The presenters on Radio 4’s PM programme said that we needed an Awesome Nature Walk to lift our spirits during this renewed Covid Lockdown. Happily, we had already planned to go on one, and here it is: an Awesome Nature Walk at Wraysbury Lakes.
Sketch Map of the walk as it feels when I’m on the path (rather than mere cartographic accuracy, whatever that is)
The walk begins near the road bridge over the Colne Brook at the bottom of the map, which is by a repair garage. I’ve drawn the sketch map to give something of the feeling of the route while I’m walking it, rather than attempting to make an objective map.
The Area’s Natural and Unnatural History
The area is just outside the M25 ring motorway that informally defines London’s boundary; Heathrow Airport is just inside that, so in normal times (hmm) there is a plane overhead every 90 seconds. Down on the ground, there are numerous lakes which all started life as gravel pits. The River Thames laid down great amounts of sand and gravel in its wide flood plain during the Pleistocene, and the various Flood Gravels now form valuable building materials. Extraction round here has finished, but there are active pits a bit further afield. The pits go below the water table so they fill up by themselves. The large Reservoir is a bit different – it has an enormous high earth bank all around it, so the water level is high above the surrounding ground level (maybe there was gravel extraction there too before the Reservoir was built). A railway runs across the area; it can be crossed at a pedestrian level crossing with a pair of stiles and a lot of looking both ways. To the south of the lakes is an attractive area of thorn scrub with Hawthorn, Dog Rose, Spindle, Bramble and suchlike, with quite a few trees, all very good for wildlife. Down by the lake edges and the Colne Brook are many large Willows and Poplars which grow quickly, lean over, fall, and sprout up anew, forming a constantly-changing cycle of growth and regeneration, and providing cover and roosting-sites for warblers and water-birds.
The lakes have variously been repurposed – one is used by the sailing club, though I more often hear the clatter of rigging vibrating against sail-less masts on windy days than people actually sailing. Another is a strictly private fishing lake, protected by fierce signs and fiercer fences which must have cost a fortune to put up. The lake by the start of the walk is open to wildlife and fishing is forbidden; a delightful trio of icons make it clear that running with a large carp under your arm is forbidden, as is spear-fishing (or is that a black line crossing out a standing fisherman diagonally); frying fish on a griddle is not allowed, though nothing is said about making fish stew in a saucepan, interpret the icon how you will.
South of the scrubland is a pleasantly scruffy pony-field with scattered thorn-bushes and rough grass dotted with tufts of Alfalfa. It rises to a low hill which was once a municipal landfill dump. For some years the dump was grassed over and the ponies roamed all over it; then men came and installed deep pipes to sample and carry away the presumably polluted groundwater; finally, a sizeable array of solar panels was installed and fenced off, complete with security cameras, so ponies and walkers had to make a detour around the array.
So — airport, motorway, gravel-pits, railway, landfill, post-industrial leisure activities, it’s pretty much the classic Urban or Peri-Urban nature area.
The Walk
The bridge over the Colne Brook offers a glimpse of calm nature; the water babbles softly among the waterweeds, and two Kingfishers dark on triangular wings just above the surface. One swerves into a U-turn, catching the sun to reveal its brilliant blue-and-turquoise plumage. What a moment to start a walk.
We dive gratefully down the few steps from the pavement to the path: the pavement by the bridge is half-occluded by unclipped bushes, and the traffic whizzes past perilously close to unwary walkers.
In the sudden quiet we peer through the trees to the lake. A gang of twenty Cormorants is on the water, with a group of Mute Swans.
The path is bordered with Willows and coarse herbs; a patch of colourful Comfrey, once used to help knit broken bones, attracts some Common Blue Damselflies. At a gap in the Willows, a Cetti’s Warbler sings its abrupt, loud song. Some Migrant Hawker Dragonflies scoot too and fro beside the water, their transparent wings whirring, their long slender bodies glittering blue.
Little Egrets, Grey Herons, and Cormorants roosting and preening in the Willows beside the lake: not bad for an Urban Nature Walk
We come to a patch of reeds where we can see right across the lake. A Chiffchaff flits between bushes. On the far side is a bank of Willows, several with protruding dead branches. Perched on these are a few Grey Herons, half-a-dozen Cormorants, and most excitingly three Little Egrets — small white herons with black legs and yellow feet: uncommon visitors here. All of these are predators, feeding on fish and small animals like frogs; the Cormorants fish by diving from the surface, while the herons stand by or in the water, looking out for prey.
The track through the thorny scrub is bright with Rose and Hawthorn fruits — “Hips and Haws” in the fine old country phrase, rich with double entendre, glowing in different shades of red. Across a wide patch of Teasels and Burdocks and Thistles, all tall and prickly in their differing ways, more Hawthorn bushes are still in green leaf but bursting with red fruits, so they are red and green at once, which you might have thought impossible, but there it is, spectacular.
We swing through the kissing-gate and into the pony-field. The animals barely glance at us, the rich grass is clearly far more interesting. “Alfalfa” apparently means “King of Herbs” in Arabic; it was supposedly the finest pasture for grazing animals from goats to camels.
The path rounds the Solar Array; I guess it’s good to know that more and more of our energy is renewable, even if an Electric Vehicle, with its large price-tag, doubtful driving range, and complicated charging arrangements if like me and many city-dwellers, you don’t have a front drive to park and charge it on, is still perhaps a bridge too far. It does feel as if, with one more push, there could be charging points everywhere and affordable prices, and suddenly it’ll look not exotic but obvious. Five years, maybe? Who knows, but at least it’s coming.
The Race Team, putting the “GT” into Gunnersbury Triangle … one of the more bizarre bits of rubbish that must have flown over the fence when there was a garage next door (It seems to be the exhaust pipe of a large motorcycle; and Sarah’s jacket is from sailing races round the Isle of Wight)
Flagon and Oil Can … not to mention the hundred beer cans, dozens of energy drink cans, lemonade bottles, bits of insulation, cable, and mirror … it’s really convenient to heave your rubbish over the fence into the nature reserve, ideal place for it …
Auricularia mesenteroides, a relative of Jew’s Ear, a jelly-like fungus with indeed a mesenteric appearance. (The mesentery is the flexible membrane that ties the gut in place, in case you never did Biology dissections when you were at school.) Alick Henrici found quite a few interesting Ascomycetes, a good day for it after recent rain.
Moth Snowstorm, by Michael McCarthy. John Murray, 2016 (paperback), 2015 (hardback)
This is a powerful book, one of the few on nature that can simply be called great. Perhaps Rachel Carson’s 1962 Silent Spring was the last one.
McCarthy states that nature is under deadly threat from humanity. We build roads, dams, sea walls, houses, factories; habitat is destroyed. We drive cars, fly in planes, live in houses made of brick or concrete; oil is burnt, releasing carbon dioxide, causing global warming. The extra heat warms the oceans, making sea level rise. The carbon dioxide makes the oceans acidic, threatening species-rich coral reefs. We buy food containing palm oil: the palm plantations march across the tropics, replacing species-rich rainforest. We eat hamburgers. Cattle grazing spreads across the world, replacing more rainforest; methane from cow stomachs joins the atmosphere, accelerating global warming. Every habitat is under attack. A 6th extinction, to rival or exceed the great extinctions like the Cretaceous-Tertiary which destroyed the dinosaurs, is under way already.
McCarthy tells what this means in his own experience, his own country, England. When he was a boy, Buddleia bushes in the suburbs were covered in butterflies: now they aren’t. When he was young, car headlights and windscreens were covered in insects; any night drive in the country seemed to be through a blizzard of flying insects, the ‘Moth Snowstorm‘ of his title. Now, if he sees one moth, a single one, on a journey, it is worthy of note. Nature has been thinned out, not quite to extinction in most cases, but the great, joyful abundance is gone, in one lifetime. Half the farmland birds are gone. Common sights like a field of lapwings, a street of house sparrows, a tree full of starlings, are no more.
Nature matters, McCarthy writes, not just for worthy reasons of biodiversity conservation, or even for pragmatic ones like pollination of insect-pollinated crops like beans and apples and cherries by bees tame and wild. Probably, he suggests with grim humour, some scientist is even now hatching a crop plant that won’t need pollination: even honeybees may soon be redundant.
No, he argues, we need nature because our species, Homo sapiens, grew up with it for 50,000 generations. We feel well in nature, on a walk by a river, in the hills, in meadows with flowers and butterflies in the sunshine, on a wild coast whether of cliffs or salt marshes, with thousands of wading birds in great clouds, the wind on our faces. In a word, nature brings joy. Without it, life is sad and grey, missing something vital, whatever the distractions offered by online shopping and instant messaging and all the rest.
Pond-dipping in London Wildlife Trust’s Gunnersbury Triangle local nature reserve
Joy, argues McCarthy, is the one thing that can motivate people to fight for nature. Given that it’s threatened, we need a powerful, universal feeling to drive our politics. As the human population rises and pressures mount, as global warming bites on every continent, we will need to fight hard to keep whatever’s left of nature alive. Our survival, the survival of whole ecosystems and millions of species, depends on it. We need, urgently, to teach people to love nature, for which we need reserves, in cities and outside them, where people can experience the joy of nature for themselves; where children (and adults) can walk and run and play and pond-dip and bug-hunt and laugh and see frogs and foxes and butterflies. Then, and only then, can we urge them to fight.
Upper Spey valley in welcome misty drizzle after months of drought. Hay fields that should be knee high in lush green grass are dry and sparse, hardly coming up to the ankles.
With another day of freezing fog, very dangerous on the roads, nature is telling us that, yes, global warming or no, it’s winter. The false acacia, totally leafless, whirs with activity. A big wood pigeon sits impassively, ignoring the small passers-by. Within a few minutes, these include 3 goldfinches, keeping well away from each other in the branches; 2 male blackbirds, similarly, their heads high on the lookout for competitive activity; 4 ring-necked parakeets, never settling for more than a moment, jumping up squawking at the slightest provocation; 2 redwings, handsome with their contrasting eyestripes; 1 fieldfare, markedly bigger, and a handsome bird when seen in crisp winter sunshine rather than today’s murky fog. A few minutes later, a blackcap appeared: still a bird that we think of as a summer visitor, though a few pass through in winter from colder places. Later still, a great tit jumped in and wriggled about; and a little flock of 6 starlings blew in for a few minutes, sadly diminished from the sort of flocks I remember: and even this local flock used to have 7 members.
The effect as birds appear from and vanish into the gloom is rather of one of those popular tales physicists tell to try to make the public feel they understand what nuclear physics is all about: particles and antiparticles are ceaselessly created by the vacuum, and as continuously meet each other and annihilate, returning to their matrix, the apparently endlessly creative fog, which one would otherwise have mistaken for chilly nothingness.
The Woodland Grayling might not sound exciting, and if your first glimpse of one is of a perched butterfly with folded wings, cryptically coloured in mottled browns and greys, it looks unremarkable, if rather large. But should a male fly boldly past you on a hot sunny afternoon, or come right up to you to take a look at what kind of beast you are, you will get quite another impression. The broad bold white band along the trailing edges of the wings contrasts strikingly with the rich, almost glittering, dark chocolate of the front of the wings. In flight, the Woodland Grayling is a strikingly large, beautiful butterfly, recalling the White Admiral or perhaps the Camberwell Beauty (though I know that species only from pictures in books). It flies deceptively fast, mostly at waist height, and is usually not easy to approach, though it perches often enough, selecting a twig that offers a wide view all around. The exception is when a pair are courting and mating, when they necessarily pay less attention to would-be photographers. The image above shows such a couple, half-perching, half-fluttering in a young Mediterranean Pine tree, with (as the saying goes) eyes only for each other. The feeling of a special moment seized me. Suddenly, for the first time in my life, on this particular hot, dry chalk hillside, with Juniper and Dogwood scrub invading the chalk grassland full of bush crickets and marvellously cryptic grasshoppers, I was witnessing the spectacular private courtship of this local and uncommon species. If entomology could be voyeuristic, this was just the moment for it: the passion, the dramatic synchronised display, the Flamenco fire, surrounded me and filled my camera and my memories.
Juniper and Dogwood scrub invading a hot, south-facing Dordogne chalk hillside. Hay bales dot the valley below; arable land gives way to old hilltop hamlets in the distance, backed by Oak-Chestnut forest.
Broad-Bordered Bee Hawk-Moth
Broad-Bordered Bee Hawk-Moth on Buddleia
The Broad-Bordered Bee Hawk-Moth is the kind of insect that everybody notices, if they happen to be by a flowering Buddleia or Lavender bush at the right time. Like the far commoner Hummingbird Hawk-Moth, about the same size but without the Bee Hawk’s bright coloration, this lepidopteran conclusively proves (if proof were needed) that not all moths are dull and nocturnal.
The Bee Hawk loves the bright sunshine of hot summer afternoons. The buzzing drone of bees, hoverflies, and hawk-moths about rich sources of nectar evokes sleepy siesta-time, hammocks and deck-chairs, cool drinks and a good read in the shade. But for the insects this is not a holiday but a crucially busy time, time to gather sugar and pollen for energy, time to mate and to lay eggs.
The Bee Hawk hovers and feeds much like a bumble-bee, and its colours and flight are sufficiently bee-like to make it clear that this is a Batesian mimic of bees, signalling (untruthfully) to insect-eating birds that they will get a mouthful of painful sting if they try anything. But few birds get the chance: the Bee Hawk flies away much faster than any bee, its broad wings providing both speed and agility.
The oddly symmetric rows of holes chewed in Canna Lily leaves by Bee Hawkmoth larvae
The eggs are laid on plants such as the impressively showy Canna Lily. The thumb-sized caterpillar munches a distinctive symmetrical row of holes across the broad, banana-like leaves of the Canna Lily, the holes growing with the larva’s appetite. After moulting several times to progressively larger versions of itself, it pupates and emerges as a beautiful adult. So if you see a Canna Lily leaf that looks as if a Bond villain has machine-gunned it, you know to watch out for a Bee Hawk, and to impress your friends with your knowledge when you casually remark on its presence.
Ichneumon Wasps
Long-tailed Ichneumon wasp
The long-tailed Ichneumon Wasps, of which there are quite a few species, are equipped with one of the most remarkable physical adaptations in the insect world. The female lays her eggs, not on the ground from a simple opening in her abdomen, but down an egg-laying tube, an ovipositor, that is about as long as the rest of her body put together — see the photograph. She is in other ways very much wasp-shaped, though with rather a long flexibly-jointed abdomen, which too is part of her adaptation to her extraordinary way of life. Like most wasps, she is a hunter-killer. But unlike many wasps, she does not bring the prey back to her nest. She sniffs out her prey, the grubs or caterpillar larvae of other insects, while they are deep inside a plant or in rotting wood. She locates them accurately enough by scent or vibration to guide her drill-like ovipositor down through the plant tissues to the unseen larva, flexing her abdomen sharply to push the ovipositor as necessary. When the tip of the ovipositor strikes the larva, she lays an egg in its body, and leaves. Her egg hatches, and her larva feasts on the still-living prey larva from the inside. Eventually her larva pupates, and an adult Ichneumon Wasp emerges from the prey’s emptied corpse. Charles Darwin found this to be an instance of such cruelty that he lost his Christian faith: he could not see how a loving Creator could deliberately form one species with a way of live that so brutally exploited the life of another. We may see, perhaps, something different: an example of the way that natural selection works with whatever materials are to hand, like a simple egg-laying tube and the standard jointed insect abdomen, reshaping them in small steps (there are plenty of shorter-tailed ichneumons), without any kind of foresight, until they are beautifully adapted to carry out radically modified functions.
A short-tailed Ichneumon Wasp
A far shorter-tailed Ichneumon Wasp illustrates how evolution may have proceeded in small steps to create the long-tailed varieties.
Potter Wasps
While we’re on the subject of beautifully adapted wasp structures, let us mention the Potter Wasp’s fabulous arts and crafts skill.
Dark Potter Wasp pots
The elegant nest pot of the Potter Wasp Eumenes pedunculatus
A different Potter Wasp (a large and handsome species) building her mud nest on a wall. Each species builds a nest of a characteristic shape.
Like the Ichneumon Wasps, the Potter Wasp stings prey and lays her eggs on or in them. But unlike them, she carries them off, not to a burrow like many wasps, but to an elegant pot made of mud. She doesn’t seem to mind which colour of mud it is: here, a female Potter Wasp (it’s always a female, as the sting is part of the egg-laying apparatus) has used red, white, buff, and grey mud indifferently, once in two colours for the same pot. She puts one or if need be two or three larvae in each pot, lays an egg on one of them, and seals the pot with a lid. The young Potter Wasp lives on the paralysed prey, pupates, breaks its way out of the pot, and flies off. The mother provides no further parental care once the pot is sealed: she gets straight on with building and provisioning the next pot.
Spider-Hunting Wasps
Pompilid spider-hunting wasp carrying spider under her body up a wall
One family of solitary wasps has specialised in far more dangerous prey than caterpillars. The Pompilidae, the Spider-hunting Wasps, provision their nests exclusively with predators: insect-hunting spiders. This is a duel between two swift, agile warriors, each armed with deadly weapons, each intent on killing the other. But the Spider-hunting Wasp always wins.
Her method is to search vegetation for spiders. When she finds one, she leaps and flies towards it. The spider rears up to bite, but the wasp, with her long legs for rapid running and wings for flight, is quicker and more manoeuvrable, and in a Samurai-like movement that is too quick for the human eye, she stings the spider, paralysing it. She then grabs the limp spider in her jaws and runs swiftly backwards to her burrow. Once there, she lays an egg on it and you know the rest of the story.
Grasshoppers
Cryptic Grasshopper
Away from the worst excesses of modern agriculture, with its marvellously clean fields devoid of ‘weeds’, mammals, birds, and insects (through a combination of good husbandry, thorough screening of seeds to remove weed seeds, and pesticides), the Dordogne remains home to many kinds of insect that were once common all over Europe, but are now scarce in large parts of the continent. On the chalk hillsides, roadsides and many areas of meadow and set-aside, Grasshoppers chirp and jump in the longer grass, seemingly as happy as the blithe take-no-thought-for-the-morrow protagonist in Aesop’s fable of The Ant and the Grasshopper. Seen close up, as in the photograph, a grasshopper is visibly wonderfully well-adapted for its lifestyle. Leaving aside its powerful hind legs for hopping hundreds of times its body length, let us look at its head and thorax. The head carries strong jaws capable of slicing through tough grasses, sensitive antennae warning of approaching predators, and large compound eyes made of many hundreds of tiny single-pixel eyelets called ommatidia. You can see how these are arranged as little hexagons in a detail of the same photograph.
Array of ommatidia visible in grasshopper’s compound eye
But the grasshopper isn’t just good at detecting predators. It is also splendidly adapted for avoiding them. Its first line of defence is its disruptively patterned body, in other words its camouflage. The various browns, buffs, ochres and blacks are not softly smudged to “blend in” with the background. They are the opposite: brightly coloured, sharply patterned, to attract the eye to suppose the bold stripes are anything except grasshopper: bits of leaf, dry twig, stones, shadows, tiny shafts of sunlight. The result is to delay recognition: the grasshopper hides in plain sight, its surface fully visible to predators, but its presence unsuspected.
Should camouflage fail and a predator approach too close, the grasshopper has two more tricks up its sleeve. You know the first one: it suddenly springs into the air, flinging its body high and far. If it has wings, it goes further and faster. As it lands, it often quickly scuttles to one side or under some kind of cover, and freezes. It becomes almost as hard to locate as before, even if the predator was able to see where it landed and to follow close behind. This still-dangerous eventuality is made less likely by trick number two: the grasshopper flashes a brilliant patch of colour – red, yellow, or blue, for instance. This ‘deimatic behaviour’ may often startle the predator – perhaps it has disturbed something dangerous? – for long enough to enable the grasshopper to fly off and disappear in safety. Just a plain greeny-brown insect that chirrups in the grass? Not a bit of it.
Asiatic Hornet
My next insect has a distinctly bad reputation, and not a wholly undeserved one, but it actually spends very little of its life troubling humans. The Asiatic Hornet indeed has a formidable sting: I can vouch for the strongly deterrent effect of being charged by one of these hornets, and stung: my legs were unaccountably in rapid motion before I had consciously registered what was happening when I unfortunately walked up to a small hornets’ nest in a hazel trunk that had fallen across a path, so my instincts were working well that day, too.
Asiatic Hornet stalking prey
The photograph, taken at no great risk to the photographer for the reasons I’ll now explain, shows what Asiatic Hornet workers get up to on a normal working day. The hornet is hovering in a patch of garden mint, whose nectar-rich flowers have attracted a cloud of butterflies, hoverflies, bees and other insects. It is rather uninterested in nectar: it’s after meat, in other words other insects. It is such a powerful predator that it can take on pretty much any flying insect – I can’t vouch for its ability to kill large armoured beetles like the Tanner Beetle which is found in the Dordogne woods, but I wouldn’t be surprised. But first catch your hare, as they say (misquoting Hannah Glasse’s ‘First case your hare’, i.e. skin it before cooking, but I digress). The hornet is a fast flier, but somewhat heavy, like a big truck able to get up a frightening speed on the motorway, but not to steer too well around sharp corners at the same time. Among the mint, the hornet lurks until it spots a possible prey insect to its front. Then it puts on a rapid dash, often ending by bumping into something, whether the other insect or a plant stem. All the dashes I witnessed ended with a butterfly zipping smartly out of the way and escaping with a jinking, zigzagging flight. The hornet invariably reversed, and carried on hovering. When it bumps into a slower insect, it grabs it, and with a quick sting, powerful enough to subdue a small mammal let alone an insect, the game is over. The hornet then carries the prey back to the nest, where she, or her sisters, feed it to their queen’s larvae. In short, Asiatic Hornets are hardworking, co-operative, and generally perfectly peaceful citizens. Unless you happen to be another insect, of course, in which case hornets are ruthless predators, dacoits, thugs, assassins, muggers, footpads, highwaymen, professional killers, people who hang about where likely victims congregate and pick their targets at will: call them whatever you like, it’s all in a day’s work to a hornet.
Cow-Fly
Tabanus bovinus: a giant horsefly, actually associated with cows. Its beak can slice through cowhide (or a deckchair)
The other large Dordogne insect with a fearsome reputation is distinctly less glamorous than the exotic Asiatic Hornet. People often think it’s a loudly buzzing bee or hornet, but it is something very different. It’s a true fly, a dipteran, in the horse-fly family, Tabanidae. But it would be better to call it a Cow-fly, as its Latin name reveals: Tabanus bovinus, the bovine gadfly. Both Shakespeare and the Ancient Greeks record that it can drive cows mad as they try desperately to escape these efficient little predators.
Like all true flies, it has only a single pair of wings, its hind wings having been converted by evolution into small drumstick-shaped organs that whir like little gyroscopes (you can see one if you click on the photograph to enlarge it). These give the fly a continuous stream of data on its accelerations, whether roll, pitch, or yaw, and enable it to manoeuvre rapidly and accurately. The dragonflies do something similar with their large, heavy, but rather loosely attached heads, whose accelerations they sense as they fly, and for the same reason, to enable precise flight control.
The Cow-fly uses its senses and quick flight to zoom up to where cows or other large prey – such as humans – are standing. But it does not rush straight in to dangerous situations. It is cautious, if not (in human terms) downright cowardly.
Its method of attack is to land on a branch or wall near the chosen prey, and to wait, observing the prey’s behaviour. If the prey swishes its tail – or its fly-swat, hat, or badminton racquet – vigorously and near the Cow-fly, the insect often flies off. In particular, if the fly-whisk actually makes contact with the fly (an audible clonk with a hat works well), it promptly adopts the motto ‘He who fights and runs away / lives to fight another day’ and buzzes off as fast as it can. But if the prey stands languidly munching grass, or sits quietly reading its summer novel in its deck chair, the Cow-fly moves in for business. In a short, nearly silent leap, it lands on the prey, stabs its beak through the animal’s hide, and feeds on blood. On the far softer skin of a human, it forms a large swollen red wheal, which itches for days afterwards.
The Cow-fly’s splendid (from its point of view) adaptation to getting blood from its prey make it vulnerable to a simple human defence: sit inside. The fly is attracted into a room where people are moving, but then it is easily caught. Either it perches on a wall or ceiling, where it is readily swatted: or, if the lights are out and a window is bright, it flies to the light and bounces off the glass. It then buzzes about a few times, gives up, and lands on the glass, where it cannot escape the fly-swat – even if you miss the first time, you will get another shot, as it will soon land on the glass again, its instincts driving it towards the light. Such is the science of fly-swatting.
Longhorn Beetles
Male Monochamus sartor, a Cerambycid longhorn beetle
Cerambycid Longhorn Beetle Strangalia maculata on Spiked Star-of-Bethlehem
Saperda punctata, a rare green longhorn beetle with black spots
The Longhorn Beetles of the Cerambycidae family include many large and handsome species, including several of the largest insects found in Europe. They are found in forests, for a good reason. They lay their eggs in dead wood – fallen timber including tree trunks, different beetles preferring different tree species. The soft grublike larvae grow plump, safe (more or less, given what we know of Ichneumon Wasps, not to mention Badgers with strong sharp claws, sensitive noses, and a liking for fat insect larvae) deep inside the rotting wood, often for several years. Eventually, one summer, they reach full size and pupate, and the magnificent adults with their heavy armour, distinctive patterns and the improbably long antennae that give the family its name emerge, to mate, lay eggs and die.
Banded Demoiselle
Male Banded Demoiselle, Calopteryx splendens
Of all the interesting and handsome insects the Dordogne has to offer, one of the most attractive, and most characteristic of its little rivers, is the Banded Demoiselle, Calopteryx splendens. Its Latin name means ‘The Shining Beautiful-Winged’, and that is no exaggeration. This large damselfly is sexually dimorphic – the male is blue, the female a clear green. It is the wings of the male that give the insect the name Banded, and make it so conspicuous to the people who go down to the river to picnic, fish, swim, or canoe.
If you do that, your eye will be caught by the dancing, flickering wings of the male Banded Demoiselles as they patrol their stretch of water, on the lookout for females and for rival males. The dark blue patch on each of their four similar-sized clear wings creates a shimmering effect as the wings beat. When the sunlight strikes a group of such males, their bodies glint metallic, iridescent blue with hints of peacock, and their wings sparkle and flicker together over the cool, shifting water, creating an effect that seems to dazzle and enchant the eye, making their movements hard to follow, the number of wings difficult to count. If you are lucky, you will see a pair of Banded Demoiselles ‘in cop’, a blue and a green insect flying around together with eight wings in harmony, mating and then laying eggs, still clasped together. As a couple, they dart down to one little piece of floating or emergent pondweed after another that may provide a suitable place for their offspring to develop into the next generation of Banded Demoiselles, leaving an egg in each chosen spot.
Stair Hole, Lulworth. Soft Wealden Sands (foreground) overlie crumpled Liassic clays and marls (left) which in turn overlie hard Jurassic rocks of Purbeck and Portland limestone (dark rocks, centre). (Click to enlarge)
Steering Committee (Jan, Ian, Wendy) discussing usage scenarios for the new hut with LWT CEO, Gordon Scorer
Negative Stakeholder: Flood! The view from the committee meeting. The water poured rapidly down the path, and cut an erosion channel beside the end of the hut. And yes, we had remembered to include flood among the scenarios.
After a morning sheltering inside from the pouring rain, it cleared and I drove down to Creag Meagaidh, the enormous national nature reserve that fills a watershed from Loch Laggan up to the named mountain. The sun shone nearly all the time despite billows of cloud to the south. The hills were blue, setting off the shining grey-green of the birches, the russet of the heather – the Ling just coming into bloom now – and the bright yellow-green of the mossy grass.
Trailing Beards of Lichen, mostly Usnea with some Ramalina; the flatter leafy lichens are species of Parmelia
The Downy Birch is a stockier tree than the Silver Birch, tough enough to survive mountain winters, and home to a rich variety of lichens including Usnea beard lichens, bristly Ramalina, dark stringy Alectoria jubata (now renamedBryoria fremontii), and various leafy Parmelia species that yield orange dyes used in Harris Tweed.
Caterpillar of Northern Eggar Moth
Large handsome caterpillars of the Northern Eggar Moth, the Scottish form of the Oak Eggar (Lasiocampa quercus), up to 3 inches (75 mm) long and nothing to do with oak trees, wriggled across the path, their rufous hairs warning off predators. They feed on Heather and Bilberry.
Scotch Argus
In every patch of damp grassland, Scotch Argus butterflies skittered, looking very dark in flight. They are hard to approach as they constantly chase each other off from their territories, but eventually I found one that stayed settled long enough to creep up to. Close up, the upper side is a rich brown, with red patches around the wing edges dotted with black circles that have white centres.
Devilsbit Scabious
A few bumblebees, some of unfamiliar species, visited the Devilsbit Scabious (Scabiosa succisa) briefly. Large Syrphid hoverflies basked on the paths.
Glittering Downy Birches
Further up the valley, a fine group of birches actually glittered in the bright sunlight, the water of the stream shining silver behind them.
Birch Bracket Polypore
A dead birch, stark against the sky, supported stout Birch Bracket polypores, handsomely whitish-grey above, yellow ochre below.
Bog Asphodel Bell Heather Marsh Orchid
In the boggier patches, Bog Asphodel and Marsh Orchid flowered among the Bell Heather.
Rock Bog Heather Birch Mountain Tundra
I turned the corner of the valley to see snow still lying in the deep, north-facing gullies on Creag Meagaidh, and the striking notch of the col that gives access to the mountain ridge.
