Ecological Potential for Rabies Virus Transmission via Scavenging of Dead Bats by Mesocarnivores

Multiple species of bats are reservoirs of rabies virus in the Americas and are occasionally the source of spillover infections into mesocarnivore species. Although rabies transmission generally is assumed to occur via bite, laboratory studies have demonstrated the potential for rabies transmission via ingestion of rabid animals. We investigated the ecological potential for this mode of transmission by assessing mesocarnivore scavenging behavior of dead bats in suburban habitats of Flagstaff, Arizona, US. In autumn 2013, summer 2014, and autumn 2015, we placed 104 rabies-negative bat carcasses either near buildings, in wildland areas, or in residential yards and then monitored them with trail cameras for 5 d. Overall, 52 (50%) bat carcasses were scavenged, with 39 (75%) of those scavenged by striped skunks ( Mephitis mephitis ). Within our study area, striped skunks had a higher ecological potential to contract rabies via ingestion of bat carcasses compared to other mesocarnivore species, due both to a greater number of encounters and a higher probability of ingestion per encounter (91%), and they were significantly more likely to approach bat carcasses in yards than in wildland areas. Raccoons ( Procyon lotor ) and gray foxes ( Urocyon cinereoargenteus ) had fewer encounters (nine and 13, respectively) and lower probability of ingesting bats (33% and 8%, respectively).