On the road of dung: hypothetical dispersal routes of dung beetles in the circum–Sicilian volcanic islands

Abstract

We analysed dung beetle communities on ten volcanic islands located around Sicily (Italy) to identify the most probable dispersal routes in the colonization of these islands. Assuming two scenarios, we analysed the dung beetle communities through the coefficient of dispersal direction DD₂. Our results suggest that dispersal fluxes do not strictly follow the ‘stepping stone’ dynamic. Lipari and Vulcano are the likely core source areas for the north–of–Sicily area. In the Sicily Channel, Linosa appears to have been the main target area with three equivalent fluxes from Tunisia, Sicily, and Malta, while the fauna of Pantelleria resulted from their interchange and proximity to Tunisian fauna. In light of the congruence of our results with the known history of human movements and colonization, we propose a likely human contribution to the genesis of the dung beetle fauna of the circum–Sicilian volcanic islands.