Status of endangered large prey predators following civil unrest in a biodiversity hotspot of India.

Abstract

Biodiversity hotspots, often located in regions of armed conflict face severe threats. Manas National Park, at the confluence of Indo-Burma and Himalaya hotspots, suffered two decades of civil unrest (late 1980s to early 2000s), causing habitat destruction and wildlife declines, including local extinction of the greater one-horned rhinoceros and near-extirpation of swamp deer. Using elephant-back line transect distance sampling and camera trap-based spatially explicit capture-recapture in 2022 and 2023, we assessed post-conflict recovery of endangered prey-predator guilds. We recorded high densities of elephant (9.14 (SE 2.16) per km²), wild buffalo (4.47 (SE 1.51) per km²), and tiger (7.91 (SE 1.05) per 100 km²), while gaur, sambar, and barking deer showed stable densities compared to 2015 baselines. Rhinoceros and swamp deer populations grew significantly (17 (SE 3) and 17 (SE 1) % annually), while hog deer and wild pig populations declined sharply. Tiger poulation recovered, with 57 adults, establishing Manas as a source population for the transboundary landscape, while leopard maintained stable densities (4.77 (SE 0.80) per 100 km². Integration of local stakeholders and digital tools like MSTrIPES improved monitoring efficiency. We recommend targeted augmentation programs for declining species, sustained habitat protection, and the use of elephant-back transects for accurate density estimation of ungulates and megaherbivores.