The keeled skimmer (Orthetrum coerulescens) is a specialist of wet heathland and bog, especially in areas where sphagnum mosses thrive. As a result the heathland areas of Dorset are one of its strongholds in this country and it is, nationally, quite rare. Where it does occur, however, it can be abundant. Easily dismissed at first sight as a broad-bodied chaser because of its bright blue body (the male that is) closer examination, if it settles, will show a narrower body tapering to a point at the tail. It also lacks the yellow side markings on the abdomen. The keeled skimmer tends to fly low over the water of its chosen pond, skimming over it in fact. It has a rapid and unpredictable flight pattern, usually near the edge of the water, where the pond side vegetation grows. The male settles on a favoured perch to monitor activity on their patch but show interest in intruders rather than out right confrontation, unlike the aggressive broad-bodied chaser. The females are green and have a thin, less tapered body.
The Nature of dorset 