Date of Award
Master of Science
Mesocarnivores, including bobcats (Lynx rufus) and coyotes (Canis latrans), fill a unique ecological role throughout much of North America, where they were once influenced by larger predators, but are now the top predators where large carnivores have been extirpated. Their adaptability, generalist traits, and ability to coexist with humans to a greater extent than many species makes them an important subject for current predator research. In addition, their recent population recovery in the case of bobcats and historical range expansion in the case of coyotes make their study timely given a potential increase in their influence on their prey and environments. I investigated how bobcats and coyotes in southern and central Illinois respond in their spatial behavior to factors in their environment like human modification and resources, including a local pulsed resource, white-tailed deer (Odocoileus virginianus) fawns. These spatial behaviors include home-ranging behaviors, habitat selection, and movement, which can be extremely informative in estimating how mesocarnivores respond to landscape heterogeneity. I found that individual variation, which is understudied in much of current spatial research, played a powerful role in all of these behaviors. Bobcats and coyotes used different strategies to respond to human modification in their home ranges, with bobcats broadly expanding their home range with increases in human modification, and clearly selecting for or avoiding these features on the landscape. Meanwhile, coyotes did not expand their home ranges with human modification, but instead displayed temporal and spatial complexity in their functional responses to human modification. These differences in response revealed a gradient in spatial behaviors animals can use to exist in anthropogenic environments, influenced by a species’ behavioral plasticity. I also found that while bobcat and coyote targeting of fawns during fawns’ most vulnerable period was weakly supported at the population-level, there was a substantial amount of individual variation in fawn exploitation. These results provided evidence that there were some specialist individuals that may contribute much more to fawn predation than others, which was somewhat influenced by habitat type. Overall, I found important interspecies and interindividual variation in mesocarnivore spatial behaviors. My study demonstrates how mesocarnivores respond to habitat and prey resources and risks associated with human development. Using this information, I present a framework for predicting how species may respond to changes in their environments, as well as provide further insight into how mesocarnivores may affect ungulate recruitment.
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