An exploration of ecoacoustics and its applications in conservation ecology A. Farina a,* , B. Krause b , T.C. Mullet c a Department of Pure and Applied Sciences, Urbino University, Urbino, Italy b Wild Sanctuary, Inc., Sonoma, California, United States c Renewable Energy Coordination Offce, Bureau of Land Management, Phoenix, AZ, United States A R T I C L E INFO Keywords: Conservation ecology Ecoacoustics Sonoscape Soundscape Sonosphere Sonotope Ecoacoustic indices ABSTRACT Our planet is facing unprecedented adversity due to the global impacts of climate change and an emerging sixth mass extinction. These impacts are exacerbated by population and industrial growth, where increased resource extraction is required to meet our insatiable demands. Yet, the tangible elements of our lone inhabited planet in the solar system are not the only things disappearing or being modifed. The sounds of Earth are being altered in ways that may never be recovered. Indeed, we occupy a noisier world in this age of machines that comes at a great expense in the form of sonic extinctions. It is profoundly apparent, yet not widely recognized, that con- servation efforts must consider the importance of the sonic environment (i.e., sonosphere). Although sound has been integral to life for millions of years, our understanding of its ecological role has only just begun. Sounds are one of the most important extensions of the organismic inner world, becoming testimonials of environmental complexity, integration, and relationships between apparently separated parts. From a semiotic perspective, sounds are signals utilized by many organisms to save energy in patrolling, defending, exploring, and navigating their surroundings. Sounds are tools that establish dynamic biological and ecological competencies through refned partitioning in the natural selection process of evolution. Ecoacoustics is a recent scientifc discipline that aims to investigate the role of sound in ecological processes. Despite its youth, Ecoacoustics has had rapid theoretical and applied growth, consolidating a diverse array of research on the ecology of sounds across many disciplines. Here, we present how Ecoacoustics plays a signifcant role in conservation ecology by exploring the discipline’s theoretical framework, new descriptors of sonic complexity, and innovative methods for supporting conservation efforts from singular species to entire landscapes across local and global scales. The combination of automated recording units and ecoacoustic indices present a very promising approach to the study of remote areas, rare species, and data rich analyses. While Ecoacoustics scientists continue to explore this new scientifc horizon, we encourage others to consider Ecoacoustics in their conservation agendas because of its application to the study and management of terrestrial, marine, and freshwater habitats. 1. Introduction The escalating deterioration of natural ecosystems, combined with an epidemic of species extinctions worldwide, urgently demands an intensive and effcient application of conservation practices in order to reduce the catastrophic impacts human activities are having on the Biosphere (Secretariat of the Convention on Biological Diversity, 2020). Concurrently, a consequence of these impacts includes the emergence of machine-generated noise and the alterations and extinctions of natural sounds (Monacchi, 2013; Dimock, 2016; Hui, 2021). The intimate relationship that sonic environments have with these catastrophic phe- nomena lays the groundwork for a tangible and meaningful role Ecoacoustics can have in both local and global conservation agendas. Ecoacoustics is a recent discipline that intentionally focuses on the sonic properties of the environment and their potential application to explore ecological complexity at different spatial and temporal scales (Sueur and Farina, 2015). In 2014, an international meeting organized in Paris, formalized “Ecoacoustics" as a holistic feld of study with the aim to offer a broad multidisciplinary approach to assess the environmental quality of sonic signals and monitor their ecological dynamics at multiple scales from individual species to land- and seascapes (Farina and Reid, 2020). The scientifc framework of Ecoacoustics is based on the frst fve fundamental principles of Ecological Theory (Scheiner and Willig, 2008). * Corresponding author. E-mail address: almo.farina@uniurb.it (A. Farina). Contents lists available at ScienceDirect BioSystems journal homepage: www.elsevier.com/locate/biosystems https://doi.org/10.1016/j.biosystems.2024.105296 Received 16 May 2024; Received in revised form 8 August 2024; Accepted 9 August 2024 BioSystems 245 (2024) 105296 Available online 15 August 2024 0303-2647/© 2024 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.