METAPOPULATION DYNAMICS AND CONSERVATION - A SPATIALLY EXPLICIT MODEL APPLIED TO BUTTERFLIES

We analyse in detail the metapopulation structure of three species of butterflies in regions where they are endangered-Melitaea cinxia in Finland and Hesperia comma and Plebejus argus in the UK. Metapopulations are assemblages of local populations in which the whole (metapopulation) may persist even if all the components (local populations) are vulnerable to extinction. Patterns of habitat patch occupancy and local density in the three species support the general predictions of metapopulation models. We develop a spatially explicit metapopulation model and fit it to data on the three species. The model is tested with independent data on H. comma and P. argus, for which it predicts the rate and pattern of spread into networks of vacant habitat patches following introduction or natural recolonization. The model can be used to assess the potential of specific networks of habitat patches to support viable metapopulations of given species, and it therefore has great potential value for conservation of butterflies and other species which occur as systems of interconnected small populations.