“Livestock-dense habitat functions as an ecological trap for vampire bats: immunological evidence”
4 January 2016
Society for Integrative & Comparative Biology Annual Meeting
Oregon Convention Center
Portland, Oregon, USA
Urbanization and agriculture cause declines for many wildlife, but some species benefit from human-provided food. The abundance and predictability of these provisioned resources can affect wildlife behavior and physiology and in turn alter infectious disease dynamics. Specifically, host condition and immune defense responses to resource shifts are key to understanding whether provisioning amplifies or dampens pathogen transmission. We here tested relationships between provisioning, host condition, and immunity through a cross-sectional study of vampire bats (Desmodus rotundus) in Peru and Belize. This hematophagous species has potentially benefited from intensification of livestock rearing, which could reduce starvation stress and energy spent during foraging, allowing bats to invest more in immunity. We predicted that bats captured in sites of high livestock density would be in better body condition, display less chronic stress and inflammation, and have higher investment in humoral immunity. Contrary to this prediction, we found increasing livestock density was associated with poorer condition, greater levels of stress and inflammation, and lower IgG, and that these negative health impacts were more severe in reproductively active bats. We also found that although livestock intensification was associated with impaired bat health, capture success increased with livestock density. Together these results suggest livestock-dense habitats could function as ecological traps by producing source populations of immunologically impaired vampire bats. Increasing the relative abundance of such habitat could have profound impacts on bat susceptibility to zoonotic pathogens and the spatial spread of infections.