Host plant density and patch isolation drive occupancy and abundance at a butterfly's northern range margin.

摘要: Marginal populations are usually small, fragmented, and vulnerable to extinction, which makes them particularly interesting from a conservation point of view. They also the starting range shifts that result climate change, through process involving colonization newly suitable sites at cool margin species distributions. Hence, understanding processes drive demography distribution high-latitude is essential forecast response global changes. We investigated relative importance solar irradiance (as proxy for microclimate), habitat quality, connectivity on occupancy, abundance, population stability northern Oberthur's grizzled skipper butterfly Pyrgus armoricanus. For this purpose, abundance was surveyed in network consisting 50 patches over 12 years. found occupancy (average variability) were mostly influenced by density host plants spatial isolation patches, while grazing frequency had only an effect patch occupancy. Knowing extends further north, we hypothesize actual variable limiting P. armoricanus might be its dispersal capacity prevents it reaching more patches. The persistence metapopulation face changes will thus fundamentally linked maintenance efficient habitats.