Use of Scat DNA to Estimate Coyote Abundance on a Newly Colonized Barrier Island

Authors

• Sonia M. Hernandez, University of GeorgiaFollow
• Michael J. Yabsley, University of GeorgiaFollow
• Sarah C. Webster, University of GeorgiaFollow
• Elizabeth M. Kierepka, North Carolina State UniversityFollow
• Rochelle R. Beasley, Savannah River Nuclear SolutionsFollow
• Carly L. Landa, University of GeorgiaFollow
• Heather W. Barron, Clinic for the Rehabilitation of WildlifeFollow
• Kelly Sloan, Sanibel-Captiva Conservation FoundationFollow
• Holly Milbrandt, City of Sanibel, Florida, USA
• James C. Beasley, University of GeorgiaFollow

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.

Abstract

Coyotes (Canis latrans) have expanded in mainland eastern North America and are known to have successfully colonized numerous islands. However, there are scarce data on the densities of coyotes in these ecosystems, in which coyotes can have substantive negative impacts. Coyotes first colonized Sanibel Island, a barrier island off the western coast of Florida, USA, in 2011, and their presence has been linked to declines in several sensitive species. However, the population size of coyotes has only been estimated from anecdotal reports and camera traps. Our goal was to estimate the size of the coyote population on Sanibel Island using genetic mark-recapture methods from fecal sampling. We used transect and opportunistic sampling in winter 2015–2016 to collect coyote scats across the main habitat types on Sanibel Island and determine genotypes for each sample. We then used open population POPAN capture-recapture models to estimate coyote population size. We collected 89 scat samples across Sanibel Island. Based on genotypes, these samples came from at least 25 different individual coyotes, with an estimated population size of 39 individuals (95% CI = 30–67) based on our mark-recapture models. These results suggest the coyote population on Sanibel Island rapidly expanded throughout this island since presumed initial colonization in 2011 and that there are more than twice as many coyotes than previously estimated through observational and camera trap data. Further work should focus on better understanding coyote status, habitat use, and ecological impacts. Ultimately, understanding abundance and distribution of coyotes and other invasive species contributes toward developing appropriate management strategies to mitigate impacts to sensitive barrier island ecosystems.

Recommended Citation

Hernandez, Sonia M.; Yabsley, Michael J.; Webster, Sarah C.; Kierepka, Elizabeth M.; Beasley, Rochelle R.; Landa, Carly L.; Barron, Heather W.; Sloan, Kelly; Milbrandt, Holly; and Beasley, James C. (2025) "Use of Scat DNA to Estimate Coyote Abundance on a Newly Colonized Barrier Island," Human–Wildlife Interactions: Vol. 19: Iss. 1, Article 8.
DOI: https://doi.org/10.26077/654k-fr35
Available at: https://digitalcommons.usu.edu/hwi/vol19/iss1/8