, basking on the grassy ramparts of an Iron Age hillfort in Dorset. The caterpillars feed on Bird's-foot Trefoil (Lotus corniculatus)
and Horseshoe Vetch (Hippocrepis comosa)
. Preferred habitat: rough-grazed grassland where the ground has been disturbed by cattle. Once a very common species in the UK.
"Unfortunately, numerous colonies have been lost in recent years, making this one of our most rapidly declining butterflies. The principal cause has been the 'improvement' of most ancient grassland for agriculture, which eliminates the butterfly's foodplants." The Butterflies of Britain & Ireland
- Jeremy Thomas & Richard Lewington.