Strensall Common (North Yorkshire) – 11/08/12

Today saw me visit a new site, as part of the organised joint field trip to Stensall Common, by the Yorkshire Branch of the British Dragonfly Society and Ryedale Natural History Society. The main focus of this trip was dragonflies, though there was plenty of other interest for the seventeen people who attended.

Strensall Common

The most abundant species was Emerald Damselfly Lestes sponsa, with many paired up and ovipositing into the Juncus stems, one small pool holding little vegetation having several pairs on single stems. The most productive pond was in a woodland clearing and it was here that we encountered all the species. “Blue” damselflies were found in small numbers with Common Blue Damselflies Enallagma cyathigerum being the most numerous here, followed by Azure Damselfly Coenagrion puella and Blue-tailed Damselfly Ischnura elegans. It was at this pond that the larger species put in an appearance, as the sun finally came through. A single male Emperor Dragonfly Anax imperator was patrolling the pond and was finally joined by an ovipositing female, the male making several attempts to pair up, without success. A female Brown Hawker Aeshna grandis was flying around the perimeter, trying to find a suitable place to oviposit. A male Common Hawker Aeshna juncea also joined the scene looking out for females in the emergent vegetation around the edges. Whilst observing the hawkers, an unexpected species made a brief appearance, in the form of a female Banded Demoiselle Calopteryx splendens, which had wandered away from its more usual habitat. Four-spotted Chasers Libellula quadrimaculata were still in evidence with several seen, though these are now rapidly nearing the end of their season. Finally three species of “darter” were observed, Black Darter Sympetrum danae being the most numerous with many pairs “in-cop”, with lesser numbers of Common Darter Sympetrum striolatum and Ruddy Darter Sympetrum sanguineum also displaying breeding behaviour, with pairs ovipositing in tandem.

Emerald Damselfly - Lestes sponsa

Emerald Damselfly – Lestes sponsa

Emerald Damselfly - Lestes sponsa

Emerald Damselfly – Lestes sponsa

Common Blue Damselfly - Enallagma cyathigerum

Common Blue Damselfly – Enallagma cyathigerum

Black Darter - Sympetrum danae

Black Darter – Sympetrum danae

Common Darter - Sympetrum striolatum

Common Darter – Sympetrum striolatum

Four-spotted Chaser - Libellula quadrimaculata

Four-spotted Chaser – Libellula quadrimaculata

Many were also interested in the butterflies, though none were present in large numbers, eleven species were recorded. These included Small Skipper Thymelicus sylvestris, Large Skipper Ochlodes venatus, Large White Pieris brassicae, Green-veined White Pieris napi, Holly Blue Celastrina argiolus, Small Copper Lycaena phlaeas, Peacock Inachis io, Speckled Wood Pararge aegeria, Gatekeeper Pyronia tithonus, Meadow Brown Maniola jurtina and Small Heath Coenonympha pamphilus. In addition a scarce moth was on the target list, Dark Bordered Beauty Epione vespertaria, found at only four sites in the UK, two in Scotland and two in England. I understand that early morning are best for this species, however we did manage to see a single specimen of this attractive moth.

Holly Blue - Celastrina argiolus

Holly Blue – Celastrina argiolus

Small Skipper - Thymelicus sylvestris

Small Skipper – Thymelicus sylvestris

Small Copper - Lycaena phlaeas

Small Copper – Lycaena phlaeas

The supporting cast was provided by several other species groups. Hoverfly Helophilus pendulus was very abundant at this site, with thousands present, and Bog Hoverfly Sericomyia silentis, one of our largest hoverflies was also easily observed here. Bog Bush-crickets Metrioptera brachyptera were present in good numbers, though difficult to photograph, as they rapidly disappeared into the vegetation. Within the same month I find myself  writing about Adders Vipera berus for the third time, at least four individuals seen by various members of the group. In addition several Common Lizards Lacerta vivipara were also seen, though most only briefly as they scuttled for cover.

Bog Bush Cricket - Metrioptera brachyptera

Bog Bush Cricket – Metrioptera brachyptera

Bog Hoverfly - Sericomyia silentis

Bog Hoverfly – Sericomyia silentis

Hoverfly - Helophilus pendulus

Hoverfly – Helophilus pendulus