Relatedness and genetic structure of big brown bat (Eptesicus fuscus) maternity colonies in an urban-wildland interface with periodic rabies virus outbreaks

Big brown bats (Eptesicus fuscus) are the bat species in North America most frequently found to be rabid because of their high rate of human contact and thus submissions for rabies testing, of which, 4–5% are positive. The social behavior of big brown bats during the summer months may drive space use and potential viral exposure to conspecifics and mesocarnivores. We collected 88 unique genetic samples via buccal swabs from big brown bats captured at four maternity roosts surrounding a golf course during the summer of 2013. We used seven microsatellite loci to estimate genetic relatedness among individuals and genetic structure within and among colonies to infer whether females selected roosts based on kinship and used genetics and radio telemetry to determine the frequency of roost switching. We found roost switching through genetics and telemetry, and no evidence of elevated genetic relatedness within colonies or genetic structure among colonies. Social cohesion based on relatedness may not act to constrain the pathogen to a particular roost area, and thus, geographic mobility may increase viral exposure of bats in neighboring areas.