Tradition vs. innovation: comparing bioacoustics and mist-net results to bat sampling

Bats are a complex and diverse group, making their study remarkably challenging. Several methods allow the study of bats, e.g. mist-nets and acoustic monitoring (AM). We compare the use of AM and mist-nets to inventory bats in a mountainous region of São Paulo state, Brazil. We provide a species list for the study area based on species registered with both methodologies, comparing with a species list known for the state, obtained from the literature. We calculated beta diversity between methodologies to evaluate the dissimilarity in species composition sampled with these methods. We also performed a PCA to evaluate if the bat fauna sampled with AM showed species-habitat associations. We recorded 15 species/sonotypes through AM and 22 species through mist-nets. Beta diversity revealed 97% of dissimilarity in species composition. The turnover component explained 96% of this dissimilarity. PCA revealed that Vespertilionidae bats were associated with border/cluttered habitats, while Molossidae bats were present in all habitat types. The species list for the state comprises eighty species. Our inventory recorded more than 25% of this fauna. Mist-nets are efficient for sampling low-flying/low-intensity echolocating bats. AM is crucial for sampling high-flying/high-intensity echolocating bats. This is the second study to use AM to inventory bats in this state.