Keeping up with the neighbours: using a genetic measurement of dispersal and species distribution modelling to assess the impact of climate change on an Australian arid zone gecko (Gehyra variegata)

Abstract

Aim

During this century rapid climate change will have a profound effect on global biodiversity, and species survival will be contingent on their ability to adapt or disperse. Species distribution models are a popular tool for gauging how the distribution of favourable climate may change over space and time. Evaluating the level of dispersal between the current distribution and potential future distribution of a species is a key to predicting their survival, but rarely estimated. Here we applied species distribution models and a genetic estimate of dispersal to quantitatively assess dispersal to new distributions in the timescale imposed by future climate change.

Location/Methods

We sampled 635 adult Gehyra variegata (2n = 40a/38b) throughout central and eastern Australia, encompassing much of the recorded distribution for this gecko. We genotyped all individuals at 16 microsatellite loci, from which we estimated mean annual dispersal distance using Wright's neighbourhood size. Species distribution modelling predicted the current and future distribution of the species, and we used annual dispersal distances to evaluate whether the species could keep up with shifts in the range of their favourable climatic conditions.

Results

Our estimates of mean dispersal showed that 17–41% of the current G. variegata (2n = 40a/38b) distribution was unlikely to contribute to their future distribution given the timescale imposed by future global climate change.

Main Conclusions

Our approach can make further use of molecular and occurrence record datasets to answer whether a species has the capacity to reach future areas of favourable climate and the extent to which the current distribution will contribute to this process.