A Case Study: Using Passive Acoustic Monitoring Devices In A Growing Urban Landscape To Monitor Avian Diversity

With the increase of urbanization around the world, key habitats such as grasslands and scrublands are disappearing, posing significant threats to species that rely on such habitats. Passive acoustic monitoring (PAM) has started to gain interest as a reliable tool for biodiversity monitoring. This study assesses whether PAM can be an effective way to monitor biodiversity with relatively low effort when compared to traditional survey methods. Using PAM, a mixed grassland and scrubland ecosystem was monitored for five months for avifaunal diversity. Data that was collected from dusk to dawn using audio recorders deployed on the study site were run through BirdNET analyzer under default detectors. Top detections for each species were compared with avian vocalization libraries manually. Out of 135 species detected, 76 were true positives, resulting in a species identification accuracy of 56.3%. Notably, among the species that were true detections, 21 species were found to have confidence scores larger than 0.99. In addition, 15 of the detected species were found to be migratory in this area, and three were found to be rare. This study demonstrates how PAM can be used to monitor biodiversity in a species-rich but understudied area such as Southern India, to identify both cryptic and nocturnal species that might be omitted from standard field surveys.