Coyote and Prey Interactions in the Piedmont of South Carolina

Vanessa Patch

Abstract

Predator-prey interactions are complex and influenced by various factors, including the temporal activity patterns and space use patterns of each species. Studying overlap between these patterns will therefore further our understanding of the relationships between predators and prey. Coyotes (Canis latrans), a relatively novel top predator in the Southeast, have been shown to be effective white-tailed deer (Odocoileus virginianus) fawn predators in the region. Identifying coyote diel activity patterns and space use patterns in relation to the diel activity patterns and space use patterns of their prey, specifically deer and rabbits (Sylvilagus floridanus), could provide insight into coyote prey selection during fawning season in the Southeast. Our objectives were to quantify coyote, deer, and rabbit diel activity and space use patterns and compare the degree of overlap between these species during fawning season. We hypothesized that predator diel activity is positively related to prey diel activity, and that predator space use is positively related to prey space use. In order to quantify activity, we deployed an array of wildlife cameras across a study area in the Piedmont of South Carolina and used the photo management software digiKam to add metadata to photos. To compare the degree of temporal activity overlap between our focal species, we calculated their overlap coefficients during May 2019. We found that coyote temporal activity was similar to prey temporal activity, with all target species staying active through the night and showing the highest activity during dusk and dawn. We found coyote space use was related to prey space use, with similar overlap between coyote-deer space use and coyote-rabbit space use. An opportunistic hunter, the coyote may be active at night and in similar areas as its target prey to increase the odds that it will come across active deer or rabbits.

Introduction

  • Predator-prey interactions are complex and influenced by numerous factors, including the temporal activity patterns and space use patterns of each species. Studying overlap between these patterns will further our understanding of predator-prey relationships
  • Coyotes (Canis latrans) are a relatively novel top predator in the Southeast and have been shown to be effective white-tailed deer (Odocoileus virginianus) fawn predators in the region
  • Identifying coyote diel activity patterns and space use patterns in relation to the diel activity patterns and space use patterns of deer and rabbits (Sylvilagus floridanus) has the possibility to provide insight into coyote prey selection during fawning season in the Southeast

Materials and Methods

  • Study area: ~15,000 acres of managed loblolly pine (Pinus taeda), hardwoods, and pasture fields in the Piedmont region of South Carolina
  • 93 cameras were set up in an array with approximately 1 sq. km. spacing
    • Camera Settings:
      • Interval: 0.6 seconds
      • Burst: 3 Photos
  • Metadata was manually added to all photos from May 2019 using digiKam photo management software (digiKam Team 2019)
  • Temporal Activity Patterns
    • We used the overlap coefficient (Dhat4 in camtrapR) to determine the degree of temporal overlap between coyotes and their prey
    • Temporal Activity Plots were created using the camtrapR package  (Niedballa et al. 2016) in program R (R Core Team 2020)
  • Space Use Patterns
    • Space use was determined by the percentage of cameras where the target species was photographed
    • Species Richness Plots were created with camtrapR (Niedballa et al. 2016)  in program R (R Core Team 2020)

Conclusions

All three target species showed crepuscular activity patterns, with deer (does) showing more activity during daylight hours. The coyote-deer temporal overlap coefficient (0.86) and the coyote-rabbit temporal overlap coefficient (0.88) show high temporal overlap between both coyotes and deer and coyotes and rabbits.

Coyotes were found at more than twice the number of camera sites in the study area as deer or rabbits; this could indicate that they utilize a larger area or a broader range of habitat types. Locations without deer or rabbits could indicate the presence of other prey species or food sources (i.e fruits; coyotes are omnivores).

Coyotes were detected at most of the camera sites where deer or rabbits were active (94% and 96%, respectively), which could indicate that they actively search for rabbits or fawns in these areas. Although we predicted that coyote space use would overlap more with deer space use than rabbit space use, we found overlap between coyotes and deer and coyotes and rabbits to be nearly equal. This similarity could indicate that rabbits are easier to catch even though fawns are a more substantial meal, or coyotes may spend more time than usual in areas occupied by deer during the month of May due to the availability of fawns as a prey option.

All three species were detected at only 11 (14%) of the 81 camera sites. As an opportunistic hunter, the coyote was active at night and in similar areas as its target prey, perhaps to increase the odds that it will come across active deer or rabbits.

References

RStudio Team (2020). RStudio: Integrated Development for R. RStudio, PBC, Boston, MA URL http://www.rstudio.com/.

Acknowledgements

Thank you to Elizabeth Saldo, Alex Jensen, Mike Muthersbaugh, and Dr. David Jachowski for your mentorship during this unorthodox summer. Thank you to the Clemson University Summer CI & UR Program for offering this opportunity.