Original ArticlesSoundscape analysis and acoustic monitoring document impacts of natural gas exploration on biodiversity in a tropical forest

- Impacts of hydrocarbon exploration on biodiversity in tropical forests are poorly understood.
- We used passive acoustic monitoring to investigate how soundscapes, and avian and anuran composition respond to a natural gas exploratory well.
- Soundscapes differed by distance and by operational phase (construction vs drilling).
- Birds and frogs responded differently to operations, and among birds, insectivores were detected more frequently further from the well.
- Acoustic monitoring and soundscape analyses should be used as best practices in monitoring biodiversity and for guiding mitigation strategies.

Natural resource extraction is increasing rapidly in tropical forests, but we lag behind in understanding the impacts of these disturbances on biodiversity. In high diversity tropical habitats, acoustic monitoring is an efficient tool for sampling a large proportion of the fauna across varied spatial and temporal scales. We used passive acoustic monitoring in a pre-montane forest in Peru to investigate how soundscape composition and richness of acoustic frequencies varied with distance from a natural gas exploratory well and with operational phase (construction and drilling). We also evaluated how anuran and avian species richness and vocal activity varied with distance and between phases. Soundscape analyses showed that acoustic frequency similarity was greatest among sites closer to (≤250 m) and farther from (≥500 m) the platform. Soundscapes revealed more frequencies were used during construction and showed a weak trend of increasing frequency richness with increasing distance from the disturbance. Avian species richness and detections increased with distance from the platform, but anuran richness and detections declined with distance. Operational phase did not play a significant role in overall richness or activity patterns of either group. Among birds, insectivore detections increased with distance from the platform, and nectarivores were detected more frequently during the drilling phase. Results demonstrate that acoustic monitoring and soundscape analyses are useful tools for evaluating the impact of development activity on the vocalizing community, and should be implemented as a best practice in monitoring biodiversity and for guiding specific mitigation strategies.