A PRACTICAL MODEL OF METAPOPULATION DYNAMICS

1. This paper describes a novel approach to modelling of metapopulation dynamics. The model is constructed as a generalized incidence function, which describes how the fraction of occupied habitat patches depends on patch areas and isolations. 2. The model may be fitted to presence/absence data from a metapopulation at a dynamic equilibrium between extinctions and colonizations. 3. Using the estimated parameter values, transient dynamics and the equilibrium fraction of occupied patches in any system of habitat patches can be predicted. The significance of particular habitat patches for the long-term persistence of the metapopulation, for example, can also be evaluated. 4. The model is fitted to data from three butterfly metapopulations. The model predicts well the observed minimum patch size for occupancy and the numbers of extinctions and colonizations per year (turnover rate). The results suggest that local populations of the three butterflies in patches of 1 ha, which may support of the order of 1000 adult butterflies, have an expected lifetime of 20-100 years.