Rodent assemblages and rodent associated pathogens in a counter-urbanizing landscape

Human population declines in urban centers (also known as counter-urbanization) can result in increased levels of vacancy and infrastructure loss, though relatively little is known regarding the ecological outcomes of this type of landscape change. The abundance and diversity of pest and zoonotic pathogen hosts are predicted to increase in counter-urbanizing environments, giving rise to a novel human-animal interface. Furthermore, the human-animal interface is a key location for zoonotic pathogen emergence, thus, understanding how host communities shift in regard to counter-urbanization can lend insight into risk of zoonotic pathogens in these areas.In this dissertation, I investigate the abundance and diversity of rodent hosts across a counter-urbanizing environment in the city of New Orleans, Louisiana, USA to understand how features of the urban environment shape rodent assemblages and the risk of zoonotic pathogens. I demonstrate that rodent abundance and diversity increase in areas with higher levels of vacancy, and that increased rodent abundance and diversity also translate to increased risk from some zoonotic pathogens. However, this work also indicates that not all zoonotic pathogens show similar patterns across the landscape. In this work I provide practical insight into specific environmental and sociological risk factors associated with rodent abundance and zoonotic pathogens, while also leveraging the gradient of rodent abundance and diversity present in the counter-urbanizing environment of New Orleans to test predictions regarding relationships between host diversity, host abundance, pathogen prevalence, and diversity.