Climate change impact on small mammals from two Neotropical hotspots

Current climate change represents the unprecedented change in weather patterns across global and regional scales over a short period due to human activity. It is expected to drive changes in species distributions across the globe. Our goal here was to analyse (i) how climate change can impact the future distribution of species in two Neotropical hotspots, and (ii) how future distribution can impact the threatened status of species. We used ecological niche modelling to estimate suitable areas in the present and four future climate change scenarios (SSPs) for 40 species of nonvolant small mammals endemic to the Atlantic Forest and Cerrado biomes of South America. We also inferred species’ future threat levels according to the IUCN’s A3 criteria using future relative area estimates. We found that species will gradually lose more area in all future scenarios, from the most optimistic Shared Socio-economic Pathway (SSP1-2.6) to the most pessimistic (SSP5-8.5) scenario. Species endemic to the Cerrado will see a greater area reduction than species endemic to the Atlantic Forest. Consequently, the Cerrado will have more threatened species than the Atlantic Forest. Species that occupy both biomes will lose proportionally less area than those endemic to the Cerrado but more area than those endemic to the Atlantic Forest. In conclusion, small mammal species will, in general, be negatively impacted by climate change. However, the degree of impact depends on the trajectory of greenhouse gas concentrations and where the species live.