UNDERSTANDING THE INFLUENCE OF ANTHROPOGENIC HABITAT MODIFICATION ON URBAN ANIMALS: CASE STUDIES OF CARRIBEAN LIZARDS AND NORTH AMERICAN MAMMALS

Abstract

Global urbanization is rapidly expanding, leading to habitat degradation and fragmentation, which present strong challenges for native wildlife. At the same time, urbanization is often accompanied by the introduction of non-native species, which alter community and habitat structures. These changes may disrupt ecosystem functions upon which animals and humans rely. Therefore, it is essential to understand the impact of anthropogenic habitat modifications on urban animals. In this dissertation, I use three case studies to examine anthropogenic influences on 1) species dispersal in Caribbean lizards, 2) mammalian behavior along an urban-rural gradient, 3) tick-borne disease host and vector communities. In my first chapter, I examined the influence of urbanization and road networks on dispersal of three lizard species in the context of their development tolerance. I found that development tolerance is a key predictor of dispersal impact, with the least tolerant species experiencing dispersal restriction and the most tolerant species experiencing dispersal facilitation. In my second and third chapters, I investigated the influence of urbanization and invasive understory vegetation along an urban-rural gradient in southeastern Pennsylvania. The second chapter focused on behavioral responses of four urban-adapted mammal species to urbanization across temporal and spatial scales. I found that behavioral changes were not driven by landscape-scale development, but rather by temporal and local-scale variables, most importantly local vegetation structure. Finally, in my third chapter, I again examined the effects of landscape-scale urbanization and local-scale vegetation density, this time in relation to tick-borne disease dynamics. My results suggest that invasive vegetation influenced small mammal and tick habitat use at micro-habitat scales, with important ramifications for tick-borne disease infection. In combination, the results from my three disparate chapters add to our understanding of anthropogenic impacts on urban animals.