Saturday, 26 May 2012

Crouching naturalist, hidden dragon

At HESC, this morning, I was walking alongside one of the ponds and stopped to watch several species of damselfly in the vegetation at the water's edge.

Fortuitously, whilst using my bins to identify a particular individual, my gaze alighted upon a dragonfly larva, tucked away amongst the reeds and ready to emerge as an adult dragonfly after two years underwater.

By the time I had deployed my camera, the action had started, the larval cuticle splitting behind the eyes and along the upper surface of the thorax.

8.14am - the thorax bursts through the larval skin
8.15am - the head and eyes are withdrawn from the larval skin
8.16am - the thorax is now free of the larval skin
8.17am - the first few segments of the abdomen emerge
8.18am - as the adult hangs backwards, the compressed wings can now be seen
8.20am - the breathing tubes linking the adult's thoracic spiracles to openings in the larval skin are breaking
8.26am - a period of quiescence follows whilst the legs harden in the sun's warmth
8.36am - the adult springs forward and grasps the top of the larval skin
8.36am - the remainder of the abdomen is now withdrawn from the larval skin
8.36am - the pale, newly-emerged adult sits on the now empty larval skin or exuvia
8.40am - body fluid is pumped into the wing veins to expand the wings
8.42am - bigger...
8.48am - and bigger...
9.05am - and bigger...
9.12am - until they are fully inflated
9.27am - the fluid is now withdrawn from the wings and used to pump up the abdomen
9.42am - once the thoracic muscles are warm enough, the wings snap open for the first time
9.47am - wings and body harden in the heat of the day and the body starts to develop colour
9.53am - the wings are now starting to look capable of flight
10.01am - the adult dragonfly adjusts position and reveals the characteristic wing markings of a Four-spotted Chaser 
10.10am - nearly two hours after emergence commenced, the adult dragonfly takes her maiden flight and moves to a safer position in full sun
During this time, I was joined by Our Lass, who played her part in an excellent morning's odo-ing by finding a Banded Demoiselle in the Centre garden. Other sightings included Hairy Dragonfly and a host of damselflies: Large Red, Common Blue, Azure, Blue-tailed and Red-eyed.

Another visit in mid afternoon added Broad-bodied Chaser to the total, making 9 species for the day. Odo-tastic!

10 comments:

lyrical lady said...

Well captured, Flower (as they say in t'North - Snap Dragon in this instance)!
What a spectacle, and what a good morning's work for both of you :)

holdingmoments said...

Fantastic sight to see, and great sequence to capture it all. A real magic moment.

Imperfect and tense said...

Paying for it now. Heatstroke :o(

Imperfect and tense said...

Nearly missed it though. I hadn't seen a dragon all morning and was almost back to the car park and on my way home for breakfast.

Tales of a Bank Vole said...

Ah! So thats how you do it - wait until they are unzipping their sleeping bags and hanging around like slothful teenagers. Muggin's patiently waited whilst three of the little buggers orbited his head, waiting for one to land. Unfotunately knees gave out before one had the sense to park itself in front of the lens.Insects Bah!

Imperfect and tense said...

Good analogy, my favourite odo-sceptic. Pertinently, one of the redeeming features of dragons and damsels is that they aren't up and about until it's warm enough. None of this dawn chorus malarkey that birds do. So I can usually have a leisurely breakfast before heading out for a spot of odo-ing , as indeed I did the following day.

Tales of a Bank Vole said...

Cracked it today with a 4SC, you can see on me BV Flickr

Imperfect and tense said...

They can be quite obliging.

sarah said...

You just happened across this? How lovely! Thank you for sharing!

Imperfect and tense said...

Well, it doesn't matter how much you plan, sometimes stuff just happens. Right place, right time. And you're right about hawkweed.