Social and Environmental Drivers of Black-Necked Crane (BNC) Habitat Suitability in Bhutan: Insights from Maxent Modelling and Conservation Implications

Species distribution modelling (SDM) constitutes a fundamental tool in the domain of conservation biology, offering valuable insights into the ecological requisites of imperilled species. Within this context, habitat suitability assessment assumes a pivotal role in the strategic planning of wildlife conservation and population management initiatives. This study employs the Maxent-LQH model to conduct a comprehensive estimation of habitat appropriateness for the endangered, black-necked crane (Grus nigricollis) within Bhutan. The primary objective was to improve the understanding of the current habitat status of this avian species by leveraging a dataset comprising 23 occurrence records and 10 environmental variables. A regularization multiplier of 3 is judiciously selected through the application of the Akaike information criterion, considering the small sample size. The investigation revealed that distance to settlements (31.7%), NDVI (20.5%), distance to roads (20.2%), and distance to rivers (17.7%) were the principal environmental determinants that significantly influenced black-necked crane habitat suitability. The secondary variables, encompassing aspect, BIO-19, LULC, slope, BIO-15, and BIO-5, collectively exhibited a cumulative contribution rate of 9.9%, indicating a comparatively modest impact on BNC habitat suitability. This study revealed a spatially confined suitable habitat area for black-necked cranes within Bhutan spanning 549 km², representing 1.443% of the nation's total land area. To validate the robustness of the model, AUC statistics were calculated, revealing a commendable accuracy level of 0.98 and indicating the efficiency of evaluating the suitability of the black-necked crane. These findings underscore the pivotal influence of specific environmental determinants on the distribution of this species within Bhutan. This study advocates the judicious incorporation of these insights into conservation and protection strategies, thereby contributing substantively to preservation endeavors aimed at mitigating the threats faced by the endangered BNC.