Saturday 31st May 2014

The annual bistort pilgrimage

Yesterday, Friday 30th May, provided yet more proof of the immense wildlife value of military training areas. This time the location was Camp Elsenborn, a large tract of heathland, forest and boggy areas in the extreme east of Belgium. Certain parts may be entered when training is not taking place, and luckily this was the case yesterday.

As with the military training areas I frequently visit in northern France, the presence of the Belgian Army here has saved the land from becoming agricultural land, and has therefore allowed the wildlife to thrive, safe from the plough and from agricultural pesticides. In addition to the butterflies I shall shortly describe, I was treated to encounters with a pair of Wrynecks, two pairs of Red-backed Shrikes, two Black Storks, a singing Woodlark, Whinchat and many Wood Warblers, all birds that survive here thanks to the camp, which has been in the possession of the military since it was set up by the Prussians in 1894.

The wild landscape of Camp Elsenborn

An isolated boggy pool in the military camp

The weather was cold and grey initially, but finally a few breaks in the cloud appeared, followed almost immediately by the first butterflies. The first to be spotted was a Grizzled Skipper, Pyrgus malvae, which was basking with its wings wide open to catch the warming rays of the weak sun.

The Grizzled Skipper, almost immobile with the cold

Shortly afterwards, the sun really began to break through, and this brought out perhaps one of my very favourite butterfly species, the diminutive and rare (but here locally abundant) Violet Copper, Lycaena helle. This beautiful species is restricted to damp areas where its larval foodplant, Bistort, Polygonum bistorta, grows. Here the pinkish spikes of bistort flowers may be seen along streams and in boggy areas, and the attendant Violet Coppers provide a beautiful spectacle as they bask on open ground or on flowerheads close by.

The male Violet Copper has a wonderful purplish sheen

Female Violet Coppers lack the purple sheen

A Violet Copper nectaring on its larval foodplant, the bistort

A mating pair of Violet Coppers

The other feature here was the delightful Chequered Skipper, Carterocephalus palaemon, which as I mentioned in my previous post, seems to be enjoying a real boom year in 2014.

A Chequered Skipper with wings fully open to catch the sun

Thus far all the butterflies seen had been tiny, but it was not long before a larger, blackish butterfly appeared, a Woodland Ringlet, Erebia medusa. This species is particularly difficult to photograph, as it always seems to bury itself in long grass as soon as it lands. Luckily I was able to find at least eight individuals this time, and one did perch with its wings open for a few moments before it too obscured itself by burrowing down among the grass stems.

A Woodland Ringlet almost unobscured by grass stems

This is how Woodland Ringlets usually pose!

Later in the afternoon, I found myself in a more sheltered valley a short distance away, and here I was delighted to find the other bistort specialist, the Bog Fritillary, Proclossiana eunomia. I had feared that I might be too early this weekend for this species, but scanning over a patch of bistort with the binoculars revealed at least one fritillary flying, and as I plunged into the boggy vegetation, I was able to find two newly emerged individuals of this wetland specialist butterfly. Within a week or so, Bog Fritillaries will be quite numerous in these bistort-filled valleys, but it was a bonus to find two of them on this occasion.

A newly emerged Bog Fritillary

By the end of the day, my 2014 butterfly list had reached: 48 species.

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Monday 26th May 2014

A case of unintended environmental vandalism!

Following my highly successful visit to the military camp in the northern Champagne region described in my post of 18th May, which provided me with many new species of butterfly for my 2014 list, I returned to the same area this last weekend….only to be almost completely unable to find any butterflies at all. This had nothing whatever to do with the weather, which was admittedly cool, but not cool enough to thwart the butterflies. To my horror, the entire broad strip of rich, varied wildflower-covered grassland between the road and the bank bordering the military training area proper had been mown, leaving only the very shortest plants still with flowers. Literally thousands of in some cases rare species with extremely restricted ranges in this region must have been killed by this operation. That the verges need to be mown is not in dispute, but to do it at the very height of the spring butterfly season is nothing short of environmental vandalism.

In the Netherlands, where mowing of verges is also a national obsession, at least I could contact the Vlinderstichting (Dutch Butterfly Conservation) if I saw such a situation, and they would then try to prevent the mowing happening again in the most sensitive areas, but in northern France no such charity exists to protect butterflies and their habitats, so I have no idea whom to contact.

The splendid verges of the military camp, uncut last year in June

Every square metre of the verges had been mown, leaving little opportunity for butterflies to survive

Luckily, the rest of the grassland of the military area remains untouched, so I can only hope that the butterflies will re-colonise these wonderful verges from over the bank, but that may take some time, and this mowing may become a more regular feature. As it was, on this occasion I saw a total of about seven butterflies, a Black-veined White, Aporia crataegi, a Dingy Skipper, Erynnis tages, a Marsh Fritillary, Euphydryas aurinia, a Glanville Fritillary, Melitaea cinxia, and two Reverdin’s Blues, Plebejus argyrognomon, and one female of a new species for my annual list, the Adonis Blue, Lysandra bellargus.

A lone female Adonis Blue that evaded the mowing

Following this great disappointment, I drove a short distance into the nearby hills, and although the weather had cooled down even further and therefore no butterflies were flying, I was able to marvel at the orchids that this tiny reserve harbours, and in particular the Violet Bird’s Nest Orchid, which seems to be thriving here.

The Violet Bird’s Nest Orchid is a spectacular species

There were several clumps of the Violet Bird’s Nest orchid growing here

Other orchid species I saw in this small area were Fragrant Orchid, Common Twayblade, Early Purple Orchid (already over), Greater Butterfly Orchid, Late Spider Orchid, Lady Orchid and the truly spectacular Lizard Orchid. A small patch of Military Orchids were nearby.

The Fragrant Orchid has rather dainty, petite flowers

The Greater Butterfly Orchid does not really resemble a butterfly

The Late Spider Orchid is not particularly spider-like

The Lizard Orchid’s flowers are quite bizarre

The following day, I headed eastwards into Belgium, and almost immediately I had crossed the border, I found a new species for my 2014 list, a rather tattered female Mazarine Blue, Cyaniris semiargus, which I did not manage to photograph.

Unlike the negative example of human interference in “natural” habitats I had witnessed the previous day, here I was able to enjoy an area that has been cleared especially for butterflies. Although the species that was supposed to benefit in this particular case, the Marsh Fritillary, Euphydryas aurinia, appeared to be absent, nonetheless the distantly related Heath Fritillary, Mellicta athalia, was clearly benefitting greatly from the newly opened up areas. I must have seen at least 20 individuals.

A sign detailing the habitat restoration project for butterflies here

Heath Fritillaries were here in good numbers

Other interesting species present here were Black-veined White, Aporia crataegi, Pearl-bordered and Small Pearl-bordered Fritillaries, Clossiana euphrosyne and C. selene, and more than 20 Chequered Skippers, Carterocephalus palaemon (this charming species seems to be having a boom year). But perhaps my most spectacular find was not a butterfly at all, but rather a mating pair of Poplar Hawk Moths, Laothoe populi, which my eyes were somehow drawn to in the long grass by the track.

A real prize: a mating pair of Poplar Hawk Moths

The Poplar Hawks allowed an extremely close approach

By the end of the weekend, my 2014 list had reached 46 species.

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Sunday 18th May 2014

Spring butterfly catch-up

This weekend has provided a most welcome opportunity for me to clinch some key spring butterfly species, which would almost certainly have eluded me in 2014 had the weather not been as wonderful as it has been, and had I not had the chance to visit my favourite locations in southern Belgium and northern France.

I started off from home in the Netherlands on Friday morning, and by mid-afternoon I was on station in one of my regular forest haunts in the Viroinval region of southern Belgium. Before I had even opened the car door, I noticed several Chequered Skippers, Carterocephalus palaemon, settling close by on the ground. When I did open the door, I was immediately hit by an unpleasant smell – there was a broken, rotting bird’s egg, which appeared to be attracting them, although I did not observe any butterflies actually feeding from it. The Chequered Skippers were so insistent that I had to shoo one out of the car boot!

The Chequered Skipper is one of the most attractive spring butterflies

Setting off along a long, straight section of track, it was not long before I spotted my other target species here, the Pearl-bordered Fritillary, Clossiana euphrosyne. I had written in last weekend’s post that I was slightly concerned that I would miss this species this year altogether as I had already seen the Small Pearl-bordered Fritillary, Clossiana selene, which normally appears just as the Pearl-bordereds are going over. However, they were still out in good numbers here, and I was pleased to add them to my list.

A Pearl-bordered Fritillary nectaring on Bugle

An extraordinary amount of work has been done in recent years for butterflies in the Wallonie region of Belgium, with forest rides being broadened to allow the sun to penetrate the otherwise dark woods and wildflowers to flourish, and some areas of woodland being cleared altogether to open up extra areas of limestone grassland, which has had the added benefit of revealing some extraordinary rock formations that had long been overgrown and invisible.

Having had my fill of these woodland butterflies, I drove the short distance to a contrasting area of open grassland, where my first addition was the Small Blue, Cupido minimus, one of Europe’s tiniest butterflies. Restricted to areas where its larval foodplant, Kidney Vetch, grows, this discreet butterfly is always hard to follow with the eye as it skitters along through the long grass.

The Small Blue is a discreet little butterfly

On the stony, south-facing slopes lower down, I was pleased to find another species I could easily have missed for the year, the Red-underwing Skipper, Spialia sertorius. Superficially similar to the commoner Grizzled Skipper, Pyrgus malvae, this butterfly reaches the northernmost limit of its range here, and is restricted to only the warmest parts of the reserve.

The Red-underwing Skipper is superficially similar to the commoner Grizzled Skipper

Back on the flatter area at the top, my eyes were drawn to a fluttering form paying considerable attention to the flowerheads of Cowslip….a female Duke of Burgundy, Hamearis lucina, yet another potential absentee from my 2014 list.

The female Duke of Burgundy laying her egg under a Cowslip leaf

This is the sole European representative of the Metalmarks, a largely South American family. These are recognised by the fact that the male walks on four legs, while the female uses six. I had ample opportunity to see that this was clearly a female, as she was so busy searching for suitable Cowslip leaves on which to lay her eggs that she allowed for a long observation at point blank range. I was surprised by how long she apparently needed to rest after laying each egg.

Elated with this success, I moved across the valley to one of the newly opened areas, and it was not long before I was admiring a magnificent female Scarce Swallowtail, Iphiclides podalirius, also egg-laying. This splendid butterfly, perhaps one the most spectacular species in Europe, also reaches its northern limit here, and has also benefitted greatly from the clearance of woodland. It requires the presence of its larval foodplant, Sloe, but the traditional hedges or rows of sloe do not appear to be to its liking; it seeks out low, isolated bushes, in this case growing in a deep fissure in the rocky ground, which probably provide a warmer micro-climate for the caterpillars.

The Scarce Swallowtail is one of Europe’s more spectacular butterflies

On Saturday, I made a pilgrimage to the military camps of the northern Champagne region of France, islands of biodiversity in a sea of intensive agriculture. Anyone who naively believes that the military holding on to large swathes of land is wrong should visit this place; the very presence of the army has prevented these marvellous areas from being ploughed up and converted into the vast, rolling fields that otherwise entirely dominate this area, leaving no space whatever for wildflowers and butterflies.

Entirely closed to the public except where a public road traverses the military training ground, my strategy is to stop and search along the wide road verges, without penetrating into the camp proper. Even here I am always nervous, and I have been questioned on several occasions. My cameras could easily be confiscated, and my lame-sounding explanation “Je cherche des papillons” may not always be so readily accepted.

First impressions indicated that there were no butterflies flying at all, but gradually they began to appear, led by the small fritillaries, of which I was to see three species: the Marsh Fritillary, Euphydryas aurinia, the Glanville Fritillary, Melitaea cinxia, and the Knapweed Fritillary, Melitaea phoebe. The latter two of these particularly favour the areas of grassland that have been churned up by the snouts of wild boar; the ditches the animals create dry out, and provide deep shelters in which the butterflies can bask out of the wind.

The Glanville Fritillary can be recognised by the row of black-centred orange patches around the hind-wing

The Knapweed Fritillary lack the black-centred orange patches

A few Berger’s Clouded Yellows, Colias alfacariensis, were flying rapidly between patches of their foodplant, Horseshoe Vetch, and numerous Dingy Skippers, Erynnis tages, were also present. Blues were surprisingly few and far between, although I did find three Reverdin’s Blues, Plebejus argyrognomon, another species that it on the edge of its range here.

Reverdin’s Blue has a restricted range in northern Europe

It was not long before I spotted a smaller, brownish butterfly, which turned out to be a female Silver-studded Blue, Plebejus argus. It is a strange thing, but I only seem to see females of this species here; perhaps the males here have a female-like appearance.

A Glanville Fritillary on the left and a female Silver-studded Blue on the right

Having avoided being questioned by the French military on this occasion, I drove to a delightful area of low hills nearby, and although the butterflies were disappointing, I managed to see no less than eight species of orchid: Military, Fragrant, Lady, Greater Butterfly, Violet Bird’s Nest, Early Spider, Common Twayblade, and Lizard Orchids.

The Military Orchid is so-named for the upright-looking figures that its blooms resemble

The Lady Orchid is a spectacular species

My final interesting butterfly observation of the day concerned an attempted gang rape of an unwilling female Brimstone, Gonepteryx rhamni, by at one point five desperate males. The female raising her abdomen up behind her is apparently a sign of unwillingness to mate (although it might appear the opposite), and this she was clearly doing. Nonetheless, the crazed males were not easily deterred, and they jostled for position with one another in a frenzy of desire; finally, though, they had to give up and left the female to recover from all this unwanted attention.

Sunday was spent in the large area of forest that I visit most frequently in northern France, and I was pleased to find several Pearl-bordered Fritillaries here too, as I had failed to see them last weekend. One Small Pearl-bordered and several Marsh Fritillaries were also present, as were two Map butterflies, Araschnia levana.

I then drove a short distance to a bushy area of calcareous grassland, where as well as adding Early Purple and Green-winged Orchids to yesterday’s haul, I was delighted to find at least another five Duke of Burgundies (Dukes of Burgundy?), Hamearis lucina. I had slightly feared that they were no longer here, but this was a good number.

The Green-winged Orchid does indeed have slightly greenish “wings”

A Duke of Burgundy ready to defend its territory

One Wall, Lasiommata megera, skittered by with its characteristic flight, but the highlight was the discovery of two Sooty Coppers, Lycaena tityrus, including a female that was clearly searching for egg-laying sites. As I had never observed this species here previously, this a good, positive note on which to end this excellent weekend’s butterfly watching.

A female Sooty Copper searches for its food-plant

By the end of the weekend, my 2014 butterfly list for my usual area had reached: 41 species.

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