A cooler week brings a butterfly dip

Transect 20 was carried out on Tuesday 18th August when not only the temperatures plummeted, but so did the butterfly numbers. 
It was only about 20°C and the whole transect took place under solid cloud with quite a breeze in places. 
We’re coming towards the end of the season for the Chalkhill Blues and Silver-spotted Skippers, but we had walked as far as Section 5 before we saw a Common Blue. This was disappointing, given the recent high numbers recorded for this species. 
As previously reported, the second section has been mown and has very little by way of nectar sources, so it wasn’t entirely surprising that here we saw just one butterfly: a Meadow Brown. Meadow Browns were seen in all but one section, albeit in lower numbers than in recent weeks. 
There were comparable numbers of Small Heaths to last week – they seem to fly in more windy conditions while the Meadow Browns prefer to hunker down in the grass. 
We spotted five Clouded Yellows across four sections, including two in Fames Rough where we’ve not seen them before.

Count details:
​119 Meadow Brown
53 Small Heath
9 Chalkhill Blue 
7 Common Blue
5 Clouded Yellow
2 Small White
2 Speckled Wood
1 Silver-spotted Skipper
1 Small Copper

Count total:
199 butterflies
from 9 species.

​If you would like to know more about any of the butterfly species mentioned, visit ​butterfly-conservation.org

This week's butterfly

Small Heath (Coenonympha pamphilus) – pictured at top.

• Despite its delicate appearance, the Small Heath is a tough little butterfly, able to survive in dry, nutrient-poor grasslands where many larger species struggle.
• It often basks with its wings closed, using its cryptic colouring to disappear among grasses when predators approach.
• Its caterpillars feed mainly on fine grasses, and the species benefits from short, open turf where warm conditions allow the adults to thrive.
• When to see them in the UK: Usually May–September, with adults often occurring in two broods, depending on location and weather.

This week's survey by Graham Harris and Liz North submitted to 
​Butterfly Conservation (UKBMS).
​Report by GK, LN & AI. Header photo of Small Heath by Duncan Jennings.