Abstracts

Abstract: Coyotes (Canis latrans) are now well-established in South Carolina and directly impact white-tailed deer populations mainly through fawn predation. Researchers have found deer increase vigilance in response to increasing coyote predation risk and does with fawns seek temporal refugia. However, few studies simultaneously examine potential antipredator responses including shifts in space-use, diel activity, and vigilance behavior. We used passive camera traps during summer 2019-2021 to quantify the impacts of biological and environmental factors on deer spatial activity patterns, diel activity patterns, and vigilance behavior. We hypothesized that responses to coyote encounter risk would vary among deer demographics and predicted that the strength of responses would scale with vulnerability. Overall, our results suggest that deer are unable to eliminate the risk of encountering coyotes by modifying their spatial activity. Spatial activity patterns of does without fawns were positively related to daily coyote activity, possibly indicating coyotes key in on areas with does during fawning season, and such does were more vigilant at sites with greater long-term coyote activity. Nursery groups were more diurnal than adult deer without fawns, reducing diel activity overlap between fawns and coyotes. In conclusion, deer respond to coyote encounter risk by altering behaviors on temporal scales or increasing perceptive vigilance behavior. Future research should investigate how habitat and activity of humans and competitor species affect nursery group behaviors, particularly as these factors relate to nursery groups tendency to be active during the day as they attempt to reduce the risk of encountering coyotes.