Wet creatures in a warming world: How climate change will impact the future distribution of anuran amphibians from Brazilian semiarid region?

Abstract

The world has been going through a climate crisis that has led to a substantial increase in global temperatures. Consequently, amphibians, ectothermic animals that depend on water to survive/reproduce, are under increasing threat. In this research, we compared the influence of climate change on the geographic distribution between anuran species with occurrence restricted to the Brazilian semi-arid region (Caatinga domain) and widely distributed congeneric species, with occurrence in multiple biomes. We hypothesized that climate change would be more harmful for species of restricted distribution than for those widely distributed. For this purpose, using ecological niche modeling, we designed potential distribution models for current and four future climate scenarios, and compared two metrics (climatic suitability and index of extent of occurrence) between restricted and widely distributed species. The results revealed that the climatic suitability did not differ among current climatic conditions and those expected for 2050 and 2090, nor differed between species with distribution restricted to the Caatinga and widely distributed ones. On the other hand, contrary to our predictions, while species with wide distributions would tend to retract their extent of occurrence in future times, species with restricted distributions would expand their ranges. These results suggest that species with current distribution restricted to Caatinga biome might be relatively favored by the climate changes predicted for the next 80 years. However, we discuss that this result should be interpreted with very caution, because many ecological and conservation requirements need to be guaranteed so that these predictions can actually occur. Our findings contributed to the understanding of the effects of climate change on closely related taxa, with different distribution patterns, revealing particularities of the anuran amphibians that occur in semi-arid environments in response to climate changes predicted for this century.