An attempt at re‐establishing the swallowtail butterfly at Wicken Fen

Abstract

Abstract. Details of a reintroduction of the swallowtail, Papilio machaon, to Wicken Fen are given. The introduced population expanded at first, but crashed as a result of the 1976 drought. It then failed to recover and is probably now again extinct on the Fen. The changes in the habitat and the status of the butterfly's food plant, Peucedanum palustre, caused by the drying out of the Fen are discussed, and it is concluded that there is no chance of reestablishing the butterfly permanently at Wicken, unless the Fen can be made wetter.