Movement ecology and habitat preferences of translocated greater one-horned rhinoceros in their historic range in Nepal

The greater one-horned rhinoceros (Rhinoceros unicornis, hereafter, rhinos) has lost much of its historical range and now survives only in a few isolated protected areas in Nepal and India. Listed as ‘Vulnerable’ on the IUCN Red List and in Appendix I of CITES, it remains one of the most threatened megaherbivores. To restore populations within their former range, Nepal has translocated rhinos from Chitwan National Park (NP) to Bardia and Shuklaphanta NP since 1986. In 2016/17, eight individuals were released in the Babai Valley of Bardia NP, five of which were fitted with GPS collars programmed to record hourly locations. Despite these efforts, the habitat use and spatial distribution patterns of translocated rhinos have remained poorly understood, despite being crucial for ecological sustainability. In this study, we analyzed 24,014 GPS fixes to map fine-scale habitats, estimate home ranges, and assess movements and habitat uses. Annual and seasonal home ranges were calculated using the Fixed Kernel (95%) method in Home Range Tools (ArcMap 10.3). Habitat preference was examined by overlaying GPS locations with classified Sentinel-2A imagery (10 m resolution). The average home range of collared individuals was 11.61 km2 , ranging from 15.07 km2 during the dry season to 5.35 km2 in the monsoon season. Average daily movement ranged from 2.71 ± 0.12 km to 4.34 ± 0.30 km. Spatial analyses revealed that grasslands (45.47%) were the most used habitat, followed by riverine forests (21.93%) and water bodies (13.53%), while Shorea robusta (Sal) and mixed forests were the least used (6.97%). These findings provide critical insights into habitat use and movement ecology, highlighting the need for habitat-specific management, seasonal connectivity, and grassland restoration to guide long-term rhino reintroduction programs across their historical range.