Files
Abstract
Many wildlife species have established semi-permanent or year-round populations in urban landscapes. Animals in cities can often access predictable and abundant resources, but at the same time might experience lowered diet quality, exposure to toxicants and stressors, and greater pathogen transmission. The health of urban wildlife is relevant to humans, especially given risks of zoonotic pathogen transmission. The aim of this dissertation is to investigate how urban landscape features, including altered resources and exposure to toxicants, can change wildlife behavior, health, and infectious disease. I first synthesized the literature to quantify the extent to which urbanization affects four metrics of wildlife health; this meta-analysis demonstrated an overall small but significant negative effect of urbanization on wildlife health, driven by higher toxicant loads and greater parasitism by parasites transmitted through close contact. I next examined the individual and environmental predictors of foraging movements of wild flying foxes in a recently-established urban population in Adelaide, South Australia. This work showed that flying foxes were significantly more likely to forage at sites more intensively used by humans, and that flying foxes in better body condition flew shorter distances each night, visited fewer foraging sites, and had smaller foraging areas. Using data from flying foxes captured in Adelaide and seven other locations across Australia, I next examined individual and environmental predictors of metal concentrations in bat fur, and associations between metals and bat parasitism. This study demonstrated that flying foxes captured at sites surrounded by greater human modification had higher metal concentrations in fur, and provided evidence for positive and negative relationships between ectoparasite abundance and metal concentrations. Lastly, I developed a mechanistic model of host-parasite dynamics to understand the interactive consequences of pathogens and toxicants on infection dynamics and population size of wildlife in an urbanizing landscape. Results suggested the extent of contaminated habitat across the landscape could enhance or reduce impacts of infection on host populations. Collectively, this dissertation provides evidence for multiple sublethal effects of urban landscapes for wildlife, and suggests important gaps for future work on the movement and survival consequences of toxicant exposure in wildlife.