Tuesday, 29 May 2007

The dragons stir and search for damsels

It’s early morning and there is just enough warmth in the sun’s rays to rouse slumbering dragons. Perched with wings outstretched and hanging motionless on the reeds and sedges are four-spotted chasers and hairy dragonflies. These are perhaps the first of our dragonflies to appear on the wing, to be followed over the coming weeks and months by other species. Also on the wing, floating just above the vegetation like decorated matchsticks, are the first of the damselflies – in this instance azure and blue-tailed damselflies. Once known as the ‘Devil’s Darning Needles’ these tiny creatures will have recently emerged, shedding the skins of their aquatic existence.  It is these creatures that the hairy dragonflies, in particular, will soon be hunting.

Early morning is the best time to really appreciate the beauty of our dragonflies. Perched, not yet at operating temperature, it is possible to make a close examination of them, taking in the jewelled beauty of their apparel, the delicate venation of their wings and their large globular compound eyes. These are an important feature, for all dragonflies are fierce predators – taking anything from small flies to butterflies. Good vision, manoeuvrability and a burst of pace are essential for such active hunters.

Male four-spotted chasers are highly territorial, choosing a suitably prominent perch from which they can launch sorties towards any other dragonfly that wanders into their airspace. If this turns out to be a female four-spotted chaser then a very brief mating will follow, in flight, after which the female will break away to initiate egg-laying. This is one of the easiest species to recognise, with the combination of its dark tapering body and dark wing spots (four on each of the two pairs of wings) there is little else with which it could be confused. Once airborne the four-spotted chaser, as its name may suggest, is a fast flier, busy and energetic as it moves about around favoured still water habitats.

While the four-spotted chasers are mostly still perched on vegetation, the hairy dragonflies are on the wing, actively hunting for prey and patrolling low through the reeds and sedges. They seem to knock into plants; are they trying to flush prey? Related to the other hawkers (a group of dragonflies which includes the migrant hawker, Norfolk hawker and the impressive emperor dragonfly), they are typically ‘hawker-shaped’, fairly stout but smaller and more compact than some of the other species. At this time of the year they are the only hawker on the wing, the males resplendent with an apple green thorax and an enamel blue and black abdomen. Why not check them out for yourself by visiting one of our wetland reserves.

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