More time for aliens? Performance shifts lead to increased activity time budgets propelling invasion success

Abstract In the Grinnellian niche concept, realized and potential distribution is characterized as an interplay among fundamental niche, biotic interactions geographic accessibility. Climate one of main drivers for this concept essential to predict a taxon’s distribution. Mechanistic approaches can be useful tools, which use fitness-related aspects like locomotor performance critical thermal limits organism. These mechanistic allow inclusion key ecological processes local adaptation account traits different life-history stages. The African Clawed Frog, Xenopus laevis , highly invasive species occurring on five continents. French population special interest due ongoing expansion 40 years broad base knowledge. We hypothesize that (1) exhibits increased activity time in European range could devoted fitness-relevant (2) tadpoles may have less available than adult frogs from same range. investigate how translate into budgets differences responses stages boost invasion. approach based generalized additive mixed models, where curves were used hours compare two native populations. Our results show more Europe compared South frogs, might advantage searching prey or escaping predators. However, do not populations suggesting suffer strong selective pressure frogs.