The Darter Dragonflies

As I write, it is grey outside. Mild now the now has melted, but drizzling and chill. Dragonfly season is well over. But it lasted into October, even November with the mild conditions and today feels an excellent day to look back.

Ruddy Darter, male, Essex 2022

At nearly every site I surveyed, the most numerous genus of Dragonfly I encountered, especially as the season pushed on into August and September, was Sympetrum. Specifically, Sympetrum sanguineum, the Ruddy Darter, and S. striolatum, the Common Darter, the former apparently capable of surviving even mildly brackish water conditions, favouring low lying coastal marshland, occurring alongside Scarce Emerald Damselfly (Lestes dryas) and Southern Migrant Hawker (Aeshna affinis). The latter, S. striolatum, is capable of flying well into the season of mists and mellow fruitfulness and is often one of the last dragonflies on the wing. However despite their abundance, and their abundant charisma, this genus seems relatively unexplored in the popular literature.

Ruddy Darter, Male, in Obelisk position as he attempts to lose heat during the heatwave of July 2022. 

These represent the two commonest species of Sympetrum, a genus in the family Libellulidae. Both species are broadly speaking red in the adult male, and gold, fading to brown in the the females. These creatures are, like other Odonata, agile aerial predators as adults, darting from their perches and sunbathing spots to seize small insects off the wing. It is this darting habit which gives them their common name. Their larvae lurk in almost any still or slow-moving body of water you might find.

Common Darter, Rainham Marshes, October 2021

Most numerous in the low coastal marshes of Essex in June and July is the Ruddy Darter (Sympetrum sanguineum),the males vivid, blood-red as the scientific name implies, the females an eye catching straw gold. They are the smallest of the ‘large’ dragonflies (Anisoptera) typically on the wing. They tend to form an assemblage with Scarce Emerald Damselflies (Lestes dryas) and Southern Migrant Hawkers (Aeshna affinis) alongside several of the small, blue damselflies, a habit noted by Brooks and Cham in their excellent field guide, which I found reflected strongly when I had the privilege of carrying out dragonfly surveys for a conservation organisation in the Summer of 2022. The males possess something of a ‘waist’ to the abdomen and can appear club tailed. Legs are jet black and the thorax lacks distinct stripes.

Common Darter, Otmoor, Oxfordshire, September 2022

Common Darter Breeding territories are closely guarded, with adults prepared to chase away any intruders, but away from water, their habitats are different. They like to be in the sun, and pick the sunniest spot they can find, and bathe in it, absorbing the solar energy through their skin. Signage, gateposts and fencing are among their favoured perches, and here they can gather in large numbers, occasionally lifting up, briefly, to grab some passing prey on the wing, or in readiness to flee a threatening shadow, before settling back down again, usually in the same patch of sunshine from which they took off. In Autumn especially, Common Darters can be surprisingly willing to come and sit on an outstretched hand, something I have witnessed and done several times, at a few sites up and down the country. Try it one sunny afternoon. Go somewhere with abundant Common Darters, any still water with adjacent sunlit rides is a good bet, find a patch of sunshine, and hold out a hand.Perhaps these engaging insects will come and visit. Stand calmly; they are completely harmless and will not bite, and they will use you as a sunbathing and bug hunting post.

Black Darter, male, Garry, Isle of Lewis and Harris, Scotland, August 2021

Both Common and Ruddy Darter are abundant and thriving, but another Sympetrum, S. danae, the Black Darter, a specialist of acidic pools on heath and moorland, has shown significant declines in its numbers in recent years. It is still an abundant dragonfly in the somewhat specialised habitats in which it occurs. Our smallest Sympetrum, and indeed our smallest true Dragonfly, shorter than your little finger, the male S. danae is also the only entirely black dragonfly in Britain; the female is black and gold. Like their red lowland cousins they can be confiding and will occasionally perch on fingers. Another upland species, under more extreme threat of local extinction, is the White-Faced Darter (Leucorrhinia dubia), reintroduced since 2010 to Foulshaw Moss in Cumbria, a Cumbria Wildlife Trust reserve probably most famous for its breeding Ospreys. A true specialist, this beautiful insect, with a white frons and a body dappled red and black, or gold and black in the female, they spend their larval development right down among the mass of sphagnum, avoiding open water, or anywhere fish can be found. Like so many species of the North, it is threatened by peat extraction, the abandonment of traditional moorland management, and by a warming climate. The peatland habitats in which these two darters dwell represent an important carbon sink, ever growing Sphagnum, is a real asset in our fight against man-made climate change. Efforts to secure the future of these two little dragons in Britain are efforts to secure the future of our world and ourselves.

White Faced Darter, female, Foulshaw Moss, Cumbria, May 2015

So keep an eye, next summer and into the Autumn, for these species wherever you happen to wander. The two ‘red’ species so numerous here in Essex are common and widespread, flying from May into late October, even November. They are sometimes overlooked in favour of the more glamourous Aeshnids and distinctly fashionable Lestidae damselflies, but I think they have a remarkable charisma of their own.