Vanessa atalanta (previously also known as Pyrameis atalanta). Devon, UK.
The Red Admiral is a well-known colourful butterfly, found in temperate Europe, Asia and North America. The species is resident only in warmer areas, but migrates north in spring, and sometimes again in autumn.
This species occurs in Britain as a migrant originating from northern Africa and southern Europe, and being an extremely mobile species, can turn up in any habitat including woodlands, grasslands, meadows, heathlands and moors, coastal habitats, riverbanks, low montane habitats, gardens, parks, allotments and town centres. Males also gather at certain grassland hilltop sites, apparently to intercept migrating females. The number of migrants varies according to variations in climate in Europe, and this greatly affects the number of UK bred butterflies seen later in the year.
Migrants arriving in the early spring oviposit on stinging nettles growing along hedgerows or in woodland glades, producing a summer brood in the UK which typically emerges from mid July to early August. In late summer these butterflies migrate south, and there is some evidence that the butterflies attempt to overwinter in southern woodlands.
On sunny days the butterflies often bask on tree-trunks, always assuming a head-downwards or sideways facing position. In warm but overcast weather they like to bask on the foliage of bramble, hazel and other bushes. Favoured summer nectar sources include hemp agrimony, bramble, marjoram and ivy blossom. In gardens they will attend buddleia, ice-plant, and michaelmas daisies. In orchards they will feed at fallen apples or pears. They will also imbibe mineral salts from damp ground, and will visit sap runs on oak trunks. The bark-like underside of the wings provides excellent camouflage for the butterflies when they roost at night and on dull days, head downwards, on the trunks or lower branches of oaks, larch and other trees.