High Fashion and Green Metal in an Essex Summer: The Lestidae Damselflies

 As it is (ed: Not long past) Christmas, and I have already written of a decidedly Christmassy species, I thought, in the dark of St Stephen’s Night, to revisit the insects with which I spent a privileged summer, through the coastal marshes of Essex. The Lestidae damselflies, or Emerald Damselflies, come in a range of shades from key lime pie green, to metallic fir tree tinsel green, some bearing a dusty blue pruinescence. They are desperately fashionable too, subject of many treatises, management plans and UK Wildlife Podcasts, in part because of their undoubted beauty, more subtle than that of the splendid Calopteryx spp - perhaps more of them later- and less easily spotted than the big Aeshnids I wrote about before. Essex is their spiritual home- and arguably one of the epicentres of their remarkable colonisation of these islands. All four breeding species are found in the county, and I had the privilege of meeting them all over the summer of 2022.

Scarce Emerald Damselfly nomming a Blue Tailed Damselfly (Ishnura elegans)

Willow Emerald Damselfy, RSPB Bowers' Marsh, Essex. 

My first encounter with these splendid creatures was a couple of years ago at RSPB Rainham Marshes, where I met a gorgeous, deep bronze green insect hanging serenely on some wetland tree that may or may not have been the one from which it took its common name. This slim and delicate creature was a Willow Emerald (Chalcolestes viridis) a stunning creature which immediately caught my eye, especially as it was October, when all but the hardiest Common Darters and Migrant Hawkers had reached the end of their season. The Willow Emerald is unique among British odonata as it does not lay its eggs in water, but instead, in neat incisions made in woody vegetation overhanging water with a modified ovipositor. I have witnessed them laying eggs like this while still in tandem, the male gripping the female with his anal claspers, protecting, or jealously guarding her. From these eggs the tiny prolarvae emerge in spring, and drop into the water below to continue their life cycle, much more typically. Any which fail to find water do not make it, but conversely, being to an extent free of the need for water during late summer oviposition offers an advantage in a drying climate.  This species was first recorded breeding in the UK in something like 2009, in Suffolk. On a September walk by the Thames at Tilbury in 2022, with my good friend Chris, we found hundreds of these beautiful, bronze green insects, hanging out on Brambles tens of metres from fresh water. It is a species which has undergone a meteoric rise. Look for an all-green Damselfly, sometimes shimmering bronze in the sunshine as the light catches its iridescence, with clear wings (mind those flashy Calopteryx!) white pterostigmas (the dots in the ‘outboard’ corners of the wings), hanging out on marginal woody vegetation near still or slow-moving water.

Willow Emerald, Tilbury, September 2022

A few years later, while walking among the ditches at an EWT nature reserve way off the beaten track yet not too far from Basildon. Hanging on a branch, apparently relatively freshly emerged, was a beautiful male Scarce Emerald (Lestes dryas). Contrary to its English name, this species seemed very numerous on the sites where it lived. A hulking brute of a damselfly, size being a key if not universally reliable way of separating it from the smaller Emerald Damselfly (Lestes sponsa), and another species identified as having a distinct upward population trend, it likes Sea Clubrush choked ditches, sometimes to the consternation of site managers irked by its insistence on enjoying exactly the habitats wading birds do not, and often co-occurs on the coastal grazing marshes also favoured by Small-Red Eyed Damselflies and Ruddy Darter Damselflies. Like all Odonata it is an active predator, adult and nymph, largely taking small flies,  but not averse to dining on its distant relatives. At RSPB Old Hall, what I initially took to be a mating pair of Blue-Tailed Damselflies, turned out on closer inspection to be a Scarce Emerald feasting on the corpse of a Blue-Tailed Damselfly. In addition to an impressive display of predation, though I had no way of telling whether the Emerald had caught its prey on the wing or simply made a fortuitously (for the Emerald) timed landing, it represented a good chance to compare the blue bits of the two species. The steel blue pruinescence, a dusting of scales which fades with age, contrasted strongly with the almost luminescent looking blue tail-light of the commoner species.  Scan through the big crowds of Blue Tailed Damselflies for this big beast, and use your close-focus bins or a good photo to identify it by the pruinescence covering the whole of the first two segments of the abdomen, and the big, bent-paddle claspers at the back end to separate from male Lestes sponsa. A slightly different pattern of green and pale cream on the thorax separates the females of these species.  Look for them in June and July, I saw few of them after the big heatwave of 2022, for reasons unknown, perhaps it baked off the adults or desiccated any late developing nymphs.

Scarce Emerald (female) Essex 2022

Scarce Emerald (Male) Essex 2022

Historically, the commonest of the Lestidae in the British Isles, and still the one you’re most likely to encounter outside of South Eastern England, is Lestes sponsa, the Emerald Damselfly, you may hear it called the Common Emerald Damselfly.   This species has undergone something of a decline of late, like many of our odonata, as documented in the State of Britain’s Dragonflies report. It is hard to separate from L. dryas, I recommend a good book with the illustrations of Richard Lewington in it and a good pair of low-magnifying small binoculars for close focus, though any particularly small Lestes-with-blue-bits is likely to be one. Sadly I encountered just a few of this species during my summer transects.

Emerald Damselfly, Essex, 2022

The fourth species is the newest, and perhaps the slowest colonising, the beautiful and distinctive looking Southern Emerald Damselfly (Lestes barbarus). This is a gorgeous, key lime pie of an insect, with its dark green metallic upper surfaces contrasting with the pale, green-tinged yellow of its undersides, boasting a unique and instantly recognisable (yes, really) bicolour pterostigma, half milk white, half blackish brown. It has distinct ‘antehumeral stripes,’ look for markings like braces on its thorax. Its stronghold is on Canvey Island, of all places, I am advised a particular ditch is a good place to look, but I found it on the site near Basildon, where it was a new record. More delicate looking than the other three, it was first recorded in Britain in 2002, in Norfolk, and it’s been gradually colonising low-lying Essex since being discovered at Wat Tyler Country Park by Neil Phillips in July 2010, with other early records coming from Gunners Park, Shoeburyness in 2012. It is a more committed climate change rebel, and habitat specialist, than even the Willow Emerald, relying on ditches drying up in late summer for oviposition. I could scarce believe my eyes when I found one near Basildon on an EWT reserve. These species are moving so fast and unpredictably with their quiet invasion that they are one group in which the observations of keen eyed amateur naturalists and local surveyors can make real changes to known distribution maps.

Southern Emerald Damselfly, EWT site, Essex. 

So think of them on these winter days, and dream of them shimmering beneath a warm summer sky. Their season will roll around soon enough. Get yourself a good dragonfly book, a good pair of bins, and, come June, go to your favourite wetlands. You may just find yourself a new favourite insect there.

Southern Emerald Damselfly

*This blog has been edited since posting to correct the timeline of Southern Emerald colonisation and credit the finder. 

The Aeshnid Dragonflies

 

I love Aeshnid Dragonflies. It was a love affair that probably began at Dungeness in 2010, when the big Aeshna mixta, Migrant Hawker dragonflies, provided me with excellent photography subjects and generally kept me entertained between counting passerines when I was doing my Undergraduate dissertation. I wondered at the speed at which they could climb and dive and turn, more than matching a Helicopter or a Swallow for aerial agility. I watched their hunting flights, the speed at which they could bring down insect prey small and large (ish), and how relaxed and complacent they would become when they perched up to eat and digest. I love the jewel markings like inset sapphires in their long, knitting-needle abdomens. I love their huge, wrap around compound eyes, affording a wide field of vision to spot prey and predator alike.

Aeshna juncea nomming a Speckled wood Butterfly. Isle of Mull, June 2014

These big insects are predators and no mistake. During their few short weeks on the wing they grab prey up to the size of large butterflies off the wing, and I have seen a Common Hawker (Aeshna juncea) eating a Speckled Wood Butterfly on a sunny June day on the Isle of Mull, completely unbothered by me and my camera lens, fixated on dismantling and hungrily devouring the smaller insect. They are hunters in their youth, too. A. juncea can spend a couple of years as a larva, in the small ponds in which it lives, hunting even small vertebrates like tadpoles and froglets, a veritable tiger among the pondweed. They can live at considerable latitudes, their growth limited by the low temperatures, while cogeners in Southern Europe can have several broods a year.  A. juncea is sometimes called the Moorland Hawker, for the Northern and Upland habitats in which it can thrive.

Migrant Hawker, Otmoor, Oxfordshire, August 2022

Aeshnids in the British Isles come in two genera, Aeshna, a name which Wikipedia claims might originate from a misprint, Aechma being ancient Greek for Spear, presumably in reference to their elongated shape and predatory nature, and Anax, from the ancient Greek for a king or leader, the emperor dragonflies. Both these genera are widely distributed around the globe. They are members of the order Odonata, infraorder Anisoptera, and now thought only distantly related to the similar, huge insects of Carboniferous palaeontology, though in the air they do appear true heirs to these prehistoric monsters. In adulthood all are predatory, and most are territorial, individuals patrolling stretches of hedgerow or pond side and tolerating no insect intruders.  Their larvae, called Nymphs, are, like other odonata, ambush predators, lurking in the pondweed and snatching passing water life. As large insects, they can take multiple years to mature.

Female Migrant Hawker, Essex, August 2022

In the Autumn, our most numerous Aeshnid here in Southern England is the Migrant Hawker (Aeshna mixta) which can be found, sometimes forming large groups of individuals, terrorising the little midges and such which gather in glades and on open rides, sometimes far from the water in which they started their lives. These groups can reach some numbers, and, unusually for dragonflies, they can be surprisingly tolerant of each other, seldom engaging in the high pursuit, rolling, dangerous territorial fights which seem to occupy a lot of time for other species. The Migrant Hawker only spends one year as a larva, emerging in late summer and early Autumn and remaining on the wing until mid-November where we are now.  It’s first segment is identified by a ‘golf-tee’ shaped marking. Sometimes a larger Southern Hawker (Aeshna cyanea) appears, and menaces them. This beast, which once bred in our Essex garden pond, is substantially larger than the migrant hawker, and tolerates few rivals. Its abdomen is jewelled in Blue and Green.

Elderly Migrant Hawker being 'mobbed' by a Willow Emerald Damselfly. RSPB Rainham Marshes, Essex, October 2021

More recently, Southern England, and my home county of Essex in particular, has become a hotspot for a new Aeshnid. The Southern Migrant Hawker (Aeshna affinis) is increasingly common on the ditches and grazing marshes which line the Essex coast from the Thames to the Stour. This beauty has a thorax washed with blue over a base of green, and a vivid blue abdomen. Its segment one is marked with a ‘Deadpool mask’ marking, recalling the face of Marvel’s sweary superhero.  First identified in the county in 2007, my summer was full of these stunners, fighting and breeding over clubrush and reed lined ponds and ditches in July and August. By my understanding, how long the Essex population spends as a larva remains unclear, though it is probably one year, and this incredibly handsome invertebrate is one of climate change’s winners, locally at least, benefitting from the hotter summers.

Southern Migrant Hawker, Bower's Marsh, Essex, July 2022

In contrast, Brown and Norfolk Hawkers are relatively dull in colour, large and robust, the Brown Hawker (Aeshna grandis) having brown flushed wings, and the Norfolk Hawker (Aeshna isosceles), now found much more widely in the UK than confined to Norfolk, though still considered rare and localised. The Norfolk Hawker has big, green eyes, and is relatively widespread in Continental Europe and North Africa. The Brown, which is large, has two pale diagonal stripes on its thorax and subtle blue eyes. It too is doing well, expanding its British range.

Emperor Dragonfly, male, Bowers' Marsh, Essex, July 2022

Though recently the Lesser Emperor (Anax parthenope) has been confirmed breeding in Southern England, for a long time the only Anax dragonfly in these islands has been the spectacular Emperor Dragonfly (A. imperator). This big, green and blue Dragon, by some measures the largest species in Britain, is common and familiar. I have witnessed them ovipositing in borrowdykes on the Essex marshes, and in city centre park ponds. The male has a solid, muted green thorax and a bright blue abdomen, distinctive by their size. They fly in high summer, into August, and range across much of the country.  

Southern Migrant Hawker, Essex, August 2022

Aeshnids form a most impressive family of insects.  Predators, aerobats extraordinaire, survivors and thrivers, wonders and jewelled terrors of freshwater bodies and their environs, nymph and adult. And even in November, it is not too late to see the distinctive shape of a Migrant Hawker, patrolling the hedgelines near you.

Wanderings in the Strangest Summer- A Trip South, 17th-21st July 2020, Part 1.

Stretching the definition of 'on the way' a little, I stopped off at Lakenheath Fen in Suffolk on my way to Upminster, from Wirksworth. Lakenheath Fen sits close to the USAF base at RAF Lakenheath, in the Brecks close to the Norfolk/Suffolk/Cambridgeshire tri-point. A new wetland, a masterpiece of habitat creation, its reedbeds and open water were once carrot fields, and they sit alongside poplar plantations, where Golden Oriole once bred, indeed, they were among the last sites used by this species in the country.

Peacock Butterfly at Lakenheath Fen

I was welcomed by friendly RSPB volunteers, who informed me the site was now fully open, the reserve open access until Dusk, and served me a welcome coffee, before I headed up beside the river Great Ouse, looking across its Lapwing and Godwit infested washlands. The thistles presented a wonderful display of Peacock and Red Admiral butterflies, so many of these magnificent but familiar big nymphalids on the wing. I made my way to the Joist Fen viewpoint, which was surprisingly busy, with a lot of people about including a man with a big camera and a sound lure, a device playing Bearded Tit contact calls. These are highly frowned upon, and thought to disrupt birds breeding behaviour, or at least distract them from foraging. After some dirty looks from the assembled he went on his way, and, satisfyingly, no sooner had he done so, than the Bearded Tits arrived, affording us brief but clear views of these charming, mustachioed denizens of the reedbeds, busy, little brown birds with reed-brown bodies, long tails, and in the males, blue-grey heads and elegant black mustaches.

Red Admiral Butterflies and Red Soldier Beetles at Lakenheath Fen.

The Beardies did not hang around, and bird-wise, the viewpoint was quiet, with no cranes to be seen, these being the other star bird associated with Lakenheath, so, making my walk a circuit, I walked back along track and boardwalk, beside open water, and yet more butterflies including a gorgeous Brimstone, toward the visitor centre.

Ruddy Darter Dragonfly at Lakenheath Fen

View of the Great Ouse, Lakenheath Fen

After this I took another, shorter circuit, up to the New Fen Viewpoint, where a Bittern flew by, and Scarce Chaser dragonflies, males tarnished cobalt blue, staining black according to their age, females a shade of gold in the sunshine, alighted on the benches. and Common Lizards sunned themselves on the boardwalk. There were bright scarlet Ruddy Darters here too. Several Marsh Harriers flew lazily above the nodding reeds, these still uncommon raptors now almost ubiquitous in the Anglian fens, and deep in the reeds, Reed and Sedge Warblers, the rave DJs of the wetlands, sang their ever changing, but distinctive, rhythmic song.

Male (top) and Female (bottom) Scarce Chaser at Lakenheath Fen.

I looped around the family trail, taking in the less explored part of the reserve, the air alive with the song of whitethroat, and more spectacular nyphalidae on the wing. Then I headed on my way, back across the country to the M11, the songs of Acrocephalus warblers still ringing in my ears.

Small Copper at Lakenheath Fen

Birds Seen: Canada Goose, Greylag Goose, Mute Swan, Mallard, Tufted Duck, Pheasant, Great Crested Grebe, Bittern*, Grey Heron, Little Egret, Cormorant, Sparrowhawk, Marsh Harrier, Moorhen, Coot, Oystercatcher, Avocet, Black Tailed Godwit, Black Headed Gull, Lesser Black Backed Gull, Common Tern, Stock Dove, Woodpigeon, Green Woodpecker, Kestrel, Jay, Magpie, Carrion Crow, Blue Tit, Great Tit, Bearded Tit*, Swallow, Chiffchaff, Sedge Warbler, Reed Warbler, Whitethroat, Wren, Blackbird, Greenfinch, Goldfinch, Reed Bunting.

Banded Demoiselle (female) at Lakenheath Fen

Butterflies Seen: Near Visitor Centre: Small Copper (3) Small Skipper (4), Green Veined White (9), Red Admiral (19), Meadow Brown (19), Ringlet (2), Peacock (74), Large White (27) Small Tortoiseshell (1) Brimstone (2) 

Near Joist Fen: Small Copper (1) Comma (1) Gatekeeper (1) Green Veined White (10) Meadow Brown (22) Small White (2) Large White (17) Ringlet (4) Red Admiral (26) Peacock (50) Large Skipper (1) 

Near New Fen: Speckled Wood (2) Large Skipper (2) Meadow Brown (8) Green Veined White (2) Large White (2) Peacock (14) Red Admiral (9) Comma (3) Brimstone (1) Small Skipper (3) Small White (1) 

Other notable wildlife: 
Scarce Chaser, Emperor Dragonfly, Banded Demoiselle, Blue Tailed Damselfly, Ruddy Darter, Common Lizard, Rabbit, Grey Squirrel.

 

Cranham Marsh, Essex, 19th July 2020

Cranham Marsh is a small Essex Wildlife Trust reserve, a stones throw from where I grew up, indeed, a short bike ride for the younger me, and a place I loved to visit through my teens and 20s. Indeed, I credit walks at Cranham Marsh with reigniting my fascination with wildlife after a few challenging years I had when I was at University, first time round. It's not famous like Lakenheath Fen, but it is important in my personal headcanon of nature reserves. It has been well used by people, barely sitting outside of the leafy suburb of Upminster, but is by and large treated with the respect it deserves by many people, and I hope continues to inspire suburban people to get out and enjoy wildlife.

Mumsie's Brown Argus. 

It was another gloriously sunny day, and there were abundant butterflies on the Hemp Agrimony and Centaurea and the thistles, including a smart Brown Argus (Aricia aegestis) which Mumsie spotted, and a number of bright Common Blues and Holly Blues, all tiny lycaenid jewels in the long grass and among the flowers.

Peacock on Hemp Agrimony at Cranham Marsh

Jays, and Rose Ringed Parakeets, now ubiquitous around greater London, were calling, and a gorgeous Field Vole, Britain's most numerous mammal, but seldom seen, a small dark ball of fur, ran across the path. It was rather a trip down memory lane. 

Cranham Marsh nominally hosts wet grassland habitat, perhaps better described as seasonally wet, seldom holding much water into the high summer.  In this spell of hot weather we were enjoying, parts of the reserve seemed parched and dry.  The site is said to have suffered from the building of the M25, but it still hosts remarkable wildlife. 

I visited again on the 21st, just as a place to enjoy a cold beer and a bench with an old friend in the scorching sunshine, and on that visit, I managed to snap an unexpectedly interesting photo of bees, on the thistles.

Honeybee and Buff-Tailed Bumblebee on Thistle at Cranham Marsh. 

Birds Seen: Black Headed Gull,  Feral Pigeon, Swift, Green Woodpecker, Kestrel, Rose-Ringed Parakeet, Jay, Magpie, Carrion Crow, Whitethroat, Wren, Blackbird, House Sparrow, Dunnock, Chaffinch, Goldfinch. 

Butterflies: Comma (6) Green Veined White (22) Large White (20) Gatekeeper (12) Red Admiral (4) Meadow Brown (23) Speckled Wood (1) Ringlet (14) Small Skipper (11) Brown Argus (2) Common Blue (6) Peacock (7) Small White (11) Holly Blue (1)

RSPB Bowers' Marsh, Essex

I took half a damp day, the sun gone, to walk around this damp piece of land, an RSPB reserve sandwiched between the Essex town of Pitsea and a landfill site, to walk a circuit, and tick more bird species than I did at their fenland flagship, in drizzling rain. 

There were a few runners and dog walkers taking their permitted exercise, and to my surprise, a few motorcycle scramblers about. Under the partial reopening permitted, I caught the reserve just before it was closed again due to antisocial behaviour.

Record Image of Black Necked Grebe at Bower's Marsh. 

The birds were the stars of the day, and there were many, Avocets had fledglings on the islands in the scrape. A single Black Necked Grebe, an attractive, relatively scarce species, with Macaroni Pengion ear tufts, a distinct, sharply sloping forehead, a ruby red eye set in a black head and neck, and rich chestnut brown flanks while resplendent in breeding finery, hung out on the water with a small band of Pochards, diving frequently. In the reeds at New Marsh Viewpoint, I again encountered Bearded tits, for the second time in three days! A smart male, and two youngsters made their way between the reeds.  Common and Green Sandpipers were on a black and rubbish-strewn patch of water on the other side of the fence separating me from the landfill site. A Marsh Harrier made occasional flybys, putting all the waders to flight.

Record Image of Bearded Tit

Another highlight was the Yellow Wagtails. Summer migrants, this flock included a couple of dapper yellow adults, bright, flying dandelions, and a couple of muddy yellow and olive youngsters.  Yellow Wagtails are a widely distributed and variable species, with geographically distinct races, though these were true yellow wagtails, the near-endemic British subspecies, Motacilla flava flavissima, and had probably bred locally, though in a few months they would begin their long autumn migration to sub-Saharan Africa.  

Despite the grey, there was a Marbled White butterfly on the wing too, big and blousy, blown about by the breeze. 

Birds Seen: Canada Goose, Greylag Goose, Mute Swan, Shelduck, Mallard, Teal, Pochard, Tufted Duck, Black Necked Grebe*, Grey Heron, Little Egret, Marsh Harrier, Coot, Oystercatcher, Avocet, Lapwing, Black-Tailed Godwit, Common Sandpiper, Green Sandpiper, Redshank, Black Headed Gull, Common Gull, Herring Gull, Lesser Black Backed Gull, Common Tern, Stock Dove, Woodpigeon, Magpie, Jackdaw, Carrion Crow, Blue Tit, Great Tit, Bearded Tit, Skylark, Swallow, Sedge Warbler, Reed Warbler, Whitethroat, Starling, Blackbird, Robin, Stonechat, House Sparrow, Yellow Wagtail*, Pied Wagtail, Chaffinch, Greenfinch, Linnet, Goldfinch, Reed Bunting. 


Warley Place, Brentwood, Essex, 19th July 2020


I spent a couple of hours with the family bimbling around one of Mumsie's favourite spots, Warley Place near Brentwood, a fascinating reserve near Brentwood. The reserve's origins are interesting, they form the grounds of a long demolished stately home, once occupied by Ellen Wilmott, keen gardener and plant hunter. Many of the exotic plants she grew in her gardens still survive, though under a canopy of mature trees, the house, unoccupied since before the second world war, was demolished in the 1960s, and the gardens left to fall to ruin, though elements of them have since been partially restored. The historic structures which still stand, parts of a conservatory and a coach house, are maintained in an as-is condition, and the Edwardian glory of the gardens can easily be imagined.

Rutpela maculata on cultivated Rose. 

Two hides stand on the site, overlooking small bodies of water, one a garden pond, the other the irrigation system beneath a long demolished hot house, each with bird feeders outside, attended by Great Spotted Woodpeckers and a few common passerines. Ginkgo biloba grows alongside cultivated roses and bamboo, relics from Ellen Wilmott's day, alongside self seeded secondary woodland.

Among the curious creatures we found was a beautiful longhorn beetle,which Dad spotted atop a rose flower. We identified as Rutpela maculata.  

Birds Seen:  Moorhen, Woodpigeon, Great Spotted Woodpecker, Green Woodpecker (H) Jay, Magpie, Carrion Crow, Coal Tit, Blue Tit, Great Tit, Blackbird, Robin. 

Butterflies: Red Admiral (2) Meadow Brown (4) Green Veined White (2) Speckled Wood (1) Ringlet (1) Gatekeeper (2)