Forecasting climate-resilient conservation futures for the White-bellied Heron ( Ardea insignis ) in Bhutan using coupled model intercomparison project phase 6 climate scenario

The White-bellied Heron (Ardea insignis), one of the world’s rarest birds, is critically endangered with fewer than 60 individuals globally. Bhutan harbors the largest known population, offering a vital opportunity for species conservation under future climate uncertainty. This study presents Bhutan’s first nationwide, climate-informed habitat suitability model for the White-bellied Heron. Using 361 verified occurrence records from 2001 to 2024 and 24 environmental predictors including topographic, bioclimatic, and anthropogenic variables, we applied a weighted ensemble modeling framework that combines generalized linear models, generalized additive models, and random forest algorithms. Model weights were calibrated to improve predictive accuracy and ecological relevance. The framework supports spatial projections of current and future habitat distributions under Shared Socioeconomic Pathway 3 climate scenarios for the periods 2041 to 2060 and 2061 to 2100. Under baseline conditions (1996 to 2014), 8219 km² of Bhutan is identified as suitable habitat, expanding to 13,784 km² by 2100. However, projections reveal fragmentation and shifting suitability zones, particularly in unprotected districts such as Monggar and Pemagatshel. Protected areas like Royal Manas National Park retain high suitability, while others including Bumdeling Wildlife Sanctuary and Jigme Khesar Strict Nature Reserve may become unsuitable. These results should be interpreted with caution due to limitations in modeling dynamic anthropogenic pressures such as hydropower development, road expansion, and land-use change. The absence of spatial data on infrastructure footprints and fine-scale ecological filters may lead to overestimation of habitat suitability in certain regions. This study identifies protection gaps, proposes Other Effective Area-Based Conservation Measures, and emphasizes the need for connectivity and adaptive strategies. Bhutan’s proactive conservation planning offers a valuable model for climate-resilient biodiversity management.