Predator activity and scent cues influence white-tailed deer behavior in a multi-predator landscape

When navigating landscapes, prey make decisions that balance their need to acquire high-quality resources with the risk of predation. When risk is heterogeneous across the landscape, prey can alter their habitat use to avoid high-risk patches, or they can employ behavioral modifications, such as shifting their temporal activity, that allow them to continue to use high-risk patches while offsetting risk. Our objective was to discern how white-tailed deer in a predator-rich environment (the Greater Yellowstone Ecosystem [GYE]) and an environment containing only mesopredators (Ohio, USA) respond to predator urine cues and predator activity. We used camera traps to quantify the spatiotemporal activity of deer before, during, and after applying predator-scent cues (control/water, wolf urine, mountain lion urine, and coyote urine). In the GYE, deer decreased diurnal activity in response to all predator-scent cues, and increased nocturnal activity in response to wolf, mountain lion, and control scents. Deer also spatially avoided the physical presence of grizzly bears and temporally aligned their activity patterns with bears as bear detections increased over time. In Ohio, deer did not alter their spatial or temporal activity in response to predator-scent cues, and we found that deer activity was positively associated with coyote activity, thereby suggesting that deer may be naïve to the predator-scent cues in this region. Our study shows that scent cues alone do not alter the spatial activity of deer, but in regions where deer are not naïve to the risk of predation, they may exhibit changes in their temporal activity.