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 Sao 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.

Automated summary

Bats are a complex and diverse group, and studying them can be challenging. This study compares the use of two methods, acoustic monitoring and mist-nets, to inventory bats in a mountainous region of Sao Paulo state, Brazil. The results show a high dissimilarity in species composition between the two methods, with turnover being the main factor. Additionally, the study finds associations between certain bat species and different habitat types using PCA analysis.