Landscape effects on dispersal‐related traits in a sedentary butterfly in agricultural landscapes

Agricultural intensification causes the loss and fragmentation of natural habitats, which negatively impacts farmland biodiversity. The concomitant isolation of essential resources may favour increased dispersal ability in flying insects, resulting in differences in flight morphology and dispersal propensity across landscapes. We collected the butterfly Coenonympha pamphilus in four replicated landscape pairs, each consisting of (a) a highly fragmented and intensified ‘modern’ and (b) a less fragmented ‘traditional’ agricultural landscape. We compared condition (i.e. storage reserves), flight morphology, dispersal capacity and propensity of the collected butterflies between both landscape types. We also tested for the impact of landscape composition and configuration at different spatial scales on butterfly traits. No differences between landscape types per se could be found, but a variety of landscape features affected butterfly traits, indicating complex interactions between landscape heterogeneity and dispersal. In particular, landscapes with a high proportion of crop fields appeared to be selected for phenotypes enhancing dispersal ability. Since dispersal is a key factor for the persistence of metapopulations in fragmented landscapes, we argue that limitations on dispersal in relation to compositional and configurational landscape heterogeneity should be considered in the debate on insect declines in agricultural landscapes.