On the southern flank of Watlington Hill on the Chilterns escarpment, a trail runs along a valley side where the great richness of the wild flora is matched when conditions are right by the insect life. The location (SU705934) is sheltered so in windy conditions butterflies funnel in here from the more exposed hilltop and western facing slopes of this National Trust site. And in a plentiful year such as 2015 for second brood chalkland butterflies this can be a place par excellence in which to observe them.
The trail begins from the NT car park at the top of the hill, emerging from woodland just before the steep open slope in the centre of the site plan (above). Around the base of that slope and in other more open areas good numbers of Silver-spotted Skipper and Chalkhill Blue were active. I recorded the first of those species for my British Butterflies series during the awful weather of late July. The battered and bedraggled individual that I posted pictures of on 28th (see here) conveyed the conditions in which it was found. That unfortunate butterfly emerged in a period of strong wind and torrential rain and possibly knew no different in its short life. But SSS are such photogenic little charmers when the sun is shining, and these pictures (below) taken today show how they should be experienced.
I was struck today by the size variation in the hundreds of Common Blue present here. Collins Butterfly Guide says that in both sexes appreciable intra-seasonal differences occur and this demonstrates the ecological adaptability of the species. In the left-hand picture (below) the male Common Blue is smaller than the Brown Argus that has settled next to it. The right-hand specimen was so tiny that I wondered if I was seeing a first ever Small Blue at this site, until it revealed the underwing pattern of Common. The central picture shows a more usual size differential between male and female Common Blue.
Lastly, here is a grasshopper du jour to add to my recent collection. I have now invested in a series of A5 laminated ID plates published by Peregrine Publications. These explain that grasshoppers cannot be identified reliably by colour since this varies tremendously between individuals of the same species. So there’s the explanation why I always have difficulty in matching my own photographs to field guides. I am pretty sure this one (below) is a Field Grasshopper that is widespread and common from July to October in dry short grassland.
I went out this afternoon thinking in terms of filling in time but was given a reminder that something more can always be squeezed out of any butterfly season. This was how things should be: a peaceful site, only manageable numbers of dog walkers and joggers, no traffic noise or light aircraft doing aerobatics overhead, no tourists or in-your-face paparazzi: just spectacular wild flowers supporting a wealth of fascinating wildlife to be enjoyed.