Chalk Hill Blues

I went for a pleasantly warm but intensely humid and mostly overcast walk round Barnack Hills and Holes in the morning. Lots of beautiful flowers including Clustered Bellflower, Harebell, Common Dodder, Squinancywort and a small group of Autumn Gentian. There were plenty of butterflies too: Chalk Hill Blues were the most abundant, but there were also good numbers of Small Heath, Brown Argus and a few Small Copper.

I spent some time with this mating pair of Chalk Hill Blues, sitting in the grass next to them, trying to focus on the gently waving stem of Common Knapweed that they's selected for their nuptials. The male Chalk Hill Blue is paler and, apart from the Large Blue, larger than other blue butterflies seen in Britain and Ireland (see extra). At Barnack, many hundreds may be seen in August, flying just above the vegetation, searching for females. Large numbers of males may also congregate on animal dung and other sources of moisture and minerals. Females are much less conspicuous, being duller in colour, more secretive in their habits, and spending less time than the males in flight. They are confined to calcareous grassland in southern England and have declined in some areas during recent decades.

The sky gradually became darker during the course of my walk, but I made it home before the next thunderstorms arrived, The accompanying torrential rain temporarily flooded our street, though fortunately not to any great depth!