After making a batch of lamb dhansak and leaving it simmering in the slow cooker, I decided that it was high time I took myself off on a little invertebrate hunt. I set off for Trench Wood, but half way along the Roman road, and still half an hour away from my goal, I suddenly realised I was so tired that I couldn’t be bothered to drive any further. So I turned into Barton, and went to the Heart of England Forest and its River Avon walk instead.
In theory, demoiselles could live on into October, if the weather holds. In practice though, that never happens – not here at least, during the seasons I’ve been observing them. Back in mid-June there were too many Banded Demoiselles to count along this stretch of the Avon, and I saw maybe thirty Beautiful Demoiselles on the little stream that runs through the Forest and feeds into the river. Today though, there were perhaps fifty Banded and six Beautiful Demoiselles in the same area. As you can probably imagine, this population crash made me feel quite sad, but we are where we are, and there’s no point pre-mourning the end of the season before we’re even into August, so I stiffened my sinews and tried to concentrate on getting the best shots I could of the specimens that remain.
This male Beautiful Demoiselle gets top billing tonight because I haven’t posted one since I found them at the bottom of our garden during the 2020 lockdown (though I did post a female about six weeks ago, photographed in almost exactly this same spot). I’m pretty happy with this image, though another step forward would have given me the option to crouch a little, get closer to his level, and possibly capture more light coming through his splendid bronze wings. That step would also have taken me onto the very edge of the stream bank though, which I suspected was undercut. I gave the matter, and the shallow but rather foetid water, some consideration, but ultimately the question Are you feeling lucky? received the answer, Mmmmm…. not very. Not today.
Although this is my favourite photo of the day, the extra is perhaps more interesting, in showing some striking behaviour among the Banded Demoiselles at the river. It’s quite common for a loose male to attempt to interrupt a mating pair, but this was the first time I’ve ever seen one try this hard to wrestle the female away from her mate, and I suspect it may be a sign of desperation, as their season moves towards its close and the availability of females reduces.
All Odonata breathe through special holes called spiracles in their exoskeletons, and they can drown if they become submerged, or even caught in the surface tension of a body of water. Demoiselles are unusual though, in that the males will voluntarily throw themselves onto the water surface in order to attract a female; and the females (which oviposit alone, though with their mate in close attendance to prevent them being seized and re-inseminated by a rival) will submerge while laying their eggs, breathing air that they take under the water with them, trapped between their wings. Given this unusual relationship with water, this scene was perhaps not as dangerous as it looked, but still, the amount of thrashing, fluttering, and splashing that went on for almost half a minute had me convinced that someone was probably going to end their days here.
Eventually though, the male in possession lifted off the lily pad, hauling both his mate and the interloper out of the water, and after a final bout of aggressive fluttering by both males which fully submerged the female, the pretender gave up and released her. All three then flew towards the river bank, and I lost sight of them in thick foliage.
I was so exhausted by all this drama that I ended my walk at this point, and went home for a cup of tea. I suspect that the female Banded Demoiselle might have liked to do the same thing.
