Evolution of personality and locomotory performance traits during a late Pleistocene island colonization in a treefrog

Recent empirical and theoretical studies suggest that personality and locomotory performance traits are crucial components of the dispersal syndromes, and that they can evolve during a dispersal process. Island colonisation is one the best characterized processes in dispersal biogeography, and its implication in the evolution of phenotypic traits has been investigated over a wide range of temporal scales. However, the effect of island colonization on personality and performance traits of natural populations has been little explored, and no studies have addressed these processes in the context of late-Pleistocene range expansions. Here, we investigated the contribution of island colonisations triggered by post-glacial range expansions to intraspecific variation in personality and locomotory performance traits. We compared boldness, exploration, jumping performance, and stickiness abilities, in three equidistant populations of the Tyrrhenian tree frog Hyla sarda, two from the source area and one from the colonised island. Individuals from the colonised population were significantly bolder than individuals from the source area, as they emerged sooner from a shelter (p=0.028), while individuals from the source area showed markedly higher jumping and stickiness performance (both p<0.001). We discuss these results in the context of the major microevolutionary processes at play during range expansion, including selection, spatial sorting, and founder effects. However, irrespective of the processes contributing the most, our results clearly indicate that late Pleistocene climatic changes have had major consequences not just on species range dynamics, but also on the spatial patterns of phenotypic variation within species, including personality and locomotory traits variation.