Human activities create novel food resources that can alter wildlife–pathogen interactions. If resources amplify or dampen, pathogen transmission probably depends on both host ecology and pathogen biology, but studies that measure responses to provisioning across both scales are rare. We tested these relationships with a 4-year study of 369 common vampire bats across 10 sites in Peru and Belize that differ in the abundance of livestock, an important anthropogenic food source. We quantified innate and adaptive immunity from bats and assessed infection with two common bacteria. We predicted that abundant livestock could reduce starvation and foraging effort, allowing for greater investments in immunity. Bats from high-livestock sites had higher microbicidal activity and proportions of neutrophils but lower immunoglobulin G and proportions of lymphocytes, suggesting more investment in innate relative to adaptive immunity and either greater chronic stress or pathogen exposure. This relationship was most pronounced in reproductive bats, which were also more common in high-livestock sites, suggesting feedbacks between demographic correlates of provisioning and immunity. Infection with both Bartonella and haemoplasmas were correlated with similar immune profiles, and both pathogens tended to be less prevalent in high-livestock sites, although effects were weaker for haemoplasmas. These differing responses to provisioning might therefore reflect distinct transmission processes. Predicting how provisioning alters host–pathogen interactions requires considering how both within-host processes and transmission modes respond to resource shifts. This article is part of the theme issue ‘Anthropogenic resource subsidies and host–parasite dynamics in wildlife’.
|Journal||Philosophical Transactions of the Royal Society B: Biological Sciences|
|State||Published - 5 May 2018|
Bibliographical noteFunding Information:
authors contributed to manuscript revisions and gave their final approval for publication. Competing interests. We have no competing interests. Funding. D.J.B. was supported by a National Science Foundation Graduate Research Fellowship, ARCS Foundation Award, Sigma Xi, Animal Behavior Society, Bat Conservation International, American Society of Mammalogists, Odum School of Ecology, UGA Graduate School, UGA Latin American and Caribbean Studies Institute, UGA Biomedical and Health Sciences Institute, Explorer’s Club and NSF Doctoral Dissertation Improvement Grant (DEB-1601052); fieldwork was also supported by NSF DEB-1020966. G.A.C. was supported by the Leibniz Institute for Zoo and Wildlife Research. A.B.B. was supported by an NSF Graduate Research Fellowship, the American Society of Mammalogists and a UGA Global Programs International Travel Award. KJN was funded by NSF DEB-1518611. Fieldwork by N.B.S. was supported by the American Museum of Natural History Taxonomic Mammalogy Fund. A.T.G. was supported by the USDA National Rabies Management Program. S.A. acknowledges support from NSF DEB-1518611, and D.G.S. was supported by a Sir Henry Dale Fellowship, jointly funded by the Wellcome Trust and Royal Society (102507/Z/13/Z).
© 2018 The Authors.
- Resource provisioning
- Supplemental feeding