There is then a pause of about 30 minutes to allow their legs to harden enough for the next stage when the abdomen is withdrawn. After finding a secure support they redistribute their body fluids, pushing the thorax, head, legs and wings out of the larval skin. Larvae climb up emergent vegetation although some may walk several metres over dry land before finding somewhere suitable to emerge. Most species leave the water during the morning, other than hawkers that do so under cover of darkness. Final-stage larvae sit in shallow water near the margins for several days, getting ready for their final moult and starting to breathe air. To quote a BDS guide, since dragonflies unlike other winged insects do not have a pupal stage transition occurs straight from a larva to an adult. This final larval moult takes place out of water being triggered by day length and temperature. Alas, unable to fly this individual was most likely a goner and would remain where it was until starving or being eaten itself. In such circumstances newly emerged dragonflies are vulnerable to attack by territorial males of other species, drowning from the wash of passing boats or being snapped up by passing wildfowl or other opportunistic birds. Despite flapping twice and altering position on its chosen perch, one wing appeared to be deformed and after two hours it had still not flown and was not moving at all. There can be a 25 to 33% failure rate in this process and indeed all did not appear to be well with our particular Clubtail (pictured above). This clarified why the failed emergence I recorded here two years ago was puny while the second Clubtail encountered then was so much larger and robust ( see here). He explained how on emergence dragonflies pump out their abdomen and wings as part of their breathing function. Being also a former education officer at Wat Tyler Country Park (of Blue-eyed or Southern Migrant Hawker fame) where I had met him previously, I took the opportunity to ask how such a large insect gets out of such a small nymph case. The second observer left after taking his pictures and I was next joined by the county odonata recorder for Essex, Neil Phillips. A patient wait then ensued to see if this specimen would dry off successfully. When I returned to his end he had found a newly emerged Clubtail in waterside reeds. He soon moved on to be succeeded by a second person to whom I talked for a while before checking the concrete wall again. Arriving at about the same time another observer was there ahead of me, confirming there was nothing at one end of the abutment as I did about the other when we met in the middle. So no explanation that the Clubtails have been here for much longer was necessary.įive days later (24th) I made a second attempt. But perhaps surprisingly no-one on that side of the river challenged me about what I was doing or assumed I must be pointing my camera at themselves. Since my last visit a boating club has appeared on the opposite bank (below right) so rather more was going on here than in previous years. That (pictured below, left) was where I went to try my luck again on 19th. So the best chance of observation is usually during or immediately after emergence.Īt Goring they have for many years emerged on the abutment of a bridge carrying the main Reading to Birmingham railway across the Thames (SU606795). Numbers of exuvia (nymph cases) found on the river’s banks are often much greater than actual sightings of the relatively shy adults that either mature in nearby rough ground or relocate quickly to tree tops. Last year I was invited to participate in a British Dragonfly Society survey of the population in this area, but declined because they are just so hard to come by. Of Europe’s six Clubtail species, Common Clubtail ( Gomphus vulgatissimus) is the only one that occurs in the British Isles and the Oxfordshire River Thames from Pangbourne upstream to the west of the county is a traditional stronghold. Newly emerged Common Clubtail drying off in reeds
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