The warmth of the late summer sun is sufficient to stir the last of the season’s butterflies on these east coast dune systems. While a single common blue stands out at a distance against the sandy brown vegetation, the better camouflaged graylings – of which there are many – are not evident until they rise from beneath my feet. Each of the graylings flutters away to settle just a few feet ahead. As they lands so each turns its body, angling its now folded wings at 90 degrees to the sun and exposing the wing and the length of the body to the warming rays. In order to remain active a grayling needs to maintain its body temperature at about 32 degrees Celsius, hence the basking behaviour being so evident at this time of the year.
Without exception all of the graylings I encounter look rather tatty, the wing edges notched and broken, and the wing colouring faded through the loss of covering scales. To be fair, this is not a butterfly for those seeking something bright and colourful; it is a butterfly for those who appreciate the way in which it blends into the dry, dusty habitats within which it lives. The grayling is an unobtrusive butterfly, the females particularly secretive and both sexes rarely observed to nectar on late season flowers. I have heard it said that the adult grayling doesn’t feed but this isn’t true; the adults take nectar very early in the morning and again in late afternoon, outside the hours when most watchers are out looking for butterflies.
The species used to be common on the sandy soils of the Brecks but it has become increasingly rare inland and the best of our colonies are to be found on the dunes at Winterton and Holkham. More widely, the grayling has been lost from many former haunts. It once occupied certain chalk downland sites, where the turf was kept very short, or even scraped bare, by rabbits. Myxomatosis did for the rabbits and, by association, the butterflies. The colony at Winterton, the one I am visiting today, seems to have had a good season, with plenty of individuals evident. Let’s hope that its success continues for many more summers.