Spatial and Elevational Patterns of Golden Snub-Nosed Monkeys and Tibetan macaques in Lushan County, Ya’an, Sichuan, China

Sympatric species may share a landscape while differing in their environmental associations and daily activity. We examined these dimensions in golden snub-nosed monkeys (Rhinopithecus roxellana) and Tibetan macaques (Macaca thibetana) using 110 field-informed analytical units derived from 118 physical camera stations in Lushan County, Sichuan Province, China. Across 35,529 effective camera-days and an analytical-unit elevational range of 1395–2771 m, we recorded 20 independent unit-level camera-detection events of golden snub-nosed monkeys at 12 units and 1681 events of Tibetan macaques at 94 units. Ten golden snub-nosed monkey-positive units also recorded Tibetan macaques, but overall unit-level similarity was low because Tibetan macaque detections were more widespread. After adjustment for camera-days, golden snub-nosed monkey unit-level detection was positively associated with elevation (OR = 2.007, 95% CI = 1.051–3.833), whereas Tibetan macaques showed a negative estimated association with an interval including one (OR = 0.516, 95% CI = 0.256–1.041). Both species were predominantly diurnal and showed substantial diel activity overlap (Δ1 = 0.908, 95% CI = 0.696–0.923). Frequent unit-level co-use and substantial diel overlap therefore coexisted with contrasting estimated elevational associations, indicating that shared detections in one ecological dimension need not imply similar patterns in another.