Resilience and virus ecology of paleotropical bats

Emerging infectious diseases (EIDs) are a threat to human and animal health. Bats are known reservoir hosts for various highly fatal viruses associated with EIDs. Previously, outbreaks of some EIDs were directly associated with environmental conditions, namely an increased contact zone between reservoir hosts and humans resulting from bush-meat consumption and increasing anthropogenic land-use. However, anthropogenic land-use, especially habitat logging and fragmentation, may also take effect via consequences upon wildlife communities, including population declines. Before effects manifest in decreased population sizes, individuals may show changes in physiological parameters. In this project, I investigated if habitat logging and fragmentation are associated with changes in body mass, levels of chronic stress, immunity and occurrence of viruses in bats. I sampled individuals of eight bat species of the genus Rhinolophus, Hipposideros and Kerivoula at the SASFE project in Sabah, Malaysia. I found that individuals of foliage-roosting bat species weighed less in currently logged and recently fragmented habitats and had lower white blood cell counts than their conspecifics from undisturbed forests. In a cave-roosting species (Rhinolophus borneensis) individuals from fragmented forests showed higher levels of chronic stress (indicated by the neutrophil to lymphocyte ratio) than conspecifics from actively logged forests. Overall, I conclude that foliage-roosting bat species may be particularly vulnerable to habitat fragmentation, affecting their overall health including cell-mediated immunity. Further, I investigated if the detrimental effects of habitat logging and fragmentation on the overall health of bats are reflected in increased detection rates of corona- and astroviruses in fecal samples of bats in the same study site. An increase in detection rates may increase the risk for pathogen spill-overs from bats to humans. Unexpectedly, the detection rates were not associated with habitat logging and fragmentation in any species. However, I identified the rainy season as a risk factor for increased astrovirus shedding. Further, individuals in poor body condition tended to have a higher risk for astrovirus shedding. In conclusion, foliage-roosting bat species may turn into a source for future viral spillover events if they are sufficiently resistant to remain in logged and fragmented habitats. Ongoing landscape fragmentation in Southeast Asia and worldwide will reduce the connectivity of remaining habitats, resulting in lower mobility and genetic diversity of bats within a species in future generations. These bat populations may have a higher susceptibility to contract and shed viruses especially during the rainy season. If humans or their livestock live nearby, these viruses or other pathogens may spill over in new hosts.

Authors

• Seltmann, Anne — Leibniz Institute for Zoo and Wildlife Research
• Corman, Victor M
• Rasche, Andrea
• Drosten, Christian
• Courtiol, Alexandre
• Czirjak, Gabor A
• Bernard, Henry
• Struebig, Matthew
• Voigt, Christian

Keywords

• Bats
• Harp trapping
• Anthropogenic disturbance
• body mass
• chronic stress
• fragmentation
• white blood cell count
• coronaviruses
• astroviruses
• coinfection
• habitat fragmentation
• human-modified landscapes

Funders

• German Research Council (DFG Priority Programm 1596; Vo890/23, DR772/10-1 and 2)
• UK NERC Natural Environment Research Council (HTMF Human-Modified Tropical Forests program under the LOMBoK Land-Use Options for Maintaining Biodiversity and Ecosystem Function consortium)

Permits

• Research — Sabah Biodiversity Council (JKM/MBS.1000-2/2 JLD.3 (153))
• Research — Sabah Biodiversity Council (JKM/MBS.1000-2/2 JLD.3 (317))
• Research — Sabah Biodiversity Council (JKM/MBS.1000-2/3 JLD.2 (16))

Worksheets

Files

• Seltmann_bat_data_V2.xlsx
• Traps2014.2015.gpx

Taxa

50 GBIF taxa, 0 sequence-derived taxa.