Bioacoustics for in situ validation of species distribution modelling: An example with bats in Brazil

Abstract

Species distribution modelling (SDM) gained importance on biodiversity distribution and conservation studies worldwide, including prioritizing areas for public policies and international treaties. Useful for large-scale approaches and species distribution estimates, it is a plus considering that a minor fraction of the planet is adequately sampled. However, minimizing errors is challenging, but essential, considering the uses and consequences of such models. In situ validation of the SDM outputs should be a key-step—in some cases, urgent. Bioacoustics can be used to validate and refine those outputs, especially if the focal species’ vocalizations are conspicuous and species-specific. This is the case of echolocating bats. Here, we used extensive acoustic monitoring (>120 validation points over an area of >758,000 km2, and producing >300,000 sound files) to validate MaxEnt outputs for six neotropical bat species in a poorly-sampled region of Brazil. Based on in situ validation, we evaluated four threshold-dependent theoretical evaluation metrics’ ability in predicting models’ performance. We also assessed the performance of three widely used thresholds to convert continuous SDMs into presence/absence maps. We demonstrated that MaxEnt produces very different outputs, requiring a careful choice on thresholds and modeling parameters. Although all theoretical evaluation metrics studied were positively correlated with accuracy, we empirically demonstrated that metrics based on specificity-sensitivity and sensitivity-precision are better for testing models, considering that most SDMs are based on unbalanced data. Without independent field validation, we found that using an arbitrary threshold for modelling can be a precarious approach with many possible outcomes, even after getting good evaluation scores. Bioacoustics proved to be important for validating SDMs for the six bat species analyzed, allowing a better refinement of SDMs in large and under-sampled regions, with relatively low sampling effort. Regardless of the species assessing method used, our research highlighted the vital necessity of in situ validation for SDMs.

Morcegos no Parque Nacional do Catimbau, Pernambuco, Brasil: Síntese de uma década (2012-2022) de pesquisas

“…Registros no parque também ajudam a entender melhor a distribuição de várias espécies, pois preenchem lacunas de registros, expandem ou refinam limites de distribuição previamente conhecidos (e.g. Hintze et al, 2018;Weber et al, 2019;Hintze et al, 2021).…”

“…A bioacústica indicou que algumas espécies, como Promops centralis e Promops nasutus, ou Noctilio leporinus, são mais comuns e amplamente distribuídas do que o indicado pelo uso exclusivo de redes como principal método amostral (Veja Hintze et al, 2018;Hintze et al, 2021). Para avançarmos no registro de mais espécies no PARNA Catimbau serão necessários esforços concentrados em áreas com corpos de água junto a formações rochosas, em áreas de vegetação mais arbórea, em bolsões mais úmidos, próximos a plantações de espécies frutíferas, além da ampliação dos esforços na amostragem de cavernas e em construções humanas.…”

Sounds of the underground reflect soil biodiversity dynamics across a grassy woodland restoration chronosequence

“…Ecoacoustics has been used to monitor elusive and protected species in several ecological contexts. For instance, passive acoustic monitoring (PAM), which involves using autonomous acoustic sensors to record biological sounds (known as “biophony”), has been widely used to detect various taxonomic groups in terrestrial ecosystems, including birds (Abrahams, 2019; Abrahams & Geary, 2020), bats (Hintze et al 2021; López-Baucells et al 2021), and invertebrates (Harvey et al 2011; van der Mescht et al 2021; Mankin et al 2018; Mankin, 2022; Greenhalgh et al 2023). It is also used in aquatic systems to monitor cetaceans (Jones et al 2020; Guidi et al 2021), amphibians (Gan et al 2020), crustaceans (Kühn et al 2022), and fish (Popper & Hawkins, 2019; Desjonquères et al 2020).…”

The sound of restored soil: using ecoacoustics to measure soil biodiversity in a temperate forest restoration context

“…In recent years, ecoacoustics has been applied to monitor elusive species in several environmental contexts––particularly in conservation biology (Teixeira et al 2019; Greenhalgh et al 2020; Stowell & Sueur 2020). For instance, passive acoustic monitoring (often shortened to “PAM”), which involves deploying autonomous acoustic sensors, has been used to collect recordings of biological sounds (known as “biophony”) from bats (Hintze et al 2021; López‐Baucells et al 2021), birds (Abrahams 2019; Abrahams & Geary 2020), and invertebrates (Harvey et al 2011; van der Mescht et al 2021; Mankin 2022) in terrestrial environments; and cetaceans (Jones et al 2020; Guidi et al 2021), amphibians (Gan et al 2020), crustaceans (Kühn et al 2022), and fish (Popper & Hawkins 2019) in aquatic environments. Indeed, ecoacoustics has emerged as an efficient tool to measure and monitor biodiversity and has the potential to enhance the toolbox of restoration ecologists, as demonstrated by preliminary studies of aquatic and terrestrial restoration projects (Greenhalgh et al 2021; Znidersic & Watson 2022).…”