IMPACTS OF RINGTAIL (Bassariscus astutus) RELOCATION AND DIETARY SUBSIDIES IN GRAND CANYON NATIONAL PARK

Hoffman, Blake

The scope of this thesis encompasses research aimed to advance our understanding of ringtail (Bassariscus astutus) ecology on human-altered landscapes with an emphasis on the impacts of managing nuisance ringtails in an urbanized setting. Our work centered around Grand Canyon, Arizona, a small municipality within Grand Canyon National Park, and was designed to address a diverse set of research objectives. Findings from this work have been consolidated into two manuscript chapters describing the outcomes of nuisance ringtail relocation and diets of urbanized individuals compared to those in natural settings. Among ringtails relocated during the course of this study, 55% successfully navigated back to their original capture sites from distances up to 25 km; nearly 4x further than previously documented. Relocation largely failed to humanely mitigate issues related to nuisance ringtails with only 1 of 11 individuals confirmed to have established a new home range in a natural setting. Concurrently, we used a multifaceted approach to investigate diet and found that anthropogenic food subsidies appeared to augment ringtail diet without much effect on natural dietary behavior. Stables isotope analysis showed significantly higher d15N in the tissues of urbanized ringtails than those occupying more natural settings, indicating greater protein consumption. When comparing the fecal contents of these two groups, both displayed similar occurrence of natural food items in their scats, but nuisance ringtails disparately possessed high frequencies of anthropogenic materials (e.g. plastics) in their feces (73%). This difference would suggest that anthropogenic subsidies provide ringtails with additional protein but may not diminish their capacity to reduce prey disease-vectors.