Ontogenetic shifts in space use inform pre-release training strategies for giant panda reintroduction

Abstract

Space use dynamics provide critical insights into behavioral adaptations during animal reintroduction programs, yet quantitative frameworks linking ontogenetic habitat selection to training efficacy remain scarce. We analyzed 10-year behavioral observation datasets (remote video observation data and audio interpretation data, n=15 cubs) and GPS tracking data (n=6 cubs) from a maternal-led pre-release training program in the Wolong area of Giant Panda National Park to quantify developmental trajectories of space utilization. We assessed the space use of giant panda cubs undergoing pre-release training using utilization rate of environmental elements (EUR), home range size (HRS), and spatial utilization rate (SUR). The findings indicated that during the course of their pre-release training, giant panda cubs primarily utilized environmental elements such as the ground, trees, and bamboo with behavior developmental processes. As they aged, the proportion of time using these environmental factors changed. Cubs used mostly the ground during early lactation (1-5 months; EUR = 87.65 ± 12.22%) and Trees from 6-14 months (during which canopy use increased by 68.81 ± 23.80%). Cubs underwent terrestrial readaptation approaching independence (15+ months), when they engaged in activities like walking, resting, and drinking water, and eating bamboo provided by humans, but still spent most of the time in the trees (EUR = 65.28%±17.45%). In the second phase (15-27 months), trained cubs occupied 11.43±9.20 hm² of their total home range size (HRS) with 81.80±19.47% spatial coverage efficiency (SUR). These monthly fluctuations in spatial utilization showed limited seasonal differences that may be related to bamboo phenology. Notably, in contrast to conventional assumptions, maternal presence did not significantly affect HRS (F = 0.96, P = 0.331) or SUR (F = 0.47, P = 0.495); given the small sample size (n=6), this non-significant result should not be interpreted as evidence for autonomous spatial competency acquisition by the cubs. These results provide evidence for an ontogenetic shift framework whereby vertical habitat stratification relates to captive-to-wild transition success. Our findings optimize pre-release protocols by identifying critical developmental windows for arboreal competency training and elevation acclimatization, and development of a foraging strategy.