Mapping Conservation Priorities and Assessing Connectivity Pathways for Threatened Mammals Under the Changing Land-use and Climate in the Eastern Himalayan Biodiversity Hotspot of Bhutan

Abstract

High species diversity and endemism within a vast area of intact and unexplored landscapes, makes the Eastern Himalayas a unique global biodiversity hotspot. The region is home to 255 native terrestrial mammal species including 75 globally threatened species such as the iconic tiger Panthera tigris, snow leopard Panthera uncia and the greater one-horned rhinoceros Rhinoceros unicornis. To complement the IUCN Red List of Threatened Species, I assessed the current conservation status of native terrestrial mammal species in the Eastern Himalayas and identified the 50 most threatened species based on conservation status, endemism, range size, and evolutionary distinctiveness. Despite a mismatch between current distribution of protected areas and priority areas to conserve these threatened mammals, my findings on the extent of ecoregion protection suggests adequate remaining natural habitats to expand current Eastern Himalayan protected areas. <br/> Between 2014 and 2015, I deployed 1858 camera traps within 1129 5-km x 5-km grids over 536 days to investigate richness and diversity of mammals between protected areas, biological corridors, and intervening areas (NPAs) along an elevational gradient in Bhutan. My study revealed 18 (32%) of 56 identified mammal species were IUCN-listed threatened species. Bhutan's network of protected area and biological corridors harbor a richer mammal community than NPAs. Vegetation zones at upper and lower elevation ranges had high species richness and diversity relative to mid-elevations which had higher human presence. <br/> Finally, I assessed the ecological functionality, structural design, and management effectiveness of Bhutan's biological corridor network by integrating detailed climatic, ecological, and biological data with emphasis placed on meta-populations of threatened, wide ranging, and umbrella mammal species. To capture areas known to support high diversity of threatened species and reconcile current land use impact and climate change on biodiversity, the top seven priority areas for expansion within this network were identified. My innovative study fills a gap in existing knowledge on current progress and future prospective toward the novel idea by E.O. Wilson of securing a half earth, to conserve biodiversity, address the species-extinction crisis, and prevent collapse of vital ecosystem services such as carbon sequestration and climate regulation. My work is also an important milestone in addressing knowledge gaps for conservation of threatened mammals in the Eastern Himalayas. Regional collaborative cooperation for effective transboundary research and management is necessary, and regional prioritizing of areas for biodiversity conservation is essential to prevent species extinction.