Evaluation of multiple behavioral responses of sika deer to human hunting pressures

Several ungulate populations have become overabundant worldwide, resulting in ecological and social effects. Wildlife managers must establish effective population control programs to mitigate these negative influences. Hunting is a significant mortality factor for ungulates, which exhibit sensitive behavioral responses toward hunting activities. Wildlife managers need a comprehensive understanding of the ungulate responses to different hunting pressures across seasons. We developed a conceptual method to evaluate multiple behavioral responses to human hunting pressures and applied this to sika deer (Cervus nippon) in Hokkaido, Japan, during August and November in 2015. We measured flight behavior, spatial avoidance, and temporal activity shift during non-hunting and hunting seasons in 4 regions with different hunting pressures. Although we did not observe a clear difference in flight initiation distance among study areas or seasons, sika deer showed significant spatial avoidance during the hunting season in areas with high hunting pressure. Furthermore, sika deer were more active at night in areas with higher hunting pressures, regardless of the season. Collectively, these results suggest that sika deer responded to hunting pressure by changing diel activity to nocturnal throughout the year and avoiding risky areas (i.e., around hunting roads) during hunting season, rather than by increasing flight distance when they encounter humans. Our method can be used for a more efficient population control program for wildlife managers, as it considers the spatiotemporal variations of flexible ungulate behaviors in response to hunting pressures.