Abstract: To investigate the variation pattern of alert behavior in Callosciurus erythraeus （red-bellied squirrel） in response to different levels of human disturbance within an urban campus habitat and to analyze its relationship with habitat conditions, four sample plots with varying disturbance intensities were demarcated based on pedestrian traffic flow in a campus habitat from April 2024 to March 2025. The alert distance （AD） and flight initiation distance （FID） of the squirrels were measured through field observation and indoor analysis, and environmental information was also recorded. The results showed significant differences in AD among the different plots, with the AD in the least disturbed plot [（6.97±1.79）m] being significantly greater than that in the other plots （p<0.001）. No significant difference in FID was observed among different disturbance intensities. Within the least disturbed plot, the FID on sunny days was significantly higher than on cloudy days （p=0.005）. Regarding habitat types, areas with low human disturbance, dense tree cover, and concentrated food resources were more frequently utilized by the squirrels. In conclusion, in the urban campus environment, the behavioral response of red-bellied squirrels to human disturbance is primarily manifested in an earlier alert phase, while their flight initiation distance remains relatively stable. Habitats with low disturbance and complex vegetation are more conducive to their activity.

Key words: alert behavior, Callosciurus erythraeus, campus, influencing factor