Orthetrum cancellatum (Linnaeus, 1758)
Status in Britain and Ireland:
locally common; increasing
Overall body length 44-50mm
Hindwing length 35-41mm
Late May to mid August
Photograph © B. Kemp
Male Black-tailed Skimmer
The abdomen is powder blue with yellow- orange crescent shapes along the sides. Segments 1-2 are brown and segments 7-10 are black. The abdomen tapers from segments 2-3 to a very narrow segment 10. The thorax is brown-black with incomplete and fairly indistinct black antehumeral stripes. The wings are clear with a yellow costa and short black pterostigma. Small yellow antenodal cross veins are also visible (running perpendicular to the length of the wing). The eyes are greenish blue and the legs black. Immature males look like females with 2 black stripes running down the length of the abdomen. Older specimens may well have dark patches on the abdomen where female legs have rubbed off the pruinescence during copulation.
Broad-bodied Chaser and Scarce Chaser though similar have distinct patches of colour at the wing bases. The Keeled Skimmer does however have clear wings, but also more prominent antehumeral stripes and distinctive ochre pterostigma. In addition the Keeled Skimmer is far less common than Black-tailed Skimmer being associated with acidic heathland sites.
Unlike Chaser species, the Black-tailed Skimmer is often seen basking on exposed soil or stones. The males are territorial and will aggressively defend an area by flying out low over the water from a perch and chasing off intruders. When a female arrives she is grabbed and copulation occurs either airborne in a matter of seconds or at a perch amongst vegetation. Subsequently the female oviposits alone but with the male in close attendance. The tip of the abdomen is dipped into the water to release the eggs.
Ponds, lakes and slow flowing rivers that are open and with margins having bare soil and stones and little vegetation. Often a pioneer of new sites with bare banks.
Recorded in 1950, 1978 and in the early 1980’s at Whixall Moss. Also recorded in 1984 at Wem Moss. Despite records of exuviae being found at Berrington Pool in the 1990’s, sightings remained few and far between and Lockton et al., (1996) described this species as casual and uncommon. They did note however that a number of recent records had been made in south east Shropshire at Dudmaston and Chelmarsh Reservoir and wondered if breeding colonies would persist. The current distribution map looks markedly different with records spread across the county. This species is currently classed as local though may well be regarded as common and widespread in the near future. In 2015 records doubled those of the previous year and covered 3 new 10km squares in the county. The recent National Atlas (Cham et al., 2014) showed this species to be expanding in range north and westwards which would certainly explain the surge of recorded sightings in Shropshire.
Where to see in Shropshire
Venus Pool, Dudmaston, Cole Mere, Whixall Moss, Brown Moss, Montgomery Canal, Discovery Centre at Craven Arms, Wyre Forest near Silligrove.