Sunday, 29 May 2011

The Quest begins - Part II

So to those difficult blue damsels. The two confusion species I mentioned (Common Blue and Azure) tend to occur in good numbers at the same sites so without getting a decent view of a perched individual it’s unlikely I can make a positive ID. As usual the bright blue and black individuals we have here are males on territory, though it has to be said they are not really aggressive towards each other, though more competitive when a female is on the scene.
There are subtle differences in markings of the males of the two species but THE big diagnostic pointer if you can get a clear view of it is the black shapes at the top of the abdomen just under the thorax (or body). In the Azure this is like a U shape, (just remember azUre) in the Common Blue it is like a mushroom. (coMmon). See illustration below. When I get a photo of the Common Blue I'll do a side by side comparison of the other spottable differences in the field.

Azure - U (left)  Common Blue - Mushroom (right)

Back to the quest and after the initial good fortune with the reds, the weather became rather unkind, sunny patches became few and far between, I was beginning to think I would never get an opportunity but as with the reds a couple of individuals suddenly appeared close by, photographed first to make sure they didn’t get away then viewed through binoculars to confirm both were Azure damselfly, (note U-shape at the top of the abdomen.)

Azure damselfly Coenagrion puella  (male)
There were only around 20 individuals present all told,, mostly on the raft of lilies centre pond, but could only ID the two I photographed with any certainty. Another time for the Common Blues then, not too downhearted though as they‘re not called ‘common’ for nothing.

It’s probably worth pointing out that there are in fact a number of similar blue and black species throughout the British Isles but so far only these two have been recorded in Gateshead (I won’t count the blue-tailed damsel, as it is mainly black and not easily mistaken for the other two) so for now these are all we need to be concerned with. Once I’ve recorded the Common Blue I’ll deal with the females.

Anyway, the sun disappeared altogether shortly after this and the damsels with it, but the pond is very clear here and I entertained myself with watching the fascinating underwater creatures, boatmen, diving beetles, caddis fly larvae, water scorpions, a myriad of creatures I’m not familiar with and quite a few damselfly nymphs as well, but the star sighting was indeed a couple of glimpses of Great Crested Newts as they came up for air before disappearing back into the weedy pond-bottom, vivid orange bellies interspersed with black on otherwise smoky grey bodies and very obvious undulating crests, great stuff!

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