This is the largest of our Browns, although there is some size overlap between these and female Meadow Brown. In flight, it has been described as appearing “buoyant”, with the pale upperwing markings visible. This usually allows an observer to correctly distinguish between this species and Meadow Brown.
This butterfly always rests with its wings closed, so typically only the underwing is visible. However, during courtship, the male will flick his wings open and shut, or briefly hold them open, so a lucky photographer may obtain an upperwing photograph.
Upon settling, the underside of the forewing is often visible, showing the distinct eyespot on an orange background. If disturbed however, the forewings are tucked inside the hindwings; these show a mottled pattern of whites, greys, and browns, and provide excellent camouflage against the bare substrates on which the butterfly prefers to settle. Grayling also has the habit of leaning over when settled, although it is still unclear whether this is done to minimise its shadow or for the purpose of thermoregulation. On particularly hot days it will often stand on ‘tiptoes’.
It is sometimes stated that Grayling rarely feeds; this is not the case however, and it has been observed nectaring on Buddleia, Bramble (Rubus fruticosus), Crown Vetch (Securigera varia), Red Valerian (Centranthus ruber), and Wild Marjoram (Origanum vulgare).