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

Abstract

AbstractSocial integration can affect an individual’s susceptibility to infectious disease. Conversely, infectious disease can reduce an individual’s social activity. Yet, it remains unclear to what extent short-term infections can inhibit aspects of long-term social integration (e.g., formation of new relationships). During a previous study on relationship formation, we captured female common vampire bats (Desmodus rotundus) from different wild populations and housed them together in captivity. Upon introduction, we observed an unplanned outbreak of bacterial infections that caused cutaneous lesions. After treating infected bats with an antibiotic, 5 bats recovered, but 4 others suffered lasting injuries. We analyzed how allogrooming rates changed over time among familiar and new pairs consisting of the 9 infected and 12 asymptomatic bats. Infected bats demonstrated lethargy and reduced social behavior. We found that more severely infected bats gave and received less allogrooming compared to asymptomatic bats, that this infection effect was initially larger for new pairs relative to familiar pairs, and that this effect decreased as infected bats recovered and new pairs became more familiar. These observed effects, although opportunistic and based on only 9 infected bats, were consistent with the hypothesis that short-term infections can impact relationship formation when new individuals join a group.