Investigating passive airborne eDNA detection of bats at artificial feeding stations

While previous studies demonstrated airborne detection of bats from roosts using active air sampling, it remains uncertain whether bats can be detected from the open air using passive approaches. Outside two cave sites in Texas, we positioned passive air samplers by ultra-violet light lures, which increase bat activity by attracting insect prey. We used multiple eDNA extraction methods on air collection media with metabarcoding-based detection (Species from Feces cytochrome oxidase subunit I marker; 202 bp): direct DNA extraction and two resuspension-concentration approaches (filtration and pelleting). Using the direct extraction method, metabarcoding allowed detection of two bat species within a single sample, but the pelleting extraction method substantially improved taxonomic recovery of vertebrates and sample success overall.