METAPOPULATION DYNAMICS AND CONSERVATION - A SPATIALLY EXPLICIT MODELAPPLIED TO BUTTERFLIES

We analyse in detail the metapopulation structure of three species of butterflies in regions where they are endangered-Melitaea cinxia in Fi nland and Hesperia comma and Plebejus argus in the UK. Metapopulations are assemblages of local populations in which the whole (metapopulati on) may persist even if all the components (local populations) are vul nerable to extinction. Patterns of habitat patch occupancy and local d ensity in the three species support the general predictions of metapop ulation models. We develop a spatially explicit metapopulation model a nd fit it to data on the three species. The model is tested with indep endent data on H. comma and P. argus, for which it predicts the rate a nd pattern of spread into networks of vacant habitat patches following introduction or natural recolonization. The model can be used to asse ss the potential of specific networks of habitat patches to support vi able metapopulations of given species, and it therefore has great pote ntial value for conservation of butterflies and other species which oc cur as systems of interconnected small populations.