Dispersal response to climate change: scaling down to intraspecific variation

International audience; Range shift, a widespread response to climate change, will depend on species abilities to withstand warmer climates. However, these abilities may vary within species and such intraspecific variation can strongly impact species responses to climate change. Facing warmer climates, individuals should disperse according to their thermal optimum with consequences for species range shifts. Here we studied individual dispersal of a reptile in response to climate warming and preferred temperature using a semi-natural warming experiment. Individuals with low preferred temperatures dispersed more from warmer semi-natural habitats while individuals with higher preferred temperatures dispersed more from cooler habitats. These dispersal decisions partly matched phenotype-dependent survival rates in the different thermal habitats, suggesting adaptive dispersal. This process should result into a spatial segregation of thermal phenotypes along species moving ranges which should facilitate local adaptation to warming climates. We therefore call for range-shift models including intraspecific variation in thermal phenotype and dispersal decision.