Saturday 5 March 2016

Hairy Dragonfly Nymph Update

I have spent a good few hours during the past few weeks observing the Hairy Dragonfly nymphs in my indoor tank during the evenings. This normally involves a cup of tea, my LED light on my phone and a comfortable chair. I think the family think i'm nuts as I sit for periods studying the tank in the darkness and a look through to them in the living room normally get a few raised eyebrows and various gestures! On the other hand, I have had a great time, watching them going about their business and trying to learn something about their behaviour if I can. During the week, I arrived home after work to see that a male Hairy Dragonfly nymph had shed its skin and this will no doubt provide more photo opportunities for me in due coarse. As far as observations, what have I learnt then so far? Well, as mentioned before, during the day they tend to spend their day upside down, sometimes tight against a stick if possible where they can be hard to see but other times, on the edge of weed with just their heads sticking out. No doubt a good place to catch unwary prey as it passes. What has most surprised me though is their choice of prey. In the tank along with 2 other Hairy Dragonfly nymphs, there are a good number of damselfly nymphs of various species. Initially, I was not sure if they would end up as food for the Hairy Dragonfly nymphs but this has not been the case. In fact, I have not seen one attack on a damselfly nymph despite lots of watching. I have seen them walk right up to the damselfly nymphs and even walk over them. I perhaps thought that if they stood still, the Hairy Dragonfly nymph may not see them but I have seen instances where the damselfly nymph slowly walk off, still with no attack. What does surprise me is that quite often the 3 Hairy Dragonfly nymphs can be very close to each other and don't seem to mind each others company. I have not seen any aggression towards each other which I thought I would do. Maybe the key to the prey item is that it has to be moving quite a lot. I have dropped in a few cut up worms of an evening and this has brought on quite a few attacks. The Hairy Dragonfly nymph turning its head in the direction of the prey and stalking it until its in range and then within a blink of an eye, launching an attack. Its surprising still how unsuccessful they can be at missing prey but a few I have observed have gone back for another go. This has given me the chance to watch an attack at close range and using my Opticron 10X field lens, get a very close few of them feeding if they are close to the glass. Another observation made during the week is that on a few occasions I have seen one reverse up some weed until its rectum (bottom to be polite) is ever so slightly above the water. I know that dragonflies breath through their rectum and is this a sign I wonder of them starting to make the transfer of breathing air as they approach emergence in late April or something else? Whatever the answers to the questions, it has given me many hours of great viewing and a growing education into their secret lifestyles. I have slowly found myself getting obsessed with this species and really hope I can photograph an emergence sequence of this species. Most literature suggests they emerge early morning. Does this mean 5am or 8am? I just hope that I don't miss them and am not at work when it all begins. I shall have to regularly check early mornings when the time arrives hoping I can witness the whole event. I spent the afternoon today photographing the male Hairy Dragonfly nymph which is in superb condition and freshly coloured and ended up with some of my best shots of this species to date. The obsession will no doubt continue.........!






Hairy Dragonfly Nymph (male)

10 comments:

  1. It must be fascinating to see how they evolve.

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    1. It certainly is Anne. Very interesting and best of all, I can do all this from the comfort of my own home in the warmth.

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  2. I love your photography, the way that each one seems to have its coming back of life.

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  3. First rate observations. Is there a venue for publishing this sort of thing? It would be a shame for your data to be undocumented in a more permanent form.

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    1. Many thanks Wilma. I post most info on a firum called 'UK Dragonflies' and also pass on photos and links to my blog to the 'British Dragonfly Society'. Hopefully they find the info useful and will use if necessary. I'm due to have some photos orinted in their next magazine which should be interesting.

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  4. Superb work there, Marc, and some extremely interesting observations. I look forward to seeing your images in print in the BDS magazine.

    Best wishes - - - Richard

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    1. Many thanks Richard. Like you, i'm looking forward to receiving my copy soon. I just hope they are in there!!

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  5. Top post Marc. Excellent piece of wildlife observation work.

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    1. Cheers Warren. A lot to be learnt still I think on their secretive lifestyles.

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