A blue tailed damselfly wash and brush up

Blue tailed damselflies (Ischnura elegans) have joined in the summer fun. It may be my imagination but they seem the shyest of the local damselflies, diminutive compared to their cousins.  Common red damselflies have an assertive flight, positively bossy in manner . They are on the wing early too and have been quartering their wetland homes for a few weeks now. Azure damselflies are also purposeful, zippy, an effect accentuated by the vivid almost all over blue of the males. The blue tails though tend to be more wary, fluttering into cover if you approach too boldly. The males are a slate grey with the blue spot at the end of their abdomen sometimes seeming to be in flying solo if the rest of the damselfly is obscured amongst the sedges and herbs. The females are even less conspicuous, although if you can sneak up close you’ll often find one flushed with a lilac thorax (the middle part of the body, bearing the wings and legs) or pale chestnut. This little male is giving himself a wipe behind his eyes before setting off on patrol, stretching his left foreleg over his head to wipe any specks from his bulbous eyes.  His blue tail spot is not fully coloured yet, but will become more intense with time. Watch out for blue specks floating through the plants around wetlands; each speck is likely to be a male blue tail, even if the rest of him is hard to see.

Sun, sex and suspicious parents: damselflies get the same hassle

 

Summer’s damselfies are lifting off in glittering droves. The azure damselflies (Coenagrion puella) have coloured up and the air can seem full of bright blue cocktail sticks deftly exploring the grass and rush swards, or perched up sunning themselves. Times are good in the heat. The males particularly are fidgety, landing for a few seconds then flitting up to argue. They seem unable to leave each other alone. Females tend to be cannier keeping out the way, only venturing out into public when ready to mate and provoking a rash of males to chase after them. These two are mating, the male the bluer one, the female a delicate green, hiding away  a bit in the reeds because other males will attempt to barge in, crash landing to knock them apart. Females will mate with several males. This makes life fraught for all concerned. Males endlessly pester. If a male mates with one female then unwisely abandons her another male can come in, mate and physically remove the first males sperm (I am sure you can find out how but be careful what you web search for). As a result it is much more usual for pairs to stay together for a while, the males going in for what is called mate guarding. The female uncurls from this mating wheel whilst the male maintains his hold around the back of her head with special claspers. They can fly off in this tandem, surprisingly fast. The male keeps a firm hold when they land, his legs folded, sticking up over the females head like an ornate hat whilst the female dips her abdomen into the water to lay her eggs. They still get hassled by single males, but at least they don’t have their parents turning up, unlike in the TV series

Schrödinger’s cat, the Large Hadron Collider and Cresswell's mysterious tadpoles

 

 

 

Blakemoor Farm’s new field corner ponds are doing nicely. The freshly hatched tadpoles of a couple of weeks ago (see 3rd April) are now plump and assertive. They are also playing statistical games. In one of the ponds all the tadpoles are squirming together in a dense black swarm. In the next door pond they litter the sediment, scattered with a pleasing eye for complete coverage. In a third pond there are none.  Statistics are not what inspires many people’s interest in  natural history, although I know of mathematicians who have been lured into ecology on the grounds that it is much more challenging. Statistics have their uses though, especially to summarise and test observations. The trouble is when nature plays fast and loose like these tadpoles. In the first pond there are fairly simple quantitative methods that will tell you that tadpoles have a clumped distribution, whilst in the second pond that they are more or less evenly scattered about. The trouble is that the perfectly clear maths makes no sense overall because the tadpoles are doing different things in different ponds, or not turning up at all in the third pond. I doubt that the Large Hadron Collider, turned back on again today to crack even more secrets of fundamental particles, could help unravel the problem of the mathematically inconsistent tadpoles.  Tadpole uncertainty may not have the ring of quantum uncertainty or the fame of Schrödinger’s cat as a conundrum but they are a lovely mystery right on our doors step, just over a wall from the dune road.

 

Northumberland's dragonfly battles: the contenders are hotting up

The male Broad Bodied Chasers have got all dressed up for the summer.  It takes a week or so from when they first emerge as glittering, golden bundles of energy to acquire this fine blue. Slowly the males' abdomens darken then a haze of sky blue, called prunesence, coats their tails. The younger males look much like females except they have slightly narrower abdomens. They keep out of the way of the mature males in their blue war paint, hanging around hedgerows and paths rather than risk conflict with their older kin. This nervousness changes once their blue fighting and mating colours have developed . Then it is time to head to a pond and challenge for a territory. These Chasers fly fast, often low but with erratic zig-zags, back and forth across ponds, even small, garden sites. They do not mind nearly dug out pools and are happy in cities. Every few minutes the territorial males perch on obvious branches and stems, and you can get close (the photo above was taken with an ordinary digital camera, not a telephoto). They are much more concerned about air-borne rivals than sneaky humans.

Adult Broad Bodied Chasers are good colonists and can turn up almost anywhere. They may not have bred from the ponds across which they now patrol and fight. The best evidence for breeding is finding their larvae, called nymphs, or the cast skins left behind as adult emerge. These skins are called exuviae. They are as gnarly and peculiar to look at as the adults are glamorous and racey. Here is one, the exuviae looking like some parchment mould from which the adult has been cast. The wispy white strands are where the cast skin ran inside the length of the breathing tubes, (trachea), that ramified into the body of the larva to carry oxygen. When the adult emerges and pulls itself free of the old skin these are pulled inside out a bit like when you take off a jumper or coats and the sleeve gets pulled inside out. The dragonfly season is hitting its stride. Northumberland remains a poorly recorded county for dragon and damselfies, even areas such as Druridge Bay that attract good numbers of bird watchers and outdoor enthusiasts. Northumberland is a region into which new species have expended from further south, and the east coast of England is the likely first land fall for occasional vagrants from the continent, just as with rare birds.  The western hills and bogs are even less recorded. Well worth watching out, you are very likely to find something new.

The damselflies get ready to party

Like their larger cousins the dragonflies the damselflies are also hatching earlier, by several weeks. Here is a newly emerged damsel that has fluttered to a perch on which to hide. If damselflies had to catch their breath, this is the moment. When they first heave themselves out of the old larval skin, left clinging to a stem of reed or grass around the edge of the pond, the newbie adults are dull coloured and poor flyers. The blues, reds or greens of the mature adult have yet to burgeon and instead the dull, faintly marked brown intermediate is called a teneral. This one had just about made it to a handy branch, then snuck around the other side where it thought I might not see it. At this stage it can be hard to identify the species but this one if likely to be an Azure Damselfy, which are one of the most common. A give away is the dark line that runs diagonally to about half way across the thorax, in the photo just to the bottom right of the thick black bar that runs the length from the wing bases to the rear of the neck. This half-a-line is typical of the Genus  Coenagrion and in Northumberland Coenagrion puella, tha Azure damselfly, is the only likely find. That is a bit of a cheat, I know. It could instead be a remarkable find of a species never before found up here, and I will double check. For now I did not want to scare the little damsel. It feels a bit intrusive, sneaking up to gawp as it gets changed to dance and fight away the days of summer in search of a mate.

A glamoruous dragonfly hints at summer’s warm days.

This exquisite creature is a Broad Bodied Chaser dragonfly, newly hatched and showing itself off  in the mid May sunshine. These are musclely, showy critters spangled gold when they first emerge. When they take to the wing it looks like someone has chucked a fistful of cheap and cheerful chocolates in the air, wrappers glittering. They are also confiding, allowing a close approach, confident in their getaway speed. Like many dragonflies they wiggle and tilt their heads as you sneak up trying to catch a better view of you. This one was loitering in Newcastle today. I am not sure if they have established at Druridge  Bay, but they have been moving north over the last twenty years, like so many of their relatives. Broad Bodied Chasers are often very quick to turn up in new ponds, even sites with very little vegetation. This individual may be a male or female. The females stay this beautiful collage of gold and browns whilst the males develop a powder blue coating over the abdomen as they mature. Newly hatched males have the same colours as females maybe to reduce trouble from their older kin who see off contenders for the same territories in aerial duels.

I found this one today three weeks earlier than I normally spot them, and the first Common Blue damselflies were fluttering up too, also early. Keep your eyes open along the Bay. The coastal wetlands are top spots for dragonflies and damselflies in the north east but under-recorded. I suspect there are many dragonflies  to be found between Cresswell and Amble that we’ve not noticed before and these unusually early arrivals may be a good omen

Build it at Cresswell and they will come

The sheer rush of late spring is now in force along the Bay. The green flush of new grass and herbs are overtopping the scraggy debris from last year. “Build it and they will come, as the film” famously puts it and certainly the tadpoles have arrived. These tidtads area few days old in the new ponds dug in the corner of the field just on the Cresswell village side of Blakemoor Fram, by the track where many a bird watcher parks. The tadpoles have aligned themselves, strangely reminiscent of aquatic musical notes, along the underside of Flote grass (Glyceria fluitans) leaf blades. The tadpoles still huddle together for protection although the new ponds are still fairly uninhabited by more malicious wildlife. So long as the ponds do not dry quickly (and this corner is a fairly safe bet for staying wet) they should do well. New or temporary ponds make a good refuge from fish or many of the larger invertebrate predators that take a while to colonise. The frogs have got in quick. The new ponds are already markedly different to one another. One is filling up with straggling amphibious grasses as it dries out. Others remain nicely flooded and with varying amounts of Celery leaved buttercup (Ranunculus scleratatus) and Flote grass beginning to establish, classic colonists moving out across the bare substrate.

The adjacent oil seed rape has exploded into bloom, smartingly yellow on the eye and with an evocative wallop of mustard perfume if you walk close by. Well worth doing. It is the smell of late spring turning into early summer, a raw blast of scent and colour. Not every-ones’ favourite but very evocative, a modernist ruthlessness to the colour, smell and wall of stems in contrast to the rough half land, half pool of the untidy corner