Swallowtail

• Latin name: Papilio machaon
• Family group: Swallowtails
• Countries: England, Scotland, Wales, Ireland
• Size: Large

Resident

Range stable.

This is one of our rarest and most spectacular butterflies. The British race britannicus is a specialist of wet fenland and is currently restricted to the Norfolk Broads. Here the adults can be seen flying powerfully over open fen vegetation, stopping to feed on flowers such as thistles and Ragged-Robin.

The butterfly probably declined within its range during the twentieth century but has benefited over the last few decades from conservation management aimed at increasing open fen vegetation. There are also scattered records of migrants of the continental race.

Conservation status

• UK BAP status: Not listed
• Butterfly Conservation priority: medium
• European threat status: not threatened
• Protected in Great Britain for sale only

European/world range

The race britannicus occurs only in Britain. The continental race gorganus is widespread in Europe, and across Asia to Japan as well as in North America. It has declined recently in some European countries.

Foodplants

The native British race feeds solely on Milk-parsley (Peucedanum palustre). Occasional migrants of the continental race gorganus use a variety of umbellifers such as Wild Carrot (Daucus carota) and Wild Angelica (Angelica sylvestris).

Habitat

The British race britannicus breeds only in open fens and marshes that support vigorous growths of Milk-parsley. The butterfly prefers areas of mixed fen usually dominated by sedge, or sometimes reed, which are cut periodically and contain tall, prominent foodplants. The occasional migrants of gorganus can be found in almost any habitat but are most frequently seen on grassland near the south coast of England.