Estimates of gene flow between populations of the swallowtail butterfly, Papilio machaon in Broadland, UK and implications for conservation Original Research Article

The swallowtail butterfly, Papilio machaon has a recognised subspecies britannicus which is confined to the Broadland area of Norfolk, UK. The subspecies is threatened by habitat change and fragmentation. Gene flow was studied between four sites in this area using allozyme and RAPD-DNA analysis to see if there is any evidence of isolation of populations or inbreeding that could pose a threat to the species persistence. The allozyme studies suggest high levels of gene flow and a very low value of Neiʹs genetic distance (D) between sites. RAPD analysis also suggested extensive gene flow between sites. The results indicate that there is little or no isolation of populations and that the species is capable of colonising and exploiting suitable habitats within the Broadland area. Consequently a landscape scale rather than site-based conservation strategy is recommended.