Hoover Pantoja-Sánchez

Music has been recognized as an artistic and therapeutic stimulus in humans and other animals. In rodents, most auditory enrichment studies have relied on human-composed music within the human auditory range, overlooking species-specific acoustic perception. Mice communicate mainly in the ultrasonic range (>20 kHz), particularly during courtship, producing structured songs with complex syllables and phrases. To address this gap, we developed and tested a digital ultrasonic music program inspired by murine courtship songs using vocalizations from BALB/c and C57BL/6 strains. Songs were recorded, behaviorally contextualized, and digitally adapted into structured ultrasonic stimuli. Enrichment did not induce anxiogenic effects. In BALB/c mice, ethograms and plus-maze testing revealed increased exploratory behavior in stimulated groups, while C57BL/6 mice showed more variable responses. No adverse effects were observed. This study provides a systematic approach to species-tailored ultrasonic music, generating both behavioral insights and a bioacoustic library that may support replicable protocols in animal enrichment, neuroscience, and welfare research.

Sexual selection often favors the evolution of conspicuous mating displays. Emitting such overt displays carries the risk of interception by eavesdropping enemies, i.e. predators, parasitoids and parasites that exploit communication systems to find and attack their signaling victims. Yet, many signalers respond to variation in perceived eavesdropper risk, protecting themselves through risk-dependent inducible defenses to mitigate potential costs. Given that signalers are embedded in communication networks in which they interact with other signalers, target receivers and multiple eavesdropping enemies, here we investigated how variation in signaling and defensive strategies impacted by an eavesdropping enemy (frog-biting midges; Diptera: Corethrellidae) affects other receivers in a communication network. Ultimately, we aimed to determine whether and to what extent effects that cascade throughout the network shape relative fitness among chorusing males. Using female choice experiments with túngara frogs (Engystomops pustulosus) and predation experiments with eavesdropping, fringe-lipped bats (Trachops cirrhosus), we show that variation in the call elaboration and defensive strategies of competing males shapes their relative fitness. Defensive strategies targeting eavesdropping frog-biting midges indirectly shift a male's relative attractiveness to females and predatory bats, though the mechanisms and impacts are context and receiver specific. These findings showcase how the frequency-dependent effects of micropredation can dynamically shape variation in secondary sexual characteristics and thus influence the mechanisms driving sexual selection.

As agriculture continues to expand in tropical regions, effectively preserving biodiversity will rely not only on protected areas but also on sustainable practices within agricultural landscapes. Studying biodiversity changes associated with landscape management is essential for refining practices that support ecosystem resilience and species conservation, but collecting the data required to draw strong conclusions remains challenging because of the high spatial and temporal resolution needed. In this context, passive acoustic monitoring (PAM) offers a valuable solution by enabling researchers to gather continuous, high-resolution biotic signals over time. Using PAM, our objective was to examine how changes in landscape characteristics, specifically heterogeneity and composition, correlate with soundscape patterns including acoustic activity and beta diversity. We collected data across 52 000 ha in the Magdalena River Valley, Colombia, a biodiversity hotspot significantly transformed by palm oil monocultures. We contrasted soundscape data, including acoustic activity and soundscape turnover, with landscape metrics derived from Geographical Information Systems analysed satellite imagery, focusing on landscape composition and configuration. Our analysis showed that compositional and heterogeneity-related landscape variables, such as the proportion of natural cover (NC) and patch shape, were associated with differences in acoustic activity and soundscape homogenization. Specifically, patches with uniform shapes and a lower NC correspond to more homogeneous soundscapes with higher acoustic activity. In contrast, patches with irregular shapes and a higher NC were linked to more heterogeneous soundscapes and lower acoustic activity. By linking soundscape patterns with landscape metrics, we highlight the importance of retaining natural habitat features within productive areas to support acoustic diversity, and by extension, ecological resilience. This article is part of the theme issue ‘Acoustic monitoring for tropical ecology and conservation’.

Most mosquito and midge species use hearing during acoustic mating behaviors. For frog-biting species, however, hearing plays an important role beyond mating as females rely on anuran calls to obtain blood meals. Despite the extensive work examining hearing in mosquito species that use sound in mating contexts, our understanding of how mosquitoes hear frog calls is limited. Here, we directly investigated the mechanisms underlying detection of frog calls by a mosquito species specialized on eavesdropping on anuran mating signals: Uranotaenia lowii. Behavioral, biomechanical and neurophysiological analyses revealed that the antenna of this frog-biting species can detect frog calls by relying on neural and mechanical responses comparable to those of non-frog-biting species. Our findings show that in Ur. lowii, contrary to most species, males do not use sound for mating, but females use hearing to locate their anuran host. We also show that the response of the antennae of this frog-biting species resembles that of the antenna of species that use hearing for mating. Finally, we discuss our data considering how mosquitoes may have evolved the ability to tap into the communication system of frogs.

La bioacústica, o el estudio de los sonidos que producen los animales, es una herramienta que ha sido ampliamente usada en el estudio de las aves, con un incremento en el número de estudios que la aplican en las últimas décadas por su carácter poco invasivo y de relativo bajo costo. Aquí presentamos una revisión sistemática de las investigaciones sobre bioacústica aplicada a la ornitología colombiana en los últimos 22 años, identificando las principales temáticas que se abordan (e.g., taxonomía, inventarios y monitoreos, comportamiento, ecología), y exploramos la historia y el desarrollo de esta herramienta, y su impacto en la ornitología colombiana. Enfatizamos sobre la importancia del estudio evolutivo de la comunicación en aves y su papel en la delimitación e identificación de especies, las técnicas de monitoreo acústico, la ecología del paisaje y urbanización, y esclarecemos algunos aspectos neurobiológicos y de aprendizaje de las vocalizaciones. También destacamos el valor de las colecciones biológicas en el desarrollo de la bioacústica regional y abordamos la problemática de las limitaciones y los sesgos en la investigación científica que han subestimado la importancia de comportamientos poco estudiados como el canto de las hembras. Identificamos que los principales aportes de las investigaciones se centran en las descripciones acústicas y la sistemática. Además, detectamos un incremento en el número de publicaciones en torno a la ecología y el monitoreo acústico. Notamos que la mayoría de los estudios se han realizado sobre aves paseriformes oscines. El reservorio acústico de las aves del país representa más de 1,500 especies y está resguardado en la colección nacional de sonidos y en repositorios públicos. Finalmente, presentamos algunas reflexiones sobre el futuro y la aplicabilidad de esta herramienta en el país para incentivar el fortalecimiento de la bioacústica en el estudio de las aves colombianas y destacamos los enfoques de prioridad para su estudio.

Digital bioacoustic collections preserve important behavioural and ecological traits, as well as trackable evidence of the presence of species in space and time. Well-structured and open-source repositories provide valuable information for science and biodiversity conservation. Here, we introduce the Environmental Sound Collection – ‘Mauricio Álvarez-Rebolledo’ (Colección de Sonidos Ambientales IAvH-CSA) at Instituto Humboldt in Colombia, which is one of the most relevant natural sound repositories in South America. The collection was founded in 1998 as ‘Banco de Sonidos Animales (BSA)’ to document Colombian biodiversity and guide conservation actions, two aims that remain at the forefront of our daily work. After over 25 years, the collection has preserved more than 25,000 audio specimens from over 1,300 species. Here, we highlight the value of sound collections by presenting a historical overview of our collection and providing examples of its role in research and outreach. We also identify taxonomic and geographical gaps that need to be filled, analyse the impact of new technological advances on sound collections, and discuss the critical role of acoustics in the future of research and biodiversity conservation programmes.

Acoustics play an essential role in mosquito communication, particularly during courtship and mating. Mosquito mating occurs in flight and is coordinated by the perception of wingbeat tones. Flight tone frequencies have been shown to mediate sex recognition inAedes,Anopheles,Culex, andToxorhynchitesgenera and are thus a conserved feature of mating across the mosquito family (Culicidae). Upon recognizing a flying female, males respond phonotactically by lunging toward the female and initiating a precopulatory courtship flight interaction. During this interaction, males and females often harmonize their flight tones in a behavior known as harmonic convergence, and male acoustics display rapid frequency modulation. These acoustic phenomena have been characterized both in tethered and free-flying mosquitoes using similar audio recording and analysis methods. Further, the manipulation of mosquito acoustic-related mating behavior shows great promise as a tool for reproductive control strategies. In this brief methodological introduction, we provide an overview of the biological and technical concepts necessary for understanding the recording and analysis of mosquito mating acoustics.