Opportunistic evidence of the impact of bacterial infections on social integration in vampire bats

Abstract

Social integration affects an individual's susceptibility to infection, and conversely, infectious disease can reduce their social activity. It remains unclear, however, to what extent short-term infections might affect the formation of enduring social bonds. During a previous study on the formation of new allogrooming relationships among 21 common vampire bats (Desmodus rotundus), we used antibiotics to treat unplanned Staphylococcus infections in 9 bats, including 5 bats that recovered and 4 bats that suffered lasting injuries that prevented sustained flight. We compared the behaviors of the Staphylococcus-infected bats to healthy controls, and analyzed changes in allogrooming over time among infected and healthy bats that were familiar or unfamiliar. Relative to healthy bats, the 9 Staphylococcus-infected bats spent less time moving and allogrooming, and the 4 bats that suffered injuries received less grooming from new partners. These differences faded during 3 months of recovery. This pattern is consistent with the hypothesis that acute infections impact the development of social relationships. Our findings raise questions about how short-term infections might impact long-term social integration or partner choice.