[Objectives] Sex ratio, flocking behavior, and activity pattern are crucial components of animal behavior ecology. Such studies of the widespread species are of great significance for exploring the survival adaptation strategy and conducting comprehensive conservation management. This study for the first time investigated the annual flocking pattern, sex ratio, and spatiotemporal activity of wild Common Pheasants (Phasianus colchicus) by means of infrared camera technology. [Methods] From July 2019 to April 2021, a total of 227 independent valid photos were collected from 40 infrared cameras arranged at Tianjin Panshan Scenic Spot for 14 615 monitoring days (Fig. 1). Flocking patterns were analyzed by the chi-square test, while the daily activity rhythm was modeled by the kernel density method. All statistical analyses were conducted by means of SPSS 26.0 and R 4.0.2. [Results] There were 7 flocking patterns of wild Common Pheasants (Fig. 2), in which both single-male and single-female patterns were the most (χ2 = 957.203, df = 5, P < 0.001, Fig. 3). The activity intensity was higher in summer and autumn and low in winter. The relative activity intensity showed seasonal differences between spring and summer (Z = 3.185, P = 0.001), between summer and winter (Z = 3.229, P = 0.001), and between autumn and winter (Z = 2.492, P < 0.050, Fig. 4). The overall data revealed two activity peaks (8:00 ~ 11:00 and 17:00 ~ 19:00, Fig. 5), and the daily activity rhythm showed differences between spring and autumn (Δ= 0.729, P < 0.050), between spring and winter (Δ= 0.614, P < 0.010), and between summer and winter (Δ= 0.717, P = 0.050, Fig. 6). There was no significant sex difference in the activity rhythm of Common Pheasants (Δ= 0.908, P = 0.561, Fig. 7). The temperature range when Common Pheasants had relatively activity intensity was 21 ~ 30 ℃ (Fig. 8). The activity in spring and summer tended to be concentrated in higher elevations (400 to 599 m), while that in autumn and winter tended to be concentrated in lower elevations (200 to 399 m, Fig. 9). There were seasonal differences in relative activity intensity between spring and summer (U = 6.000, Z = 2.146, P < 0.050) as well as between summer and autumn (U = 4.500, Z = 2.166, P < 0.050) in 400 ~ 599 m (Tables 1 ~ 4). [Conclusion] This study reveals the sex ratio, flocking patterns, and flexible spatiotemporal activity patterns of Wild Common Pheasants across seasons. Our findings provide a reference for scientific protection and comprehensive management of this widespread species.