Oral Presentation 64th International Conference of the Wildlife Disease Association 2015

Determining the role of fruit bat population dynamics in the emergence of Hendra virus in Australia (#7)

John R Giles 1 , Peggy Eby 2 , Alison J Peel 1 , Raina K Plowright 3 , Hamish McCallum 1
  1. Environmental Futures Research Institute, South Brisbane, QLD, Australia
  2. School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
  3. Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, USA

Hendra virus (HeV) is a bat-borne RNA virus that has recently emerged as a human public health concern in Australia. HeV circulates in the large frugivorous and nectarivorous bats of the genus Pteropus (known colloquially as fruit bats or flying foxes). Periodically, spillover into an intermediate host (horses) occurs which amplifies viral populations before infecting humans. Anthropogenic influence and landscape change have been implicated as catalysts in the emergence of HeV, as well as analogous bat-borne diseases, such as Ebola and Nipah virus. Therefore, a quantitative understanding of the mechanisms that drive host population dynamics and pathogen epidemiology within the context of landscape change is an important and elusive requisite to predicting the behavior of a bat-borne disease system.

Here, I present spatiotemporal models of both food resource distribution and foraging behavior of fruit bats, the combination of which enables a functional model of bat population dynamics at the landscape scale. My methods employ novel algorithms that analyze patterns in census counts at roosts of fruit bats across southeastern Queensland over the past decade, and mathematical models of social foraging behavior that characterize spatiotemporal flux of fruit bat populations over time. Some initial results indicate that large aggregations of bats are correlated with remotely sensed measures of eucalypt phenology, and the fission-fusion structure of bat populations appears to be driven by hyper-variable patterns of flowering and nectar production across the landscape.

Robust prediction of the mechanistic interaction between food resource variability and bat population distribution facilitates parameterization of epidemiological models of viral transmission that are not vulnerable to typical confounders such as spatial population heterogeneity. And more broadly, it allows construction of scenarios that demonstrate how landscape change quantitatively influences bat population dynamics and ultimately drives spillover and emergence of bat-borne pathogens.