Spatiotemporal partitioning and species associations among multitrophic wildlife in the Jiacha Valley of the Yarlung Zangbo River

Understanding how wildlife species differ in their use of time and space in human-influenced, high-altitude landscapes is important for interpreting multispecies associations and informing conservation. The Jiacha Valley of the Yarlung Zangbo River, located in a biodiversity hotspot on the northeastern edge of the Himalayas, provides important refugia for wildlife in an unprotected high-altitude ecosystem. Across 80 functioning camera stations, we accumulated 46,489 camera-trap days and recorded 23,702 independent wildlife detection events from May 2020 to November 2023. For site-use modeling, warm-season records from 2022 were divided into 18 consecutive 10-day sampling occasions. Using kernel density estimation and single-species and conditional two-species site-use models, we quantified diel activity overlap, site-use patterns, and pairwise spatial associations among five focal species representing different ecological roles: snow leopard ( Panthera uncia ), dhole ( Cuon alpinus ), brown bear ( Ursus arctos ), Himalayan serow ( Capricornis thar ), and Xizang eared pheasant ( Crossoptilon harmani ). Diel activity overlap ranged from Δ = 0.208 for P. uncia – C. alpinus (95% bootstrap CI 0.121–0.301) to Δ = 0.683 for P. uncia – C. thar (95% bootstrap CI 0.554–0.798). Site-use probability of C. thar increased with vegetation greenness ( β = 1.26, P = 0.018) and decreased with elevation ( β = −1.01, P = 0.017), whereas that of C. harmani increased with elevation ( β = 1.29, P = 0.012) and decreased with distance to roads (β = −0.65, P = 0.032). Site use of U. arctos increased with aspect ( β = 3.01, P = 0.018), although this estimate was based on sparse detections. SIF estimates ranged from 0.314 to 2.772, and the 95% confidence intervals included 1 for nine of the ten species pairs. The SIF estimate for U. arctos – C. harmani was 1.456 (95% CI 0.833–2.331). Overall, these results reveal species-specific differences in temporal activity and site use and are consistent with temporal or spatial differentiation among some species pairs, but they do not by themselves demonstrate a mechanism maintaining species coexistence. They provide baseline information for wildlife conservation in this unprotected high-altitude landscape.