Modelling habitat suitability of western tragopan (Tragopan melanocephalus) a range-restricted vulnerable bird species of the Himalayan region, in response to climate change

Climate change is expected to alter the structure and functions of an ecosystem including species composition and its geographical distribution. There is limited understanding on how the habitat of the Himalayan range-restricted species would be affected under the influence of climate change. In the present study, we model the climate change impacts on habitat suitability of western tragopan (Tragopan melanocephalus), a range-restricted and vulnerable bird species in the Indian western Himalayas. The climate change scenarios of IPCC represented by representative concentration pathways (RCPs) viz. RCP 4.5, RCP 6.0, and RCP 8.5 were considered for assessing the habitat suitability for the year 2050 and 2070. Most influencial variables that may be linked to habitat suitability of Tragopan, such as bioclimatic variables, land use (forest cover and forest type), soil characteristics, and topographic variables (elevation, slope, aspect, heat load index) were considered to develop a model using the Maximum Entropy (MaxEnt) algorithm. MaxEnt is a widely used and accepted tool for modeling species distribution. The model's performance for mapping habitat was evaluated by the Area Under Curve (AUC) (AUC > 90%). The measured TSS value 0.98 and Kappa value 0.71 were elaborated for the aptness of the model for suitable habitat mapping. It was observed that the suitable habitat of the western tragopan would shift towards higher elevations under all RCPs. The study would benefit to biodiversity conservators and policymaker for formulating future strategy and planning for conservation and management of the Himalayan range-restricted bird species. The approach of this study could be replicated with other range-restricted Himalayan bird species for future projections of suitable habitat.