Amphibian sound recordings in Brazil are geographically and taxonomically biased and cover less than two-thirds of native species

By Emerson José

A recent study involving researchers from São Paulo State University (Unesp) and published in December in the Biological Journal of the Linnean Society reveals that sound recordings of amphibians in Brazil show strong geographic and taxonomic biases. The research identified 26 amphibian species whose vocalizations had not yet been described by science, highlighting gaps in bioacoustic knowledge of Brazilian fauna.

The article, entitled “Amphibian sound recordings in Brazil are geographically and taxonomically biased and cover less than two-thirds of native species”, was developed with the participation of researchers associated with CBioClima (Center for Research on Biodiversity Dynamics and Climate Change), based at the Unesp campus in Rio Claro.

With more than 1,250 species, Brazil hosts the greatest amphibian diversity in the world. The study presents an overview of 15 sound collections maintained by Brazilian institutions, which gather recordings of vocalizations used in behavioral, ecological, and taxonomic studies. A total of 25,385 recordings were analyzed, resulting in a species list in which 26 species had their vocalizations described for the first time. The most represented families were Hylidae (48%) and Leptodactylidae (21%). Considering all collections, 798 species belonging to 24 families were represented, with 22,298 records of 725 native species and 178 records of 73 species that do not occur in the country. Although most recordings were obtained in Brazilian territory, records from 17 other countries were also identified, representing 1.4% of the total data.

In anurans—a group of amphibians that includes frogs and toads—acoustic communication plays a fundamental role at different stages of the life cycle, such as reproduction and territorial defense. Assessing species and their metadata through sound collections is a relevant strategy for identifying knowledge gaps and guiding future research in bioacoustics.

By conducting the first large-scale assessment of anuran recordings deposited in sound collections in Brazil, the study identified taxonomic, phylogenetic, and geographic biases in the distribution of records. These collections cover about 60% of the 1,250 anuran species currently recorded in Brazil, reinforcing the existence of significant gaps in bioacoustic knowledge.

The analysis of bioacoustic collections revealed that more than 30% of native species are not represented in audio collections, highlighting the need to expand and diversify these records. The study also emphasizes the importance of creating new bioacoustic collections and encouraging greater participation of civil society in data production, especially in currently underrepresented regions.

According to the authors, expanding and diversifying sound collections is essential to advance knowledge of biodiversity and support conservation strategies. Investing in new records and broader social participation can help reveal the still poorly known acoustic richness of Brazilian amphibians.

According to the authors, expanding and diversifying sound collections is essential to advance knowledge of biodiversity and support conservation strategies. Investing in new records and greater social participation can help reveal the still poorly known acoustic richness of Brazilian amphibians.

The full study is available at: https://doi.org/10.1093/biolinnean/blaf106