New Tools in Bioacoustics and Soundscape Ecology

Climate change and biodiversity loss threaten the sustainability of life on earth as we knew it. If we want to slow down and eventually reverse some of these changes, we need not only to improve our knowledge about biodiversity (e.g., how many species there are), but also better understand the ways people connect with nature. In other words, we can't love what we don't know, and we won't protect what we don't love.

Sound is a critical component of wildlife behavior and therefore for ecosystem functioning. As humans evolved using these sounds to navigate the wilderness, they also play an important role in the way we perceive and interact with the natural world. However, much work is still needed to fully understand the diversity that natural soundscapes represent and the ways people use them to develop deep ties with nature. This dissertation is my contribution to these efforts.

The first chapter describes Rthoptera, a new R package to visualize and analyze sounds of insects, with a focus on Orthoptera (i.e., grasshoppers, crickets, and katydids). Besides making classic plot types and measurements freely accessible in a single tool, Rthoptera delivers new metrics which can be used to unveil variability at the smallest analytical levels. Finally, users not familiar with R programming can still leverage its power by launching one of the 17 Shiny applications that allows them to interactively produce the same output as from the R functions.

The second chapter leverages the flexibility of Rthoptera to characterize the sounds of 20 Ensifera (Insecta: Orthoptera) species from central Chile for the first time, launching the study of the sounds in this taxa in the country. The recordings were obtained during several summer seasons from 2015 to 2025, covering the regions of Coquimbo, Valparaíso, Santiago, O'Higgins, Maule, Biobío, and Araucanía. Of particular relevance is the detailed analysis of the tribe Aphractini (Tettigoniidae: Phaneropteridae), with 4 known genera. Within this tribe, bioacoustic analysis allowed us to distinguish at least 4 species within a species complex in the genus Polycleptis. Posterior molecular analysis of the same populations revealed cryptic species coinciding with our bioacoustics estimates.

The third chapter shifts focus to the human perception of wildlife sounds and its implications for nature connectedness, place attachment, and mental health. Using a mixed methods approach, this study combines participatory GIS, interviews, surveys, and a listening experiment to reveal the upbringing factors influencing access to nature and natural soundscapes and perception of bird sounds from the home place in Colombian and Bangladeshi students at Purdue University, USA.