Molecular genetic analysis of air, water, and soil to detect big brown bats in North America

Abstract

Cave-hibernating bats are widespread in North America but are facing precipitous population declines due to the impacts of white-nose syndrome (WNS). It is in winter hibernacula that bats are most vulnerable to the fungus that causes WNS, but the locations of over-wintering sites in western North America are largely unknown. This poses a significant challenge for bat monitoring, disease surveillance, and management efforts at the disease front. To advance initiatives to locate bats on the landscape, we developed real-time PCR assays to detect big brown bats (Eptesicus fuscus) from environmental DNA samples (eDNA). Three assays were designed, one each for eastern, western, and southern North America, to account for the high intra-specific genetic variability within big brown bats. We demonstrate that these assays can detect bat DNA in environmental samples, including air, water, and soil, and are able to detect target DNA at concentrations as low as 2 copies per reaction. Although the assays are highly sensitive, detections from samples collected in field samples were modest. Our findings suggest that eDNA may provide a much-needed, non-invasive alternative to conventional tools used to detect bats on the landscape but require further research to optimize their field application.