The Role of Anthropogenic Roosting Ecology in Shaping Viral Outcomes in Bats

The ability of some wildlife to live in anthropogenic structures in response to rapid land-use change is widely observed across mammals. However, the influence of this adaptation in shaping viral hosting ability and diversity are not well understood, especially for the order Chiroptera. Anthropogenic roosting may have important consequences for predicting virus spillover and spillback risk, particularly as the propensity of bats to roost in anthropogenic structures (e.g., buildings, bridges, homes, and tunnels, etc.) directly relates to human exposure. Here, we integrate novel roosting ecology data with a machine learning approach to assess the importance of anthropogenic roosting in predicting viral outcomes and evaluate if this novel trait improves prediction of undetected but likely host species. Our results show that the importance of anthropogenic roosting varies moderately across viral outcomes. Anthropogenic roosting is most important for predicting virus hosting ability across bats, followed by zoonotic hosting ability, viral richness, and the proportion of viruses that are zoonotic. Anthropogenic roosting status is less important than human population density but more important than most family, diet, and foraging traits of bat species, and models with anthropogenic roosting predict a narrowed list of undetected virus hosts compared to models excluding this trait. We identified 35 bat species likely to host a virus, 18 of which roost in anthropogenic structures. Additionally, we identified 51 undetected zoonotic host species, 30 of which are anthropogenic roosting. Maps of predicted virus host distributions show distinct spatial patterns between anthropogenic and exclusively natural-roosting bats. These findings suggest that anthropogenic roosting has a non-trivial role in shaping viral outcomes in bats, specifically virus hosting ability. ### Competing Interest Statement The authors have declared no competing interest.