Passive acoustic monitoring reveals seasonal patterns in European green toad calling activity but fails to accurately reflect population abundance.

ABSTRACT: Amphibians are among the most endangered groups of vertebrates worldwide; therefore, effective population monitoring is crucial for understanding the factors driving these unfavourable trends. In this study, we evaluated the effectiveness of fully automated passive acoustic monitoring in estimating the distribution and population size of the European green toad (Bufotes viridis)-an anuran species in which males vocalize intensively during the breeding season. We conducted visual counts with human observers, recorded the soundscape using autonomous sound recorders, applied automatic call detection, and calculated soundscape complexity using acoustic indices adjusted to the frequency range of European green toad vocalizations. Our algorithm generated a calling intensity index, which detected

SUBMITTER: Kaczmarski M 

PROVIDER: S-EPMC12279945 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature