Adaptive responses of Siberian crane behavior patterns under grazing activities

<bold>Objective</bold> Habitat loss and degradation caused by human activities have become the main threats to the survival of the Siberian crane（<italic>Grus leucogeranus</italic>），with grazing activities frequently occurring in its migration stopover sites.This study aims to clarify the behavioral expression of Siberian cranes under grazing activities，reveal the threshold and strategies of their behavioral adaptation，and provide a scientific basis for the conservation of Siberian cranes affected by grazing activities. <bold>Method</bold> In October 2023 and April 2024，behavioral observations of Siberian cranes were conducted in the Tumuji Nature Reserve—a key migration stopover site—using the Instantaneous and Scanning Sampling method.A systematic analysis was performed on the behavioral patterns of Siberian cranes in the presence of grazing activities，as well as the behavioral differences and diurnal rhythm responses between adult and juvenile cranes when facing grazing disturbances. <bold>Result</bold> （1）With the increase in herd size，avoidance behavior gradually became dominant in Siberian cranes，and a herd size of 15 individuals was identified as the critical threshold for behavioral strategy shifts.（2）Adult cranes primarily exhibited avoidance behavior，demonstrating stronger risk perception and evasion capabilities，while juvenile cranes had lower foraging efficiency and weaker risk perception，requiring more time for spatial exploration.（3）Adult cranes actively optimized energy utilization to efficiently respond to risks，whereas juvenile cranes displayed passive behaviors and relied on imitation learning with lower efficiency.These differences reflect the differentiated adaptation strategies of different life stages.（4）Siberian cranes adapted to grazing disturbances through two main strategies：energy optimization （increasing resting behavior to save energy）and temporal niche partitioning（staggering core activities from peak grazing periods）. <bold>Conclusion</bold> The response of Siberian crane behavior to grazing activities shows a nonlinear stepwise change，its behavioral strategies demonstrate remarkable gradient adaptability.