Meadow Browns dominate in the summer heat

Friday 7th August was chosen for Transect 19. It was another very warm one, under a virtually cloudless sky. After many weeks of heat and drought, all of the fields on our transect route are parched brown. Yet despite there being fewer flowers, the number of butterflies is at an all-time high for this time of the year.
This is due entirely to the super abundance of Meadow Browns, who have more than doubled their average count. The Common Blues, Chalkhill Blues and Small Heaths are also having a good year. 
Clouded Yellows are infrequent visitors but this is the third transect in succession when we’ve seen them in higher numbers than previously (Liz even spotted a rare ‘helice’ form, a paler variant of female CYs, see below).
A remarkable find and another reminder that even in our drought-stricken landscape, the butterfly season can still produce some unusual surprises.

Count details:
​ 481 Meadow Brown
104 Common Blue
65 Small Heath
35 Chalkhill Blue
18 Small White
15 Clouded Yellow
9 Small Copper
5 Large White
3 Silver-spotted Skipper
3 Speckled Wood
2 Gatekeeper
2 Painted Lady
1 Brown Argus
1 Brown Hairstreak
Count Summary:
744 butterflies from 14 species.
If you would like to know more about any of the butterfly species mentioned, visit ​butterfly-conservation.org

An unexpected rarity

Clouded Yellow (Helice) - Liz North

Clouded Yellow (Colias croceus)

• A powerful long-distance migrant, the Clouded Yellow regularly crosses the English Channel from continental Europe, sometimes arriving in Britain in spectacular numbers after favourable winds.
• The rare ‘helice’ form shown here is a pale, creamy-white female rather than the usual yellow-orange colour. She can look remarkably like a Large White at first glance, but the distinctive wing markings reveal her true identity.
• Clouded Yellows are restless, fast flyers, often travelling low and rapidly across open grassland, making them notoriously difficult to follow or photograph.
• When to see them in the UK: Usually June-October, with numbers typically peaking in August and September. Some years produce very few sightings, while favourable migration years can bring large influxes.

This week's survey by Graham Harris, Liz North and Brian Gardner submitted to 
​Butterfly Conservation (UKBMS).
​Report by GK, BG & AI. Header photo of Brown Hairstreak by Liz North. ​