Adaptive management and planning for the conservation of four threatened large Asian mammals in a changing climate

Abstract

Mammals can serve as an indicator of global climate change impacts on species’ distributions due to the wide range of ecological niches they utilize. Tropical Asia encompasses several biodiversity hotspots, is the largest reservoir of mammalian diversity on earth, and has already experienced the extinction of several mammal species either regionally or locally. Global climate change could become a significant driver of species extinction, either directly or synergistically with other factors, such as habitat loss, agricultural expansion, overexploitation, and land use change. Despite the variability of climatic regimes across tropical Asia, the potential impacts of climate change on continental-scale distributions of mammals have not been examined. To address this issue, we developed habitat suitability models for four threatened large mammals (Ursus thibetanus, Elephas maximus, Hoolock hoolock, and Panthera tigris tigris), across their entire distributions in Asia. We used presence-only distribution records and nine bioclimatic and environmental variables and built species-specific habitat suitability models using a maximum entropy algorithm (MaxEnt). We used a moderate and an extreme climate scenario (RCP6.0 and RCP8.5) and three time steps: current, 2050, and 2070. Our results suggest that changes in annual precipitation, annual mean temperature, precipitation, and temperature seasonality could reduce suitable habitat for these mammals and therefore increase their extinction risks. However, several patches of stable habitat are projected to persist through the late twenty-first century, and these climate change refugia areas can be managed as an important strategy for conservation of the mammal species and the maintenance of biodiversity in the face of ongoing climate change. In this context, we recommend the following steps for the conservation of global mammal populations: (i) define the spatial extent (local, regional, or continental scale) of the target mammals, (ii) identify and prioritize climate change refugial areas following ecological niche models or other methods based on biological data, and (iii) implement management actions by analyzing current management tools and the strategies required (e.g., habitat restoration or assisted migration for prioritized species) to achieve long-term conservation goals.