Integrating temporal and spatial dimensions of alpine adaptation: Camera-trap insights on bharal (Pseudois nayaur) in Giant Panda National Park

Alpine ungulates exemplify climate vulnerability through their
spatiotemporal adaptation strategies, yet integrated analyses of these
dimensions remain scarce. Here, we investigated how bharal (Pseudois
nayaur) in Giant Panda National Park adjust both time-activity budgets and
spatial distributions under extreme seasonal conditions. We deployed a
network of 50 infrared cameras along altitudinal transects (3,300-4,500 m)
during summer and winter. We extracted the Normalized Difference
Vegetation Index (NDVI) from satellite imagery for each camera site and
calculated the Relative Abundance Index (RAI) to quantify activity
intensity and assess its seasonal variation. Our results revealed two key
adaptations. (i) Temporal compression: Activity intensity in winter was
reduced by 66% compared to summer (RAI: 0.85 ± 0.04 vs. 0.29 ± 0.21; p
< 0.01) and exhibited a weaker diurnal-nocturnal contrast (p
< 0.05). (ii) Spatial contraction: The bharal’s altitudinal range
narrowed by 73% from summer (3,685-4,248 m) to winter (3,859-4,012 m),
accompanied by a significant decrease in NDVI (summer: 0.70 ± 0.14 vs.
Winter: 0.14 ± 0.06; p  <  0.05). These findings reveal a
dual-phase adaptation in bharal: expanding activity and range in
resource-rich summers and contracting both in winter to conserve energy.
By integrating infrared camera data with satellite-derived NDVI, our
approach highlights how alpine ungulates respond to seasonal challenges
and provides a foundation for predicting climate-driven shifts in
high-elevation ecosystems.