossible when numbers of people are standing around talking or jostling for camera space.

Hence I headed for Finemere Wood, Bucks (SP722217) hoping for a less crowded option. The area most usually referred to as Bernwood Forest is the Forestry Commission property visited a day earlier (10th), but the ancient hunting forest of Bernwood once covered much more land either side of the Oxon and Bucks border. Now a mosaic of woodland and hay meadows remains stretching north-eastwards from the villages Beckley and Stanton St John, just outside Oxford into countryside beyond the A41 between Bicester and Aylesbury. The Berks, Bucks and Oxon Wildlife Trust (BBOWT) manages five nature reserves within this complex: Finemere, Rushbeds and Whitecross Green Woods; Bernwood Meadows and Asham Meads. These are variously important for the “big three” woodland butterflies of July and the scarcer Hairstreaks.

DSC_0002

click to enlarge

Arriving at Finemere Wood at 10:30am I joined a small number of thankfully knowledgeable observers who were watching two Purple Emperor (pictured below) in tree tops about a third of the way along this site’s main ride. But these did not descend to the ground as they can be relied upon to do at the Forestry Commission location. Being accessed along a farm track from the nearest road where there is limited parking, Finemere is not troubled by dog walkers or joggers and when the sun shines its only open ride becomes a corridor of frenetic butterfly activity. While we were watching the Emperors, two White-letter Hairstreak were active in the same tree tops, my second 2015 sighting of that species.

Tree top Emperor

Tree top Emperor

There were White Admiral gliding about at intervals but these are not generally inclined to perch for long openly, and hence it can take some time to secure good photographs. I then relocated to Whitecross Green Wood (SP600150) to try my luck there. This second location has a lot of brambly spots to attract White Admiral and Silver-washed Fritillary, but the grassy record shot below was the best I could manage this time. Once flying the condition of White Admirals can deteriorate quickly as the lower image demonstrates, so if they are not captured when newly emerged acceptable pictures can be difficult to come by.

White Admiral

White Admiral

white admiral_01.1502 whitecross green wood

My photography has definitely suffered at times from compiling this series, since there is now always a pressure to secure pictures of a certain standard for each species I feature. Last summer I was wiling days away with less photographic purpose and hence results were often more creative. It was good to get the tree top record since this is how Purple Emperor are often seen, but the required image is of this majestic butterfly at ground level and in five years I have yet to secure a truly satisfying photograph of White Admiral.

A three day rain break ensued then as the weather brightened again this morning (15th) I headed back to Oakley Wood. Arriving at 11:15am as the sun was breaking weakly through blanket cloud cover, I hoped that if like me the Emperors had been stuck at home for three days they might now be more inclined to come down from the trees and pose on the ground. I walked the main track again as far as Shabbington Wood, seeing one Purple Emperor flying amongst Oaks and my year’s first Purple Hairstreak, another speciality species at this site.

Returning to the car park to retrieve my sandwiches at around midday I hung around to see what would happen. Sure enough a male Purple Emperor glided down from on high and settled on a car. This was in just the same spot where I had parked on the 10th (see here) and later been told that a female had settled nearby. Whatever it is that they gather from the gritty surface of the main track, today’s butterfly was probing for with its proboscis on the car tyres. It then set about striking interesting poses on another nearby car.

purple emperror_01.1506 oakley wood

Purple Emperor (male)

These pictures (above) are a bit different from what I’ve taken before. Well everyone gets the ground level shots don’t they, but here’s a couple more anyway (below). I went to alert two enthusiasts from Bristol whom I had passed on the track, and being still nearby they hurried back to the car park. It was one of them’s first Emperor and both were delighted with my find.

Purple Emperor (male)

2015 Purple Emperor (male)

purple emperror_01.1504 oakley wood

The pressure now being off I next followed the main paths around York Wood to see what else was about. On this walk one of many Silver-washed Fritillary indulged me with an almost premium quality photo shoot, and I also captured two more local butterflies (pictured below) that had yet to fill their supporting roles in this series.

On reaching the gate from York Wood into Bernwood Meadows (SP609112) I did a circuit of this lovely wild flower meadow. There was a profusion everywhere of one of my favourites, Knapweed that made for still more photo opportunities. The sound of grasshoppers was all around and countless dozens would zip in every direction to escape my footfall. Eventually I just had to get down on all fours with my macro lens to record these. I believe they are Meadow Grasshopper –  confirmation please anyone?

Wild flowers in Bernwood Meadows

Wild flowers in Bernwood Meadows

It is possible to enjoy many hours browsing these various sites in the Bernwood Forest complex, that are managed for the greater public good by BBOWT, WREN and the Forestry Commission. I spent around four hours in these woods today and in that time what was a half-baked blog post has become a celebration of high summer wildlife. We are so lucky in Oxford to have all this habitat and its nationally important butterfly populations on our doorstep.

2015 British Butterflies – 17: Essex Skipper in Burgess Field, Oxford – 10th July

It is now high summer and countless millions of butterflies fill the countryside. Four familiar groups are absolutely everywhere. The common brown species of any grassy place or woodland are being joined on the wing by second brood whites and new brood Vanessids produced by the early season hibernators. And darting about amongst all of these are the diminutive, moth-like brown Skippers: Large, Small and Essex.

I know of two reliable Oxon locations for the enigmatic Essex Skipper: Hagbourne railway embankment (SU622894) and Burgess Field nature park in North Oxford (SU497087). Having been alerted by Adam to their emergence at the second one I went to check it out on Friday afternoon. The first brown Skipper I came across in this landfill regeneration site was indeed an Essex and thereafter the long grass and many wildflowers here sported hundreds of them.

Essex Skipper

Essex Skipper

essex skipper_01.1508 burgess field

Though a relatively common species in south-eastern England, Essex is very similar to Small Skipper and hence easily overlooked in the field by experienced and less savvy observers alike. That is unless one wishes to get down on all fours and examine the antennae of every brown skipper encountered.

So here is the Rn’S identification guide to brown Skippers. Most people new to butterflying know that Essex Skipper has inky black tips to the antennae. But Large Skipper have black undersides to their antennae and so are easily confused with Essex depending on the angle from which they are viewed. The key difference is that Large Skipper antennae are hooked at the ends, as the central picture below shows. Small Skipper antennae are golden brown on the top sides and so easier to distinguish.

I had this lesson a few seasons ago from Butterfly Conservation’s former Upper Thames Branch and now national chair Dr Jim Asher. He said the surest way to separate Essex Skipper is to view them head on, as the outside pictures demonstrate. Turned off? Well it’s no worse to me than expert birders banging on about tertiaries, scapulars and greater ear coverts.

In this series I have concentrated on scarcer butterfly species that require particular sites or habitats to be visited. The rest I am classing as “local” butterflies, meaning those that may commonly be seen in town gardens. Here are some more of the locals that I have managed to photograph in the last two days.

It is pleasing to see that following their population dip of the not too distant past Small Tortoiseshell are enjoying a bumper season. Dapper, chocolate brown Ringlet are everywhere in huge numbers at this time of year. Equally attractive in an understated way is the newest high summer brown to emerge, the homely little Gatekeeper. Second brood Small and Green-veined White are both more boldly marked than those seen in springtime. There is no such thing as a mundane butterfly: all are fascinating, intricate and a joy to behold.