Papilio machaon, Swallowtail

The Old World Swallowtail or Common Yellow Swallowtail is one of the UK's rarest butterflies, only found in the Norfolk Broads. However, it is also found in North America, Asia and Europe. The males of the species perform a behaviour called 'hilltopping', where individuals congregate near summits of hills in alpine meadows and compete for passing females.