COMPLEXITY OF SPECIES CONSERVATION IN MANAGED HABITATS - INTERACTION BETWEEN MACULINEA BUTTERFLIES AND THEIR ANT HOSTS

Europe's five species of Maculinea butterfly are examples of endangered species adapted to live in traditional, cultural landscapes. All are threatened with extinction in Western Europe because of recent changes in land use. This is illustrated by an historical account of the extinction of the British Maculinea arion populations, despite many conservation attempts. It is shown how the failures proved to be due to ignorance of the key factor for M. arion, its specialization on a single ant host, Myrmica sabuleti. A brief account is given of research that shows how each of the five species is similarly dependent upon a separate host Myrmica ant species and how each has an interesting and rare specific parasitoid. Steps for the practical conservation of existing Maculinea populations including the obligation, under the Bern Convention, to re-establish nationally extinct species are outlined. The procedure and problems involved in re-establishment are illustrated with reference to the successful programme for M. arion in Britain. The best way of ensuring robust populations of Maculinea butterflies is to manage habitats to optimize the density and distribution of the required species of Myrmica host and, secondarily, the distribution of the larval food plant. The value of single species conservation in cultural habitats is discussed. It is concluded that this is possible to achieve and that other rare organisms also often benefit, but only when conservation measures are based on the results of detailed autecological research.