Observing oft-recorded British butterflies in new places has been one theme of this most unusual spring of 2020, but on its final day my going back to where it all began for one very special species proved to be even more satisfying. Overnight I had learned that Black Hairstreak were now flying in a particular place to the north of Oxford. So I contacted Ewan who had already checked our own recent location of choice twice this season where none had yet emerged, and we met at the second site just before 9:30am.

When I joined Butterfly Conservation in 2010 and participated in various field trips, today’s location was an acknowledged hot spot for a butterfly that is one of Great Britain’s most threatened and hence sought after in equal measure. The group leader explained how an issue had arisen there with egg collection and that if participants were to return in the autumn we might likely come across a degree of trimming of the Blackthorn food plant hedges.

Black Hairstreak

This particular colony indeed declined over the ensuing years, during which the centre of attention for Black Hairstreak and its attendant, social media-inspired circus moved first to the M40 Compensation Area of Bernwood Forest, then Whitecross Green Wood in Oxfordshire. Most recently another population, close to a long-standing stronghold that had been put off limits to genuine butterfly enthusiasts by HS2 construction works, came under the same visitor pressure with habitat being roundly trashed once again. But no matter where else I went for this particular record, I made a point of still checking today’s site, mostly finding no more than a few individuals and in some years none at all.

Black Hairstreak

All this harassment of an endangered species and habitat pressurisation progressed with the apparent blessing of conservation charities, as they persisted with the folly of prioritising hands in new members’ pockets over servicing their core interest groups and support, as all now seem to do. So perhaps no wildlife species symbolises that ongoing misplacement of loyalties better than the Black Hairstreak butterfly.

Black Hairstreak

Today we found a cluster of up to a dozen Black Hairstreak at the same spot I had first visited on a BC field outing 10 years previously. These were mostly keeping near the tops of the Blackthorn hedges since there were no flowering wild plants such as Bramble or Privet to bring them lower and so offer the kind of point blank communion we had enjoyed at other sites in recent years. But every so often an individual would indeed pose agreeably enough for acceptable pictures to be obtained.

Black Hairstreak

I do not really need more images of any previously recorded British butterfly in this current season, having an extensive collection already. But being unable like everyone else at present to travel abroad and widen my butterfly experience I must be content with repeat exercises such as this. My policy is to get in and out early where Black Hairstreak is concerned, before the circus arrives back in town.

Having recorded the species for 2020 and gained the studies presented in this post, some of which do seem a little evolved from those of other years, I now feel less need to visit other sites. That things have turned full circle for Black Hairstreak in a former stronghold where it appears to be thriving once more is especially gladdening. And so I intend to leave this most beleaguered of our butterflies in peace to see out it’s brief June flight season free from my own further attentions.

My present national butterfly agenda includes one site visit for each of the early season Fritillaries, so today I returned to the ancient Oak woodland of Wyre Forest at Bewdley that I first visited in this same week 12 months ago (see here). Meeting Ewan at the usual start time of 10am in that site’s Dry Mill Lane car park (SO771762), our quest was Small Pearl-bordered Fritillary of which this NNR hosts a healthy population.

Small Pearl-bordered Fritillary

We first walked westward along the hard-surfaced access route of a former railway line. This was being very well used by family groups, dog walkers and cyclists, and every day in the countryside seems like a Sunday at the moment in the still surreal post lock-down climate. In track-side areas that must be managed for them we soon began to notice Pearl-bordered Fritillary, amongst which some individuals (pictured below) were still quite fresh. But how aware of this local treasure the human footfall all around us may have been I cannot say.

Pearl-bordered Fritillary

Pearl-bordered Fritillary

Those butterflies are now nearing the end of their flight season, but that of Small PBF is just beginning. So we turned off this busy thoroughfare and took a path steeply down into the valley of Dowles Brook that adjoins the northern edge of the reserve. In the rather idyllic setting of stream-side meadows at our trek’s end we encountered much richer brown and faster flying Fritillaries that at once stood out from the still present Pearls, and that was what we had come here to find.

Small Pearl-bordered Fritillary

Small Pearl-bordered Fritillary

The easiest way to separate Small Pearl-bordered Fritillary through binoculars on first encountering them is to pick out the black chevrons surrounding both underside wing edge pearls, a prominent black dot near the centre of the hind-wing, and markings along the top-side edge of the fore-wing that appear to spell the letters 730. The two sequences above illustrate those diagnostics quite clearly.

The two butterflies are also quite different on jizz once the observer has their eye in. On this sunny morning the presumably male Small Pearls we found here were all very hyperactive, patrolling endlessly in search of mates. On settling they would most usually keep tumbling around their flower heads of choice which made gaining acceptable images of them quite difficult to achieve. But I persevered and there were quite a few more butterflies to choose from here today than during my previous 2019 visits.

Small Pearl-bordered Fritillary

A year ago I did rather better for top-side than underside studies, but today that situation was reversed. The above collage presents my better results. We remained at this place for around an hour and for much of that time had it to ourselves. I would fear for the lush habitat here if this tranquil spot ever acquired the popularity for SPBF of Bentley Wood in Hants, hence my vagueness as to the precise location. My better top side studies are presented below.

Small Pearl-bordered Fritillary

After moving on in the early afternoon we birded the woods on the valley sides, encountering two Pied Flycatcher and finding a Great Spotted Woodpecker nest. Common Redstart and Wood Warbler also breed on this reserve but we did not find any today. Lastly we walked back along the main access track, and some Small Pearls were now also active amongst the Pearls in the managed areas viewed in the morning. The under-wing images herein featuring Horseshoe Vetch were all captured in that second location.

I dealt with SPBF in detail in the two posts published in this journal in 2019, so this account of a follow up visit is a briefer, picture-based treatment. Much of the specific wildlife agenda I went into this present remarkable year with has had to be abandoned, but re-experiencing these two little treasures of any British spring was always going to be part of the plan.

I had not visited this classic Wood White site for five years since the previous, brief post in this journal as part of my 2015 British butterflies series (see here). Indeed I have not recorded the species nationally during that interval, so given my current re-working of the British list, when Ewan asked me to accompany him there today I opted to join him.

The courting dance of springtime Wood White today

My own access point to Bucknell Wood outside the village of Silverstone has been along a track at its southern end (SP 65882 44750), from where I have usually found this butterfly immediately. But on arriving there at around 10am my colleague was in the main Forestry Commission car park a little to the north, and neither of us knew of the alternative locations. So through the course of this exercise we both became aware of a second option, which was perhaps apt at the present time with many times the usual numbers of people visiting the countryside and parking areas being under pressure.

At first I set out along my usual past route, but as it was overcast and windy it was plain I would not find any butterflies yet. So I went up to the other access point and belatedly our paths crossed. The conditions remained distinctly butterfly unfriendly for the next hour, and then we had to shelter as best we could from a minor soaking. But as that weather front drifted eastward across the wood, extensive clear blue sky followed behind it. Such a scenario seemed perfect for accomplishing our mission as butterflies would emerge again as the late morning warmed up, and so things transpired.

Though the site was now sunlit strong wind was still afflicting the main rides, but along a more grassy and sheltered track I eventually came across a first roosting Wood White on an exposed perch. This was presumably a female since a second butterfly arrived on the scene and proceeded to dance around the first (pictured above, right). But the latter appeared to be getting the old cold shoulder and so presumably “he” flew off. Before too much longer we were encountering several of these ghostly waifs (pictured above) and two maturing Broad-bodied Chaser dragonflies (below) across the same area.

Broad-bodied Chaser (imm)

Broad-bodied Chaser (imm)

The Wood White displays a noticeably dainty jizz compared to Small or Green-veined Whites, having one of the slowest and most delicate flights of any British butterfly. The smallest of those three, they indeed flap their oval wings so under-statedly as they glide about that the distinctive faint patterning is readily visible, and always rest with wings closed. Unlike other whites these live in self-contained colonies of a few dozen and largely remain faithful to their breeding area in English woodlands.

Adults in southern sites typically begin to emerge in late April, peaking in May and lasting into June before dwindling through that month. The average life-span is eight days, though some individuals can last for up to three weeks. There is usually then a second brood in which males display smaller, darker wing tips. Numbers can then be as high again after a warm spring such as the present one, flying from mid-July to late August.

Males spend their time patrolling up to a metre above the ground in their search for mates, checking out any white object they come across. If that turns out to be a newly emerged female they begin the distinctive head-to-head courtship dance captured in this post’s lead image. Our first sighting today must have been less fresh as she appeared to reject the suitor concerned. Females fly only half as much as males and when observed are usually nectaring on plants such as Bugle, Ragged Robin or Birds-foot Trefoil. Males may nectar less on flowers and supplement their diet by mud-puddling for mineral salts if the conditions are right.

Wood White

Wood White was one of the fastest declining native butterflies over the last 30 years of the 20th century, and in 2007 became a priority species in the UK National Biodiversity Action Plan. Mounting concern over its plight led to the development of a recovery project led by Butterfly Conservation. By 2010 only 50 extant sites were identified, of which 13 were thought to have already lost their colonies.

Bucknell Wood is one of a complex of six forest sites in Northamptonshire and north Bucks that hold 20% of the species’ national total. The others are Hazelborough Forest, Whitefield Wood, Sywell and Hardwick Woods, and part of Yardley Chase. Five of those are managed by the Forestry Commission which has worked with BC staff and volunteers to create the sunny rides and clearings that Wood White requires to survive.

After leaving here we paid a brief visit to nearby Hazelborough Forest (SP659431) where in the area we accessed the difference in habitat to that required by Wood White was quite apparent. The next heavy rain belt was also approaching and so we did not linger. But I returned here two days later and indeed found more butterflies in suitable habitat along the main ride and a side track from it. The second brood of the enigmatic Wood White is one I have yet to experience in Great Britain, so a further visit to this area seems quite likely.

The reserve of Strawberry Banks is one I have wanted to experience for some years now, so doing so today gave me an evolved way of recording Marsh Fritillary for the 2020 season. An “unimproved” limestone grassland in the Cotswold AONB, it is privately owned and managed in a traditional way, until recently by the Gloucestershire Wildlife Trust. The most well-known butterfly here each year was my quest for this visit. Famously in May 2011 there was an explosion of 15,000 at the site, though in most years numbers are far more modest.

Marsh Fritillary

The reserve (see here) is accessed from a minor road between Oakridge Lynch and Chalford in the highly picturesque Frome Valley to the east of Stroud, Glos. From there (SO 91164 02938) rights of way lead uphill through the ancient Cotswold Beech woodlands of Three Groves Wood on the right and Oldhills Wood on the left. The SSSI itself comprises two steep and wildflower rich pastures on the eastern side of the minor valley of a Frome tributary that flows between those two woodlands.

Once I arrived on site at around 10am it wasn’t long before a first Marsh Fritillary crossed my path, before doing what this species invariably does by posing nicely on a raised stem. All the butterflies I observed today were along the lowest edges of both meadows, and often displayed a preference for nectaring on Buttercups. But the main food plant is Devil’s-bit Scabious. Over the years I have noted some size variation between different populations observed in Great Britain and continental Europe, and today was struck by the relative smallness of this particular cluster.

Marsh Fritillary

Though once widespread in the British Isles the Marsh Fritillary declined severely through the 20th century. Having acquired threatened status the species has been the subject of much conservation effort over the past two decades and more recently has enjoyed something of a revival. This Gloucestershire breeding colony is a long established one but populations in general are highly volatile and long term survival will depend upon the maintenance of suitable low-intensity grazed habitats.

There are three main habitat types: damp grasslands dominated by tussock forming grasses, ancient calcareous grasslands usually on west or south-facing slopes in England, and shorter coastal grasslands in other parts of the British Isles. Temporary colonies can also occur either in larger woodland clearings or other grasslands. Smaller isolated clusters are easily impacted by sudden changes to habitat.

Marsh Fritillary

Marsh Fritillary

Having become extinct here in Oxfordshire during the 1990s, small numbers of MF have in the last two years been recorded on the South Oxon Downs and at Cholsey Marsh in the Thames Valley, though whether this is due to releases remains unclear. The species has also returned to its last known BC UTB location of Seven Barrows on the Berkshire Downs in the current flight season. And a project is now underway to restore Marsh Fritillary to the damp grassland fields of RSPB Otmoor just to the north-east of Oxford (see here).

I feel pleased to have got around to visiting one of the most constant MF populations in southern England in this scenic and uplifting location of Stroud’s “Golden Valley” (see here). Recording scarcer butterflies in new locations is always satisfying as the ongoing pattern of this most unusual of years continues to confirm.

For new visitors to this blog who might have been directed via a specific species search, the different posts presented herein on British Butterflies are regularly referred to. The most consulted items to date are:

Glanville Fritillary @ Hutchinson’s Bank, Surrey – 1066 views

Marsh Fritillary et al @ Cotley Hill, Wilts – 621 views

Large Heath @ Whixall Moss, Shropshire – 408 views

Wood White @ Bucknell Wood, Northants – 254 views

Marsh Fritillary et al @ Battlesbury Hill, Wilts – 228 views

Duke of Burgundy @ Noar Hill, Hants – 225 views

Large Blue @ Daneway Banks, Glos – 222 views

Black Hairstreak @ Whitecross Green Wood, Oxon – 214 views

Heath Fritillary @ East Blean Wood, Kent – 193 views

Pearl-bordered Fritillary @ Bentley Wood, Hants – 186 views

Pearl-bordered Fritillary @ Rewell Wood, Sussex – 178 views

Purple Emperor et al @ Bernwood Forest, Bucks – 168 views

Duke of Burgundy at Noar and Butser Hills – 132 views

Adonis Blue @ Aston Rowant NNR, Oxon – 127 views

The present exceptional circumstances have ruled out any butterflying abroad this spring, so I have found myself working through the British list once again. And that has proved to be more motivating than I could have imagined pre-Covid 19. Indeed prior to today I had managed to record almost everything that could be expected in a more normal season. The exceptions were Duke of Burgundy and Pearl-bordered Fritillary, that do not occur here in Oxfordshire.

Pearl-bordered Fritillary

So having left the first weekend since lock-down was eased in the British countryside to the general public, whilst myself opting to keep a lower profile, I now hit the road on a bijou day trip to Hampshire. Of the five PBF sites described herein in 2019, the one I enjoyed most was the “East Inclosures” of the New Forest national park, since it was the quietest. This area is accessed from the Standing Hat car park (SU314036) just outside Brockenhurst. My arrival there at around 10am this morning was timed to coincide with these delightful butterflies warming up with the day, before they become too hyperactive to record pictorially.

As soon as I walked into the forest here a first Pearl-bordered Fritillary crossed my path, then along the initial stretch of track out to the inclosures I counted four more. Soon after heading off that hard track towards the hot spot of a year ago (see here), I came upon a cluster of 10 all nectaring on Bugle and the first part of my dual mission for this day was soon accomplished.

Pearl-bordered Fritillary

Places I walked where Bugle was in flower were always the most productive in terms of observing Pearls today. That is one of a number of low-growing, forest clearing plants such as Violet, Primrose and Wild Hyacinth these butterflies depend upon in the ephemeral habitat they require of coppiced woodland where the undergrowth has been cut down for two or three years. When not nectaring males spend their time energetically flitting and gliding up to a metre above ground level in an endless search for newly emerged females. On finding one they will hover around the potential mate until either being accepted or rejected, and this was behaviour I witnessed several times today.

I was fortunate to have found this concentration so early in my visit, as the most productive spot of last year was far less so when I reached it this time. I then explored more rides coming across Pearls mostly in ones or twos in different places. The seven silver pearl markings that edge the underside hind-wings, and so account for this rather special butterfly’s name are visible in this sequence (below).

Pearl-bordered Fritillary

When I arrived here the forest seemed gloriously empty after the weekend, and for much of my three hours on site I had things largely to myself, save for the intermittent company of a Hants BC transect walker. But by 1.00 pm the location had inevitably filled up with general public. I moved on to a Duke of Burgundy site at Farley Mount near Winchester, but in contrast to a year ago found neither those or Pearls this time. So the former remains a butterfly I may not record for this 2020 British season.

Oxon spring butterflies, 2020

Over the preceding four days since the government lifted restrictions on internal travel I managed to add several spring speciality Oxfordshire butterflies for this year to the commoner species observed in my local countryside over the seven weeks of lock-down. At the weekend everyone I heard from or spoke to who had gone anywhere with a car park used words such as bedlam or pandemonium, as the British public poured en masse into the countryside. In an attempt to keep reasonably remote I chose to walk the South Oxon Downs above Aston Upthorpe, a classic butterfly area.

Green Hairstreak

At Lowbury Hill (SU539825) I gained personal first site records of Green Hairstreak and Dingy Skipper, while Small Copper and plentiful Small Heath were also active. By late morning I was competing for space with motocross riders, and at one point was accosted by the loud occupants of an off road vehicle who just had to disturb me. Those activities are ongoing issues in the locality and the tracks leading to the Ridgeway area were badly rutted during the wet months of January and February this year.

Small Copper

Small Heath

Walking back to my own car through the open access land of Juniper Valley I found more Dingy and Grizzled Skipper, both of which are site specialities. Small Heath and Common Blue were each flying in numbers. A nearby motocross track is closed at present so people must be taking their bikes up onto the sensitive wildlife habitat of the high Downs. Vans and multi-occupied cars passed in the opposite direction once I had left the relative peace of the SSSI.

Dingy Skipper

Grizzled Skipper

On 14th I visited another classic Oxon butterfly site Watlington Hill NT (SU702932) on the Chilterns escarpment, to seek out its speciality Blues. Common Blue and Brown Argus were both duly encountered, the latter mostly around some enclosures that have been created to protect Horseshoe Vetch from grazing rabbits. That is the food plant of Adonis Blue and I was delighted to secure a personal first site record of that iconic spring butterfly there.

Adonis Blue

Adonis Blue

Lastly, the second sequence of Orange Tip pictures (below) was recorded on a local footpath during a walk from home since my recent post on that butterfly (see here). During a somewhat surreal interval one encounter and picture opportunity such as this would often make the day’s outing seem worthwhile, which of course every local walk was.

Orange Tip

The seven weeks of lock-down seem like no time at all to look back on, more like a hole in my memory, and filling each day successfully was motivating in itself. But anything I did prior to this unprecedented experience now seems a very long time ago.