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![Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 2707 W: 139 N: 7809]](http://i1.treknature.com/misc/g-g-g.gif) (24333) | Whitefaces are a relatively small group of dragonflies that is related to Chasers and Skimmers (Libellulidae). They are easily recognised, even at a distance, by their strikingly white faces.
There are five species in mainly NE Europe and seven in N. America.
This is a male Ruby Whiteface (Leucorrhinia rubicunda) found by most lakes in Sweden even well north of the Arctic Circle.
I have never seen a Whiteface hanging in a vertical position like a Hawker (Darner) usually does while resting, though it may do this at night. Instead it may use a stone or plant by the water to watch out for passing insects or its own kind.
This shot shows its ability to move the head upwards to show the white face to another Ruby Whiteface. The white must act as a signal. The WORKSHOP shows it with its head in the normal position.
It is interesting to note what a comprehensive field of vision a dragonfly has: the wide-angle ability of the large compound eyes is enhanced by the ability of the head to move up and down as well as side to side.
The compound eye itself consists of hundreds of small facet eyes. Each facet eye sees a simplified blurred version of the object. But when the object moves these facet eyes can detect movement very accurately. This is why one must approach very slowly when photographing insects. As many insects can see ultra-violet light their colour vision is different from that of mammals.
This was taken with the camera hand-held at a distance of over two meters. After slight cropping and size reduction, the image was selectively sharpened. |
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