Understanding and mitigating coyote predation on black-footed ferrets
Date
2019
Authors
Windell, Rebecca Much, author
Breck, Stewart, advisor
Angeloni, Lisa, committee member
Bailey, Larissa, committee member
Eads, David, committee member
Journal Title
Journal ISSN
Volume Title
Abstract
Coyotes (Canis latrans) kill more livestock than any other mammal in the U.S. and can be important predators of vulnerable native fauna. In prairie ecosystems, coyotes are the primary predator of endangered black-footed ferrets (Mustela nigripes; hereafter, ferret), where coyote predation can significantly hamper ferret recovery efforts. To better understand coyote predation on ferrets we used remote wildlife cameras, occupancy models, and overlap of circadian activity patterns to investigate multiple abiotic, biotic, and temporal factors hypothesized to influence coyote use of prairie dog colonies, and by proxy coyote-ferret interactions. We first assessed coyote preferences between prairie dog colonies and surrounding available grasslands and found coyotes used prairie dog colonies nearly twice as much as surrounding grasslands. Next, we investigated biotic and abiotic factors that may influence coyote use and frequency of use on prairie dog colonies. We found high coyote use across our study area, but frequency of use varied across prairie dog colonies and was higher in areas of high badger occurrence. Badgers and coyotes are known to form hunting associations and high overlap between coyote and badger activity patterns in our study further supported spatial use patterns revealed by our occupancy analysis. Strong interspecific competition and patterns of resource selection between badgers and ferrets have been documented in previous studies, and as a result, our study suggests that coyote attraction to badgers may be the principal influence on coyote-ferret interactions. To mitigate coyote predation on ferrets we excluded coyotes from ferret occupied areas with a new non- lethal tool, coyote fladry (hereafter; fladry), and rigorously assessed fladry's effectiveness for future use in both ecological and agricultural scenarios. Again using wildlife camera data, we evaluated coyote fladry with multi-season occupancy models, where we estimated probabilities of use (i.e., occupancy), avoidance (i.e., extinction), attraction (i.e., colonization), and activity (i.e., detection) in response to fladry. Our results indicate fladry reduced coyote use and activity within protected areas for at least 60 days; however, coyotes also increased activity around, and were attracted to, the periphery of fladry exclosures, suggesting fladry may function in a way that is counterintuitive to management expectations. Occupancy models permit robust evaluation of nonlethal tools beyond binary terms of success and failure and provide valuable additional information, such as the behavioral responses of carnivores to these tools. Coyote fladry does not deter badger use of protected areas, and given the importance of badgers in predicting coyote use of colonies, future efforts to reduce coyote predation on ferrets should compare the effectiveness of tools that exclude both badgers and coyotes to our study's results.