Ecological Factors at Fine Spatial Scale Associated With Habitat Use by Tigers in Western Terai Arc Landscape, Nepal

Conservation of designated source sites is a fundamental strategy for global tiger recovery. Reliable estimates of tiger Panthera tigris habitat use within these source sites are crucial for informing effective management strategies. In this study, we assessed tiger habitat use within the Bardia-Banke Complex, one of the 42 global source sites, situated in the western Terai Arc Landscape (TAL) of Nepal. We conducted a grid-based detection and non-detection camera trap survey across 719 grid cells, each measuring 2 × 2 km². To assess tiger habitat use while accounting for imperfect detectability, we applied a single-season occupancy model. We analyzed nine covariates that have the potential to influence tiger habitat use in the Complex, including terrain, co-predators, prey, water availability, and disturbance. We found that fine scale (2 × 2 km²) tiger habitat use in the Complex was 0.43 (SE ± 0.0085, 95% CI: 0.414-0.448). Our analysis demonstrated that tigers used habitats unevenly across the Bardia-Banke Complex. Our results showed that the terrain ruggedness index, prey index, and proximity to waterholes were key determinants of tiger habitat use. Tiger habitat use was positively associated with prey abundance and negatively associated with terrain ruggedness and distance to waterholes. We emphasize the importance of influencing habitat covariates that determine the probability of habitat use for taking appropriate habitat-management decisions for tiger conservation in the TAL. We highlight the importance of periodic assessment of tiger habitat use in this globally significant source site to monitor changes in spatial habitat use patterns, serving as a measure of the effectiveness of wildlife management interventions.