Dragonflies

A Living Flash of Light

On a bright, clear morning the slow-witted naturalist has a chance at a half-decent photograph because the temperature is dropping.

Southern Hawker at Rutland Water last week.

As the year progresses, the remaining dragonflies are slowing up, getting up later, flying less frenetically and sitting around more — low in a bush in the morning sun, trying to warm up.

The only other chance is very early in the morning or shortly after they have emerged, as Tennyson wrote,

“…An inner impulse rent the veil

Of his old husk: from head to tail.

He dried his wings: like gauze they grew;”

The broad bodied chaser is common around our little pond in Mid-Wales — appearing early in the summer and active for a long time. The southern hawker is more dramatic and is aggressive, indulging in arial skirmishes with intruding males along the closely guarded stream-side territory along which he patrols. Passing by every few minutes, easily seen but almost impossible to photograph. “A living flash of light…”

I do my best!

The southern hawker (above) looks so alien with his “plates of sapphire mail” — it is only the fact of scale that prevents me running from this sci-fi inter-stellar gunship as he casts his sinister shadow then disappears in a flash to another dimension.

This pristine brown hawker was drying his wings at Woodwalton fen last summer.

Not to be confused with this rare bird!

The rare Norfolk hawker, with his green eyes and tell-tail little yellow triangle on the first abdominal segment, between his back wings.

We spotted him at Hickling broad this year while we were looking for swallowtail butterflies.

Dragonflies

Damsels, Dragons and lakeside chivalry!

It is quiet in the woods — the leaves of the canopy obscuring the birds hopping silently, keeping a low profile as they raise their young and avoid predators. But there is a hum of insects today in the swingeing heat — bumble bees, honey bees, wasps, flies and beetles dance in the sunbeams that penetrate the woodland. Clambering over the late summer blooms, they feed and pollinate as they go, pausing to clean the stick blackberry juice from their feet.

Near the ditches and the ponds the Dragonflies patrol — a great big hawker zooms over the pond then starts to patrol its margins hovering a meter or so above the water, whisking himself away in a flash of yellow and blue just as I find him in the view finder. Fortunately Bill has had more luck (or expertise) and these are mainly his photos.

Dragonflies and damselflies spend most of their lives in water as fierce, carnivorous larvae or nymphs. Damselfly larvae have fanned tails which are gills but dragonfly nymphs take in water through their rectums where they have internal gills (when in difficulties they can fire out water and jet propel themselves from danger). They gradually grow, moulting their skins as they get too small, until just before their final moult, when they heave themselves out of the water up some twig or reed and start to breath air — then something amazing happens.

They do not pupate like butterflies –withdrawing into a casket to re-organise their bodies for an aerial life. The skin of the living nymph simply splits and its adult self hauls itself out!

Southern Hawker, one of the larger dragonflies, having an “out of character” rest.

Here is a female Southern Hawker — generally females and immature males are harder to identify

Adult dragonflies like the Southern Hawker are very territorial so you will usually only see one on a particular stretch of pond bank except when an interloper enters his territory when there will be an aerial skirmish — a dog fight — the resident male seems usually to prevail and the interloper withdraws to find another territory. When a female appears the male will try to mate with her, grabbing her by the scruff of the neck with claspers on the end of his abdomen. If she is willing she curls her abdomen round to the accessory genitalia on the ventral side of his abdomen just below his waist where he keeps his sperm — thus they form a conjugal wheel or copula. You will see them flying, conjoined like this in tandem. They lay their eggs in water or on submerged vegetation depending on the species. Sometimes the male guards the female while she lays but in some species you will see them, still in tandem — the male holding the female by her neck and dipping her tail into the water to lay, then pulling her out — escaping the powerful surface tension of the water — to dip her in at another location, spreading their bets and increasing the chances that their offspring will survive.

Large Red Damselflies — The chivalrous male holding onto his mate as she lays her eggs

Another larger dragonfly is the Brown Hawker with its orange wings seen here at Woodwalton Fen.

The Common darter is smaller but widespread in lowland habitats often seen basking in the sun on brambles or bare ground.

Different species of dragonflies fill different niches in the water-side world. Hawkers, skimmers and darters prefer standing water whereas the large red damselflies like bogs and ditches. The beautiful demoiselle (that’s its name) and the banded demoiselle like running water like the stream in our valley. Damselflies perch with their wings folded, are smaller and daintier, flutter more weakly and have eyes that are more widely spaced — the eyes of dragonflies meet in the middle.