Niche models inform the effects of climate change on the endangered Nilgiri Tahr (Nilgiritragus hylocrius) populations in the southern Western Ghats, India

Large mammals are declining globally due to habitat loss and fragmentation. Climate change is one of the factors known to alter the range of several mammalian species. An early understanding of the effect of climate change on species distributions can provide critical information for conservation planning. Nilgiritragus hylocrius (Nilgiri Tahr) is an endangered ungulate that is restricted to the montane grasslands of the Western Ghats, India. Currently, the Nilgiri Tahr is restricted to a fraction of its former range and is also prone to risks due to several ongoing anthropogenic pressures. However, the impact of global climate change on this emblematic species has seldom been estimated. The goal of our study was to use ecological niche models to quantify the effect of climate change on the habitats of Nilgiri Tahr. Using the maximum entropy (MaxEnt) algorithm, we modelled the potential distribution of Nilgiri Tahr in its native range. The models were developed under the current climatic conditions and then projected onto two future climate change scenarios (RCP4.5 and RCP8.5) and for three different time frames in the future (years 2030, 2050 and 2080). We identified that most of the climatically suitable habitats of Nilgiri Tahr would become unsuitable when global warming intensifies. Our models predicted a complete loss of suitable habitats in many existing protected areas in the Western Ghats. We use insights provided by our modeling results to propose conservation management plans to increase the likelihood of persistence of Nilgiri Tahr in the Western Ghats.