Dispersal and connectivity effects at different altitudes in the Euphydryas aurinia complex

Across its European range, the Euphydryas aurinia complex (Annex II of the Habitats Directive) includes a series of distinct populations. At least 3 taxa occur in Italy, each showing slight morphological differences and distinct eco-ethological features. For the first time, we compared metapopulation dynamics of E. (a.) glaciegenita inhabiting a site in the NW Alps (2,100–2,300 m) with E. (a.) provincialis occurring in the Mediterranean biogeographical region in hilly dry grasslands (700 m). To describe patterns of dispersal, we applied the virtual migration model (VMM) to data collected using Mark-Release-Recapture (MRR). We used parameters of survival and migration to explore metapopulation characteristics. In particular we investigated the relative role of connectivity and patch quality in affecting migration rates. We observed differences between the two metapopulation systems, with the “Alpine” population occurring at higher altitude and in more open habitats, showing lower dispersal propensity. In contrast, even though the “Mediterranean” population is more prone to disperse, migration appears to have higher costs. Dispersal abilities affect metapopulation dynamics, which are at the basis of long-term perspectives of survival for butterfly populations. We discuss our results in the framework of conservation and management options for habitats occupied by these Italian taxa of the E. aurinia complex.