No vultures at Druridge Bay, but a trip to Martian Spain finds some familiar plants.

Pete, Scott and I have had the great good fortune of a trip to Huesca, in northern Spain, for the 6^th European Pond Conference Network meeting. Huesca retains its romano-medieval feel, as if the heat has kept it from expanding beyond the old city walls into the deserts to the south or Pyrenees foothills to the north. Take the desert road south and you come to the county of Monegros, which looks ideal as a film set for Star war’s Tatooine, but instead is known for its spaghetti westerns. The roadside services even affect a wild-west feel with wood balustrades and canopied terraces from which to keep an eye of strangers riding into town. There are at least 140 saline wetlands, called “salades”, pock marking the terrain, largely the result of solution of the limestone and gypsum topography, with the wind also blowing out the hollows. The aquifers are saline too, the hydrology and topography creating a remarkable scatter of salt wetlands deep inland, many of them part of a Natura 2000 designation. They have characteristic vegetation, salt loving xerohalophytes (dry and salt loving), including Atriplex species higher on the edges around the dissolved out drepessions, then distinct zones down to Salicornia patula as the final outpost before the salt crust. The Atriplex are the shrubs in the photo foreground above, the Salicornia the bright green clumps before the open expanse of the salades floor. If you walk down below the line of bluffs around the salades the further horizons cannot be seen and it is easy to this could be Mars with a little bit of gentle terra forming. The fine sediment crusts of the hollows are loaded with the eggs of specialist crustacean such as fairy shrimps, waiting for the rains, and vivid red darter dragonflies perch like sundials on the crackling vegetation. Superficially all very different from the verdant greens of north-east England’s coastline, with its sea frets and northern winds. However Atriplex and Salicornia are familiar species along our coast. Different species, yes, but the same zonation with Salicornia the outer pioneer on salt marshes at Holy Island and Alnmouth, whilst Atriplex species are all along the coast and in the fields at Druridge. However, in Northumberland, no vultures drifting casually overhead though, keeping half an eye on the unwary salades tourists, in we became mired in the cracking salt crust.

The creeping up on red darter dragonflies time of year

 

Red Common Darter dragonflies, Sympetrum striolatum,  may not have the glamour of their bigger brethren such as piratical Emperor Dragonfly or gaudy Southern Hawkers but there is an everyday charm and confiding jauntiness to them that conjures up August (...with an ominous hint of approaching autumn too). They are fond of basking on wooden fences and tables in the sunshine and they soon circle back to their perches if you disturb them. Creep up carefully and you can get very close. Often they waggle their heads, sometimes holding an inquisitive sideways look at you as they try to work out what you are. Their huge eyes, made up of lots of separate single facets called ommaditia, are very good for detecting movement as the shadow you cast crosses from each facet to the next. If they are not in the mood for being crept up on they will depart but they seem to appreciate the warm days of high summer as much as we do and mostly can’t be bothered. Their larvae are rather squat, sprawling critters, again lacking the submarine menace of the larger species. Instead they clamber amongst the debris and submerged plants in ponds.  There are several very similar species of red darters, including migratory rarities such as the Red-Veined Darter, but this far north most of them are the Common red. this one has the typical large yellow splashes on the side of the thorax which are a good ID tip. Black Darters turn up along the Bay sometimes too: they are small and fidgety compared to their red cousins. Darter Dragonflies will last long into the autumn if the days stay warm, but right now are busy enjoying the sunshine, whipping in tight, dog-fighting circles as males vie for supremacy or hovering briefly on the look-out for a mate. Autumn can wait.

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"The small gilded fly doth lecher in my sight" (King Lear, nature lover)

Nature is famously good for us, with talk of “green gyms” (marketing speke for a walk in the countryside) and mental health.  The verdant green of a spring time woodland or flower strewn verge are a delight. I am less sure about the darkened woods of late summer as the leaves strip out all light or the wilder moors: Wuthering Heights, The Hound of the Baskervilles and Lorna Doon are not set high on the moors by accident. Nonetheless Druridge Bay has that overwhelming calm of sea and sky that King Lear could have done with instead of contemplating flies out in the storm. I have always assumed the “small gilded fly” he observed were Long-legged Flies, Dolichopodidae, perky, iridescent inhabitants of damp vegetation and exposed mud. They do a lot of letchering in sight (green bottles do not, so I’m ruling them out). The sun has brought out the more conspicuous Dolichopodiae in skipping, fizzing mobs. Most are very tricky to identify but one is not, Poecilobothrus nobilitatus, on account of the white wing tips of the males. These frantic suitors whirr and fan their wings to females, then hop and skip back and forth over the object of their amorous attention. However since they all tend to crowd together in the drying puddles and rims of the ponds the mob is a constant agitation of distracted flirting and collisions. As each fly shifts and twitches new neighbours jump into view so within seconds they seem to have lost sight of their intended.  They are also easily distracted trying to yank midge larvae out of the mud which they chew up with macerating mouth parts.  If you approach to abruptly the whole mess of flies scatters but lie down to watch and they will soon return to their choice patch of mud for another round of dancing.  They are flies of high summer’s hot days as the ponds dry down to squirming mud and a delight to watch.

The burnet moths cyber noir day out

The July warmth has unleashed a very special day along the dunes around the Druridge Bay Country Park; the burnet moths have hatched. They are not rare nor unfamiliar, but well worth the time to creep up and admire. The newly emerged are shimmering black winged, whilst their bodies are the deepest sable fur. Vivid red spots blotch their wings, five or six spots per forewing depending on the species. Antennae stand proud, a filigree segmented hook of which the finest blacksmith would be proud. They seem slightly out of place on the dunes, dressed for Frank Millar's Sin City. Seen against the yellow of Birds Foot Trefoil or gaudy purple-pink of the Bloody Cranesbill, the burnet moths add to a remarkably colourful dune-scape. Maybe the Burnets are more fin de siècle Gustav Klimt that contemporary cyber noir. The males whirr, slightly clumsily, low through the marram stems or cluster on thistles. They can detect a female in her cocoon even before she emerges and the males wait around to mate even as she hauls herself out. Here are a pair with the females white cocoon as their foot hold. They shimmer in the sun. The high summer butterflies are also out in force. Common Blues fizz  past, the more tentative Small Heaths flitter away from out under your feet and Ringlets bob low amongst the stems as if on the end of invisible strings. Walk the dune path south of Druridge Bay Country Park and you will find these beautiful insects in abundance. The burnets do not last long, their extraordinary looks maybe burn out too soon, befitting their vanity, which deserves your attention.

The Hauxley time machine pond comparison website

The experimental ponds at Hauxley were dug in the autumn of 1994, to monitor the development of the animal communities from the very origins of the habitats. I had imagined this might go on for a few years but not twenty, but the value of the ponds as a study site increases with every passing year. The photo shows one of the original ponds at the front and, just behind, one of the new pools dug out by postgraduate Scott to explore the links between productivity, water chemistry and carbon accumulation in the sediments. In 1994 the old pond looked just as bare and abrupt as its new neighbour, the exposed clay base glistening in the June sunshine, stamped with heron footprints and jackdaw beak stabs. The old pond is now substantially infilled with debris and this is overlain with a sward of moss. Sticking up through are the stems of curl dock, Rumex crispus, their leaf edges conspicuously waved as if the growing leaves had expanded to some precise oscillation. These docks are common place but do not establish in properly submerged habitats. Here they are evidence of the increasing terrestrialisation of the old ponds. The new ponds have rapidly acquired the same pioneer animals that have now largely vanished from the old sites. In particular swarms of waterfleas, Daphnia obtusa, have appeared. The raw, new ponds seem to hold as many species as their twenty year old neighbours. It looks like the new ponds will follow the same trajectory of colonisations and extinctions as the older ponds.

The pond field is looking very beautiful. This year the greens are especially verdant, and the flowers radiate red, yellow and pink against this perfect backcloth. The clouds of pink are ragged robin, Lychnis flos-cuculi, their flowers seeming to hang in the air as if the slightest breeze can keep their confetti shape aloft.

The giant fly attack time of year

Summer now has the wetlands and dunes in its thrall. The warm, wet spring seems to have nurtured the richest greens and every flower is all the more intense against a backcloth of verdant meadow or hedge. At Hauxley yellow buttercups, Barbie doll pink ragged robin and purple spikes of orchids rocketing out of the fields compete to be the most garish. By mid June in some years the land already looks parched, the greens half hearted, but not this year. It is also an in-between time, with many birds having got their nestlings away and the occasional flourish of song suggesting a second brood might be on their minds. At Cresswell Lagoon young little gulls and sandwich terns are already hanging around waiting for something exciting to happen, or, at very least a fish to be brought back by parents who now look smaller than their indolent brood. For me high summer only begins when the meadow brown butterflies appear. Other insects are skipping, hopping, pinging and whirring from every footstep. Get down into the grasses and herbs and the sheer effervescence of life is shocking. as are flies as big as the one above, homing in on me. Nervous readers rest assured, it is not huge, high in the sky coming in from behind the tree, but somewhat smaller and probably disturbed as I crept up on a damselfly, whose turquoise body you can see out of focus bottom right. The marauder turned out to be an Empid (or Dance) fly, which often come with a conspicuous, rigid proboscis on which to skewer smaller brethren and suck them dry. They have perky, upright stance and are often furry too; if it was not for the vicious looking mouthparts they might pass as cute. During this same foray I saw an empid knock down a much larger cranefly and try to find purchase to spear its quarry, although its would be victim managed to buzz free and clamber up a stalk to re-launch itself. Judging by those raised legs and direct approach I got off lightly.

The chamber of earthly delights and a question of scale

 

 

Pete, Dave and Philip are unveiling the latest piece of field work kit. A fine example of the different scales at which people work: Pete seems to be taking a remote sensing view point, Dave bit more hands on, Philip going for the fine detail. The item they are revealing should allow us to work at the scale of whole ponds at Hauxley, the new arrival being a perspex chamber manufactured to fit over individual experimental ponds. This will allow Pete to monitor the gas exchanges from a whole pond, in addition to the more fine grained analyses with smaller floating chambers that we can position over small sections of distinct vegetation types. Initial data show that the individual ponds vary markedly, some ponds exhaling CO₂ and methane, others acting as sinks for those same gases at the very same time. The chamber looked surprisingly large when it arrived, (it looked surprisingly large when Pete tried to get it in his car at the factory). It is designed to extend either side of the ponds and wedge down into the surrounding vegetation to create a strong seal. Eventually the lure of bubble wrap got the better of us.

 

Dave, who is no mean craftsman himself is inspecting the workmanship. The chamber is a hefty and stout piece. The next step is to try this out in the field. We will put the chamber over a pond, and connect it up to the portable gas analyser which samples the air inside the chamber and gives real time measures of the changing concentrations. One unexpected outcome of this approach is the very concrete feel for the ecosystem's processes that you get from watching the numbers tick up on a display screen. Suddenly those invisible gases seem very real, the squidgy ground beneath our feet very lively, as if we are standing on some giant creature, submerged in the swamp.