Publication Date
2021
Document Type
Thesis
Committee Members
Volker Bahn, Ph.D. (Advisor); Jeffrey Peters, Ph.D. (Committee Member); Katie Hossler, Ph.D. (Committee Member)
Degree Name
Master of Science (MS)
Abstract
Coyotes are a generalist species that have adapted to nearly every terrestrial habitat in the United States. The species’ success is heavily attributed to their omnivorous diets and tolerance for environments that are regularly disturbed. Because the larger predator species that typically act as apex predators are sensitive to highly fragmented landscapes, the coyote is the functioning apex predator in many ecosystems where large predators, such as wolves, have been extirpated. The coyotes’ ecological role in urban ecosystems has received much attention in the last few decades as the species’ presence in cities and suburbs has increased, along with human-coyote conflicts. Anthropogenic supplementation, and reliance on anthropogenic food in particular, is regularly cited as the reason for coyotes being in urban areas. However, the inconsistencies reported in the literature indicate that the mechanisms driving coyotes into urban areas may be more complex than coyotes’ potential attraction to human food. Coyotes are foragers and scavengers whose diets reflect the seasonal and local availability of food, where prey items that are more abundant are likely to be encountered and consumed more frequently than prey that are hard to find. This is also what makes coyotes so successful in colonizing most types of habitats. The purpose of this study was to investigate how coyotes’ consumption of anthropogenic food varies between urban and non-urban habitats and if their consumption of anthropogenic food is selective or just a reflection of its increased availability in urban habitats. I conducted a meta-analysis on coyote dietary studies from 1975 to 2020 to identify trends in anthropogenic consumption and dietary composition in relation to habitat type, geographic region, season, and year of study. I also conducted a field study with scent-baited camera traps and scat analyses to test if coyotes in the Dayton area metroparks were attracted to anthropogenic food to the same degree as natural food, and to test if this attraction differed between urban and rural populations as a potential explanation for the increased prevalence of coyotes in urban areas. The scats were analyzed for δ13C and δ15N stable isotope ratios so that stable isotope mixing models could be used to estimate urban and rural coyote diet compositions from local prey isotope values. The results from the meta-analysis showed that coyote consumption of anthropogenic food is significantly higher in urban and agricultural habitats when compared to non-urban habitats (p < 0.05). Habitat type, geographic region, year of study, and season had a significant effect on consumption of natural prey categories, supporting coyotes’ behavior of consuming food items that are locally and seasonally abundant. The occupancy models used to analyze coyote detections at the scent-baited camera traps showed that neither urbanization level nor type of bait used had a significant influence on the number of coyotes detected. There was weak, but insignificant, evidence that coyotes were detected more frequently when the Fatty acid scent (the standard synthetic coyote attractant) tablet bait was used than the anthropogenic bait. The poor fit of all models indicates that the detectability of coyotes at these sites is influenced by factors not accounted for in this study. The stable isotope results showed that coyote diets in both urban and rural parks were primarily supported by a C3 plant-based food item that was not sampled in the prey dataset. Differences in anthropogenic consumption were not significant between the two populations; urban diets contained an average of 15% anthropogenic food while rural diets contained 8.6% anthropogenic food. Rabbits were the most important mammal prey item consumed in both locations. The dietary composition of the Dayton coyotes studied reflected the results from the meta-analysis, which showed that coyotes recognize anthropogenic food on the same scale they recognize natural food items and are not preferentially attracted to anthropogenic food in urban habitats and therefore likely rarely habituate to it or come to depend on it. Management strategies should be implemented to reduce the overall appeal of anthropogenic supplementation to coyotes and other urban species in order to lower the frequency of human-wildlife conflicts. Coyotes are here to stay in the cities, and their status as one of the few larger sized predators that tolerate— and yet avoid— humans reflects their unique ability to thrive in an urban habitat while retaining their wild, unhabituated nature.
Page Count
87
Department or Program
Department of Biological Sciences
Year Degree Awarded
2021
Copyright
Copyright 2021, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
