Species detection framework using automated recording units: a case study of the Critically Endangered Jerdon's courser

Abstract

With the advent of automated recording units, bioacoustic monitoring has become a popular tool for the collection of long-term data across extensive landscapes. Such methods involve two main components: hardware for audio data acquisition and software for analysis. In the acoustic monitoring of threatened species, a species-specific framework is often essential. Jerdon's courser Rhinoptilus bitorquatus is a Critically Endangered nocturnal bird endemic to a small region of the Eastern Ghats of India, last reported in 2008. Here we describe a reproducible and scalable acoustic detection framework for the species, comparing several commonly available hardware and detection methods and using existing software. We tested this protocol by collecting 24,349 h of data during 5 months. We analysed the data with two commercially available sound analysis programmes, following an analysis pipeline created for this species. Although we did not detect vocalizations of Jerdon's courser, this study provides a framework using a combination of hardware and software for future research that other conservation practitioners can implement. Vocal mimicry can aid or confound in detection and we highlight the potential role of mimicry in the detection of such threatened species. This species-specific acoustic detection framework can be scaled and tailored to monitor other species.

Challenges and opportunities for bioacoustics in the study of rare species in remote environments

“…Yet rare species may not be included in premade tools. Custom detectors can be developed from limited archival recordings with software like Raven Pro 2.0 (Cornell Lab of Ornithology, Ithaca) (see Arvind et al, 2022) or with few‐ and zero‐shot learning algorithms (Wang et al, 2021), and, for anurans in small‐scale deployments, pulse detection tools may be effective (Lapp et al, 2021).…”

“…Despite the challenges of data interpretation, and of even executing passive acoustic surveys in remote areas, any new data they yield may be valuable for endangered or data‐deficient species (e.g., Rojas‐Bracho et al, 2022). Thus, for rare, vocally active species, especially anurans, mammals, and birds, bioacoustics may be a powerful tool for conservation (Table 1) (Arvind et al, 2022; Neilson et al, 2013). The logistical challenges of accessing remote areas apply equally to active and passive surveys, and PAM may enable teams to visit more locations by alleviating the time pressure of conducting surveys exclusively during sometimes brief periods of species activity.…”

Solving the problem of biodiversity analysis of bird detection and classification in the video stream of camera traps

“…The project's camera [10] is installed on the territory of El Valle de Anton in the Cerro Gaital mountains (Figure 1) in Panama. The feeder is located 12 meters from the house and is filled with food several times every day between 5 am and 7 pm.…”

Playback-aided surveys and acoustic monitoring in the detection of the Endangered Forest OwletAthene blewitti

“…Previously, a study showed the Forest Owlet call can be heard at a distance of 1 km (Ishtiaq and Rahmani 2004); however, this species has a variety of vocalisations that have yet to be assessed systematically. ARUs have been used to detect several endangered species (Arvind et al 2023), and this is proving to be an efficient tool for the rapid assessment of threatened taxa.…”