Humans and ecological disturbance create a temporal human shield for prey

Heather Abernathy, Fish and Wildlife, Virginia Tech, Blacksburg, VA, Heather Abernathy, Daniel A. Crawford and Michael Cherry, Caesar Kleberg Wildlife Research Institute, Texas A&M University - Kingsville, Kingsville, TX, Richard Chandler, Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, Elina Garrison, Florida Fish and Wildlife Conservation Comission, L. Mike Conner, Wildlife Research, The Jones Center at Ichauway, Newton, GA, Karl V. Miller, Warnell School of Forestry & Natural Resources, University of Georgia, Athens, GA

Background/Question/Methods
Rapid expansion of human activity alters animal movement and behavior, but how this activity influences species interactions in wildlands remains elusive. With an increase in outdoor recreation contributing to unprecedented visitation rates, there is a need for a deeper understanding of how humans influence species interactions, particularly predator-prey interactions as they may influence ecosystem function. Using data from 180 trail cameras, we investigated the influence of hiking, hunting activity, and off-road vehicle use on the spatiotemporal predator-prey interactions of the endangered Florida panther (Puma concolor coryi), and its main prey, white-tailed deer (Odocoileus virginianus), across ecological disturbance-prone contiguous wildlands using temporal activity analyses and spatial co-occurrence modeling.
Results/Conclusions
We found Florida panthers and humans overlapped spatially as both avoided flooded areas. However, temporally, panthers increased nocturnality in areas with high human activity likely in attempts to minimize encounters with humans. Temporally, deer were more diurnal in high human use areas; as a result, deer significantly reduced temporal overlap with panthers – suggesting that humans created a temporal human shield which may have reduced panther predation risk for deer. Spatially, deer utilized flooded areas, possibly to reduce predation risk during a time of the year when human activity was very low due to extreme flooding, rainfall, and heat (i.e., a time of year when deer cannot employ the temporal human shield). Our results suggest that prey utilize a temporal human shield to reduce temporal predation risk when ecological conditions allow for it and switch to spatial predator avoidance when human activity is low (i.e., cannot employ the human shield). More broadly, our findings suggest ecological disturbance can mediate the effect of humans on predator-prey interactions, which may be impactful enough to affect population- and community-level dynamics.