Saturday, August 27, 2011

A change of plan...

I had intended this blog entry to be about my visit to Thornden Woods but at long last a few dragonflies have started to appear and so I thought perhaps Thornden will wait for another day, whilst I share some shots of Odonata.


Click on any picture to enlarge.


This Common Darter as it's name suggests is a commonplace dragonfly but this year has been exceptional for the lack of most species locally. This is a male.





A full profile view showing the curved abdomen.




A dorsal view really shows off those fabulous wings too.





Our summer in this corner of the world hasn't been anything to write home about (which is just as well because I haven't been anywhere!). Today must have been reasonably warm though because I saw a dragonfly exhibiting a fabulous behaviour pattern that only takes place in warm sunshine.


It's known as 'obelisking' and involves the dragonfly standing in a head-down position, with it's abdomen pointing skywards. The purpose seems to be to stop the dragonfly from over-heating.


'Obelisk' position.


The dragonfly pictured above is of the same species as the first pictures but is a female, as you can see these are a lot duller in colour, as are the immature males, so much so that they can easily be confused with the females.


Although those wings look very delicate, the muscles that control them (which by the way, they can control independently) are not; at full speed most dragonflies can reach speeds of 40 miles per hour. They can hover, fly backwards, shoot vertically up or down and turn within their own body length, making them superb hunters.


A Common Darter on bracken.

And so at long last some dragonflies are to be seen locally. Although I've now seen a handful or so, they have all been the same species. I've had a few fleeting glimpses of other, larger 'Hawker' dragons as well but no close-encounters yet. It'll happen though, I'm sure of it and when it does, you can be sure I'll be there with my camera to record it.

Incidentally, dragonflies have quite a connection with stoneflies; evolution-wise stoneflies are thought to have appeared very soon after dragonflies and as we know, they are amongst the oldest of all insects.
It's thought that stoneflies may be represent an early stage in the evolution of insect flight as they have wings but rarely fly, even when they do take to the air, it's more a case of opening their wings and waiting to be lifted by a gust of wind.

 I'll no doubt be doing a piece on stoneflies next spring, for now though, here's a photo taken during spring of 2011.

A Stonefly.



Finally for now, you may by now be thinking that I've been 'messin' with the blog design/layout again?
Well a combination of frustration at several things that have gone wrong/astray that have been beyond my control, and I've also failed to find a 'fix' for, alongside advice from 'blogger' and other bloggers that I've spoken to has meant that the general consensus seems to be 'keep it simple' and there's less to go wrong, after all it is a free service.

And so that's what I've done, simplified it all and let's hope that from now on it all runs like clockwork and there are no more disappearances or glitches.

Until the next time then...








2 comments:

Paws said...

Very cool pics. I never knew about obelisking that is neat! :)

JJ said...

Thank-you Cathy.
Yes. it's a strange behaviour but obviously does the trick in keeping them cool. Dragonflies are great and there are still so many species yet to find.