Land use, vampire bat feeding and rabies
A stable isotope analysis of bat hair, stomach contents and possible prey species showed some expected things, like that bats specialize on livestock prey when they don’t have any other options. But there were also some surprises. For example, on the coast of Peru vampire bats in the same colonies fed on very food resources spanning primary consumers to top predators. Similarly, in the Amazon rainforest, we found evidence of individuals that fed mostly or exclusively on livestock living next to individuals that fed mostly on wildlife. This led to some of the largest within-population variability in carbon and nitrogen stable isotopes ever recorded in animals, suggesting that when it comes to feeding, these bats have personality and stick to what they know. Another surprise was that the diversity of dietary strategies tended to decline with the local availability of livestock, diets were most diverse in places where there were some livestock and some wildlife available – these were also the kind of places where we found bats feeding on people. But, once livestock became abundant, bats seemed to switched entirely to this relatively easy prey source. In the Amazon, this seemed to be a good thing for human health: bat bites on people were common in places without livestock but totally absent where bats were specializing on domestic prey. All of this is interesting from a disease transmission standpoint because as land use change and human behavior alter bat feeding behavior, they also alter which species are at risk for rabies infection. Next up, we will conduct genetic analysis of bat blood meals to find out exactly which species are bitten and Dan will investigate whether dietary differences among bat colonies affects bat immunity and infection.
The paper is published free online at Journal of Applied Ecology.
Streicker, D.G. & Allgeier, J.E. From food web to disease ecology: foraging choices of vampire bats in diverse landscapes (2016) Journal of Applied Ecology. DOI: 10.1111/1365-2664.12690