Friday 30th August 2013

Who says Belgium is boring?

Today was one of my most successful butterfly days of the year, with 23 species seen (as many as I saw during my entire stay in Scotland), and I could easily have found more had I not restricted myself to one location.

With two particular target species in mind, I headed eastwards into Belgium, arriving at around 11 AM at the Fondry des Chiens, an area of chalk downland with some extraordinary rock formations, sculpted by the rain over millennia into bizarre shapes, and formerly the haunt of ne’er-do-wells and brigands. Today the brigands came in the form of two teenaged boys with a ghetto blaster, blaring out “music” at different locations around the rocks, trying to find the best acoustic spot. So much for peaceful nature reserves.

The extraordinary rock formations of the Fondry des Chiens

Luckily, butterflies are not disturbed by noise, and I spotted a Purple Hairstreak, Neozephyrus quercus, fluttering around an oak tree in the car park before I had even left the car. I later went on to find three of these elusive denizens of the canopy, including one which posed quite low down, but I was unable to prepare my camera quickly enough to get its photograph before it flew off.

After only a few seconds of walking on the open grassland, I spotted butterfly species number 74 for the year, the beautiful pearly Chalkhill Blue, Lysandra coridon. This butterfly is common here, and by the end of my visit I must have seen more than 100 individuals. They were extremely active in the bright, warm sunshine, and did not allow a close approach for photography.

A male Chalkhill Blue, showing his beautiful pearly upperside

Other open-country butterflies in evidence here were several Berger’s Clouded Yellows, Colias alfacariensis, the white females laying their eggs on Horseshoe Vetch, Hippocrepis comosa, and several much deeper orange Clouded Yellows, Colias croceus, whose rapid flight made them look like little fireballs skittering over the hillside. Numerous Brimstones, Gonepteryx rhamni, were stocking up on nectar to see them through their long winter hibernation, and a couple of Wood Whites, Leptidea sinapis/reali, were in evidence near the patches of surrounding woodland/scrub.

One of the most numerous butterfly species here today was the Wall, Lasiommata megera, a cheering sight as this species is in decline in many areas. On two occasions, much darker and slightly larger Wall-like butterflies flew past, one finally landing on a rocky outcrop in a deep ravine – these were a much rarer species, the Large Wall, Lasiommata maera. Sadly this one was too distant to photograph, and it did not open its wings. This is the only area in this region where I know this species to occur, and it obviously requires the warm micro-climate created by these unusual rocks – indeed it lives up to its Dutch name of Rotsvlinder, or Rock Butterfly.

A beautiful Large Wall I photographed in the same spot on 29th August 2009

Further walking revealed several Small Heaths, Coenonympha pamphilus, Brown Arguses, Aricia agestis, Common Blues, Polyommatus icarus, and all three common Whites, as well as several Violet Fritillaries, Clossiana dia, including one which posed for long enough to allow me to obtain a decent shot; normally they are so active that photography is virtually impossible.

A Violet Fritillary posing cooperatively – a rare sight!

In a more sheltered section of taller grassland, several patches of flowering Hemp Agrimony, Eupatorium cannabinum, were growing, their blooms proving particularly attractive to insects including a confiding Holly Blue, Celastrina argiolus, as well as a numerous rather Honey Bee-like species of Hoverfly, but they were in grave danger as I observed a single Hornet, Vespa crabro, literally pouncing on them, stinging them and then dismembering them immediately on the flowerheads.

A Holly Blue nectaring on Hemp Agrimony

A little away from the grassland, in a wooded glade, a large tawny butterfly proved to be a late and rather tired-looking Silver-washed Fritillary, Argynnis paphia; in fact, I went on to see perhaps five of this splendid butterfly, so clearly their season is not quite over. I also saw two slightly smaller fritillaries, which could either have been Dark Green, Argynnis aglaja, or High Brown, Argynnis adippe, but I could not be sure which.

A faded Silver-washed Fritillary, with the sun shining through its worn-looking wings

Returning to the grassland, I decided to have one more look for perhaps my most important target species, and it was not long before a browny-orange butterfly flew past me, and luckily landed on a low branch of an Oak tree: a beautiful, apparently pristine female Brown Hairstreak, Thecla betulae. Fumbling with my camera, I attempted a too close approach, and it flew off over the trees and was lost to sight. My usual technique is to snap a record shot with my Panasonic Lumix, which has a 16X zoom and does not require such a close approach, and then once I have obtained a few pictures, to move in for a close-up with my ancient and venerable Nikon Coolpix 4500, which despite only having 4 mega-pixels and a 4X zoom, takes far sharper shots. Here, foolishly I went straight for the Coolpix and approached too close, thereby spooking the Hairstreak into flight.

Slightly annoyed with myself, I waited for a while, but there was no sign of its return, so I wandered slowly along the sunny bank of woodland at the back of the grassland, and my attention was drawn to a fluttering shape that disappeared under a leafy branch. This time I approached more stealthily, and had the Lumix on full zoom at the ready – a wise move, as it was indeed either the same or another perfect female Brown Hairstreak, and this time she posed so confidingly that I was able to use both cameras, and I even had to shake the branch she was on several times to encourage her to move to a more accessible spot!

The beautiful Brown Hairstreak posing on a Beech leaf

The Brown Hairstreak, now on Oak

The Brown Hairstreak, showing the orange patch on the forewing upperside, which only the female possesses

Brown Hairstreaks are never easy to find. They live at low densities in areas with extensive stands of their larval foodplant, the Sloe, Prunus spinosa, but they also spend much time perched on other trees such as Oak, Ash, Beech or Hawthorn. Interestingly, their scientific name betulae suggests an association with Birch, Betula sp, but I have never observed a Brown Hairstreak near a Birch. Assessing their populations is more accurately achieved by searching for their pearly-white eggs, which can easily be found in winter in the V’s formed where young twigs branch off the main stems of the Sloe bushes, than by searching for the elusive adults, which spend much time perched high in the surrounding Oaks and other tall trees.

The Brown Hairstreak, this time taken with the Coolpix

Although Brown Hairstreaks are theoretically on the wing from late July, they seem to be easier to observe later in the season, and they can go on until late September or even into early October. This one looked absolutely fresh, and yet it may have already been out for nearly a month. I wonder whether the emergence of this species is more staggered than that of other species, most of which emerge within a few days of each other. Whatever, the reason, I savoured my encounter with what was undoubtedly one of the absolute highlights of my butterfly year.

As a final bonus, while mowing the lawn later in the afternoon, I disturbed a Clouded Yellow, Colias croceus, which then landed in a small Ash tree, allowing me to approach what is normally another very hard species to obtain close-up photographs of. All in all, one of my best butterfly days of 2013.

A lovely, rich orange Clouded Yellow in the garden

2013 butterfly total as of 29th August: 75 species

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Wednesday 28th August 2013

A trek across the Dutch Sahara!

Today was my first day back in the Netherlands after my sojourn in Scotland, and as soon as I had disembarked from the ferry in Ijmuiden, I returned to precisely the spot in the dunes near Castricum where I had done my last Dutch butterfly-watching back in July before departing, and where I had seen but had not managed to photograph a Queen of Spain Fritillary, Issoria lathonia. Today there was no Queen of Spain to be found, but I did see at least three Meadow Browns, Maniola jurtina (these are now over in Scotland, but here they have more than one generation, it seems), several Small Heaths, Coenonympha pamphilus, a Speckled Wood, Pararge aegeria, several Small Tortoiseshells, Aglais urticae, numerous Small and Green-veined Whites, Pieris rapae and Pieris napi, three Common Blues, Polyommatus icarus, and a fine Brown Argus, Aricia agestis.

The Brown Argus, showing its underside

The upperside of the Brown Argus, with its characteristic orange “lunules” (spots)

I then drove home to Amersfoort, dropped off my luggage, and headed out eastwards on my annual pilgrimage to the Kootwijkerzand, an extraordinary area of shifting sands and inland dunes in the Veluwe, a high (by Dutch standards, at around 100 metres above sea level!) plateau in the centre of the Netherlands. This area is the last bastion of one of the country’s rarest butterflies, the Tree Grayling, Neohipparchia statilinus, of which it is believed that not more than 50 individuals fly each year, and which are now entirely restricted to this one small zone. I have seen them here in most years, and as they are usually over by the first week in September, I need to see them immediately following my return from Scotland – hence the urgency today.

The dry, sandy habitat favoured by the Tree Grayling

Finding the few Tree Graylings is made a little more difficult by the presence of myriads of Graylings, Hipparchia semele, which erupted from every patch of flowering heather (Ling, Calluna vulgaris). Nonetheless, I know from experience not to look for the Tree Graylings near these heather patches (neither are they particularly attracted to trees). The place to look for them is out on the exposed and apparently sterile sandy areas or on the dry sparse grassland and moss, well away from any flowers. The going is rather tough on the loose, uneven ground, and it took me perhaps an hour or more of traipsing across this unfriendly terrain in the full glare of the sun before I finally spotted one Tree Grayling sailing past. It stopped briefly, but was soon away again, disappearing behind a dune and I lost sight of it.

A lone Red Admiral, Vanessa atalanta, powered its way southwards past me on migration, and several Small Heaths, Coenonympha pamphilus, and a couple of Small Coppers, Lycaena phleas, were noted before I finally reached the north-eastern extremity of the sandy area. Here I turned back, this time heading along the southern edge of the open area, and it was not long before I spotted a mating pair of Tree Graylings, which allowed a close approach, followed by another three individuals. It is a sobering thought to consider that one has seen over 10% of the total population of Dutch Tree Graylings within a tiny area. The next nearest populations are in southern France, the Mediterranean area, across southern Poland and into Lithuania. I have a private suspicion that these isolated Dutch individuals might be a different (sub)species, as they have almost entirely uniform grey undersides to the hindwing, whereas other populations have a bold stripe across these wings – all the more reason to hold onto them by maintaining their unique habitat, the open, shifting inland dunes.

The mating pair of Tree Graylings – may their offspring continue the struggle of this highly endangered Dutch population

Following this success, I shifted my focus to the profusely flowering patches of heather along the edge of the sand, and it was not long before I had a brief glimpse of my other target species, the Silver-spotted Skipper, Hesperia comma. These fast-flying little butterflies, which are hard to keep one’s eyes on when they buzz away almost like flies over the broken ground, are also on the wing until the first week of September, and I was anxious to get them on my list as well. I went on to see three individuals, none of which would allow a close approach, darting off with their skipping flight whenever I tried to come near, camera at the ready. I managed to obtain two distant record shots, but no close-ups. Nevertheless, I was delighted to have caught up with this, my 73rd species for the year!

A distant view of a Silver-spotted Skipper nectaring on Ling

A Tree Grayling which landed on my binoculars at the Kootwijkerzand in 2005

A picture I took here last year – the wind had blown the fir-cones into a perfect line

2013 total as of 28th August: 73 species

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Monday 26th August 2013

A butterflying visit south of the border

In spite of poor weather and the lateness in the summer, my butterfly list is still slowly creeping up. This weekend, we ventured southwards, over the border into England, heading for the butterfly mecca of the limestone hills just south of the Lake District, around the picturesque villages of Arnside and Silverdale. This remarkable area hosts several species of butterfly which do not make it any further north, and we had high hopes of boosting up our lists.

However, Friday evening was cloudy and dull, offering no hope of butterflies at all, and Saturday morning revealed that it had rained torrentially all night, and we were forced to resort to birdwatching at the RSPB’s wonderful reedy reserve at Leighton Moss – not too great a hardship.

Following this, we headed a short distance southwards, to the cliff face at Warton Crag, where even though the weather was still dull, I managed to locate three Common Blues, Polyommatus icarus, all roosting on bedstraw and marjoram flowers.

A Common Blue roosting on bedstraw

A Common Blue on marjoram

Most of the afternoon it remained cloudy, although frustratingly we could see a band of sunshine out to sea all along the coast, but the cloud would not move away – butterfly-hunting can be so irritating, especially when one is short of time!

Finally, towards mid-afternoon, a semi-clearance came, and we immediately made for the most renowned butterfly area of all, Arnside Knott. This high hill, with its mixture of woodland, bracken, grassland and scree, is well known among butterfly enthusiasts as one of the few remaining strongholds of the rare High Brown Fritillary, Argynnis adippe, which I had seen here in previous years, but for which we were too late this year.

Classic butterfly country at Arnside, looking across to the Lake District mountains in the distance

Other than the Large Whites, Pieris brassicae, Small Whites, Pieris rapae, and Red Admirals, Vanessa atalanta, all of which we had observed on the buddleia bushes in the village below, our first sighting actually on the hill was a rather washed out individual of a new species for the year, the charmingly-named Gatekeeper, or Hedge Brown, Pyronia tithonus. I would normally have expected to see numerous Gatekeepers in the Netherlands, Belgium and northern France, but due to my early departure for Scotland, where the species does not occur, I had given it up as a missed butterfly for the year. Nonetheless, we went on to see three individuals, all looking tired and faded.

A washed-out female Gatekeeper, with an irritating grass stem crossing the picture as usual!

Having unsuccessfully scoured the screes for Graylings, Hipparchia semele, and the oak trees for Purple Hairstreaks, Neozephyrus quercus, we ventured slightly further downwards into another favourite butterfly clearing, and it was not long before a dark butterfly appeared. A closer look revealed it to be a female Scotch Argus, Erebia aethiops, also a rather tired-looking specimen, but a good one to see as this species only occurs at two sites in England, both on limestone grassland, whereas in Scotland, where it is far more widespread, it is to be found in boggy areas dominated by its larval foodplant, purple moor grass.

A female Scotch Argus basking on bracken

A few Common Blues were also to be seen here, as well as three or four Speckled Woods, Pararge aegeria, and a fly-by Dark Green Fritillary, Argynnis aglaja, a surprisingly late individual of this species, which should normally be nearly over by now. This brought our English lists up to eight species, and there they remained, as by now it was getting late and we needed to set forth on our journey back to Scotland.

Yesterday, Sunday, dawned with cloudless skies and hardly a breath of wind – ideal butterfly conditions. If only we had stayed one more night at Arnside, we could perhaps have added several more species to our English lists!

Still, one should not cry over spilt milk, so we decided to make the most of the ideal conditions by investigating a beautiful peninsula close to the picturesque harbour village of Garlieston. The vegetation was alive with butterflies all along the shore, and our walk began with us chasing a Wall, Lasiommata megera, a long way along the track – each time it settled on a sunny patch, we scared it along in front of us. Perhaps this is one way in which butterflies can involuntarily spread their ranges!?

A male Wall which we constantly disturbed!

Also to be seen on a flowery area just above the beach a were numerous Large and Small Whites, at least five more Walls, and a beautiful, fresh-looking Painted Lady, Vanessa cardui. But it was once we were back in the shady wood that the most interesting sighting of the day occurred: a Speckled Wood, Pararge aegeria. Although we had seen several the day before at Arnside, this one here was much more exciting. Galloway and southern Scotland in general form a surprising gap in the Speckled Wood’s distribution. It is found in northern England, in Scotland north of the Central Belt, and in Northern Ireland, and yet not here, although perhaps a colonisation is now taking place before our very eyes.

The Speckled Wood, a rarity in Galloway

We had seen a few Speckled Woods at this same location two years ago, but despite thorough searches had seen none last year, so we assumed that that first sighting had been only a temporary blip. But here, basking on ivy in a patch of sunlight, was an undoubted Speckled Wood. Indeed, we then went on to see another two individuals, too many to be pure coincidence. Clearly the Speckled Wood is making a concerted attempt to become a regular feature of the Galloway woodlands. And for me it was an unexpected bonus, bringing my Scottish list up to 22 species, a remarkable score when one considers that I was not here for the Spring butterflies, and that I had not expected to see more than 15 during my summer stay here.

The picturesque village of Garlieston

Total 2013 list as of 26th August: 71

Total Scottish list: 22

Total English list: 8

Total UK list: 23