Spatial Dynamics of a Patchily Distributed Butterfly Species

Nine metapopulations of the butterfly Plebejus argus were mapped in North Wales in 1983 and 1990. The metapopulations occured in three biotopes; five were in heathland, one in mossland and three in limestone grassland. Within metapopulations, local distributions of the butterfly corresponded to the spatial distributions of suitable habitat : P. argus was able to colonize virtually all suitable habitat patches that were less than 1 km from existing, populated patches. In contrast, the regional distribution was constrained by the inability of the butterfly to colonize suitable habitat that was further than a fex kilometres from existing metapopulation; some of these sites are now populated by P.argus following successful introductions