Keeping common species common: the role of future climate refugee in species conservation

Climate change is one of the most important challenges for biodiversity conservation. Species may respond to changing climates by moving, adapting, and/or adjusting. The move response is the easiest and quickest as it does not imply any evolutionary and/or physiological response. However, moving in space to track changing climate is not an option for species with restricted movement capacities (e.g., many amphibians) or species endemic to islands. Therefore, the impact of climate change on these species is potentially dramatic, even when they are currently widespread and least concern. Planning for the conservation of these species in a global change context requires a proactive approach, with the identification of climatic refugia, i.e., areas climatically suitable for a given species under both current climate and future scenarios. Here, we demonstrated our approach considering the Hyla sarda, an amphibian endemic of the islands of Sardinia and Corsica, currently widespread in its range, and Least Concern according to the IUCN Red List. We calibrated an SDM for the species focusing on Sardinia and projected it into the future, identifying all areas that can act as future climatic refugia. We also evaluated the coverage of the refugia by the existing protected areas. According to our results, Hyla sarda will experience a significant restriction of its distribution range due to projected climate changes, with small and highly fragmented climatic refugia mostly located outside of existing protected areas. Our findings highlight the importance of considering common species in global change studies. All our conservation strategies should be more proactive if we want to conserve common species before they become rare.