Biology subjects

Araya-Salas, M.

Publications and source records attributed to Araya-Salas, M..

4 recordsLinked to original sources

bioRxiv2023

Variation in echolocation call emission of Neotropical insect-eating bats in response to shifting ambient temperatures

The sensory systems of animals are essential for them to respond to environmental cues and signals. However, their functionality might be altered by climate change. Most bats, for example, rely on acoustic signal emission for acquiring food, but their high-frequency echolocation calls are strongly attenuated in the air. Attenuation in air changes with changing weather conditions, which can lead to shifts in echo-based prey detection distance. However, bats adjust call parameters to the task and environment, and this behavioural plasticity may also help them to counteract potential increases in sound attenuation to keep echo detectability constant. We explored this ability in a community of insectivorous bats in a montane forest of Costa Rica. We recorded bat echolocation calls in response to experimentally increased temperatures, simulating intermediate and arguably realistic projected climate change scenarios. We calculated atmospheric attenuation and detection distance for each temperature and echolocation call. We found some changes in source level and call duration, yet not in peak frequency, and responses were not consistent across species with increasing atmospheric attenuation. This might be explained by several non-mutually exclusive reasons, including that the experimental increase in temperature and change of atmospheric attenuation were not sufficient to affect close-range prey detection. Ultimately, this study contributes to our understanding of sensory system adaptation under the pressure imposed by climate change. SUMMARY STATEMENTStudying adjustments in bats call parameters can reveal responses to the pressure imposed by climate change.

ecology↗

bioRxiv2023

baRulho: an R package to quantify degradation in animal acoustic signals

O_LIAnimal acoustic signals are shaped by selection to convey information based on their tempo, intensity, and frequency. However, sound degrades as it propagates over space and across physical obstacles (e.g., vegetation or infrastructure), which affects communication potential. Therefore, transmission experiments are designed to quantify change in signal structure in a given habitat by broadcasting and re-recording animal sounds at increasing distances. C_LIO_LIWe introduce baRulho, an R package designed to simplify the implementation of sound transmission experiments. We highlight the package features with a case study testing the effects of habitat and acoustic structure on signal transmission. Synthesized sounds that varied in frequency, duration, and frequency and amplitude modulation were broadcast and re-recorded at five increasing distances in open and closed understory at the Bosque de Tlalpan, Mexico City. With this data, we showcase baRulhos functions to prepare master sound files, annotate re-recorded test sounds, as well as to calculate and visualize measures that quantify degradation of acoustic signals in the time and frequency domain. C_LIO_LIDegradation measures in baRulho adequately quantified acoustic degradation, following predicted patterns of sound transmission in natural environments. Re-recorded signals degraded less in open habitats compared to closed habitats, with higher-frequency sounds exhibiting more degradation. Furthermore, frequency modulated sounds degraded to a greater extent than pure tones. The increased attenuation and reverberation observed in higher frequency sounds and closed habitats suggest that factors such as absorption and scattering by vegetation play significant roles in transmission patterns. C_LIO_LIThe R package baRulho provides an open-source, user-friendly suite of tools designed to facilitate analysis of animal sound degradation. Notably, it offers similar results to other sound analysis software but with significantly reduced processing time. Moreover, the package minimizes the potential for user error through automated test file annotation and verification procedures. We hope that baRulho can help enhance accessibility to transmission experiments within the research community, ultimately contributing to a deeper understanding of the ecological drivers of animal communication systems. C_LI

evolutionary biology↗

bioRxiv2022

ohun: an R package for diagnosing and optimizing automatic sound event detection

Animal acoustic signals are widely used in diverse research areas due to the relative ease with which sounds can be registered across a wide range of taxonomic groups and research settings. However, bioacoustics research can quickly generate large data sets, which might prove challenging to analyze promptly. Although many tools are available for the automated detection of sounds, choosing the right approach can be difficult only a few tools provide a framework for evaluating detection performance. Here we present ohun, an R package intended to facilitate automated sound detection. ohun provides functions to diagnose and optimize detection routines and compare performance among different detection approaches. The package uses reference annotations containing the time position of target sounds in a training data set to evaluate detection routines performance using common signal detection theory indices. This can be done both with routine outputs imported from other software and detections run within the package. The package also provides functions to organize acoustic data sets in a format amenable to detection analyses. ohun also includes energy-based and template-based detection methods, two commonly used automatic approaches in bioacoustic research. We show how ohun automatically can be used to detect vocal signals with case studies of adult male zebra finch (Taenopygia gutata) songs and Spixs disc-winged bat (Thyroptera tricolor) ultrasonic social calls. We also include examples of how to evaluate the detection performance of ohun and external software. Finally, we provide some general suggestions to improve detection performance.

ecology↗

bioRxiv2022

Landing manoeuvres predict roost-site preferences in bats

Roosts are vital for the survival of many species, and how individuals choose one site over another is affected by various ecological factors. Biomechanical constraints could also affect roost selection, particularly in volant taxa that require sites with easy access, thereby reducing costs (i.e., predation, accidents). To date, no studies have established an association between landing performance and roost-site selection, as predicted by biomechanical constraints associated with flight. We aim to determine roost-site selection in disc-winged bats (Thyroptera tricolor), a species known to roost within developing tubular leaves. This study is coupled with various experiments that measure how a conspicuous apex affects landing tactics and performance. We show that T. tricolor prefers leaves with a longer apex, the space typically used for landing. Bats also approach and enter these leaves more consistently, increasing task performance while reducing the risk of injuries. Summary statementSpixs disc-winged bats prefer to roost in some types of leaves, which we show may be related to costly maneuvers during the approach and landing phases.

ecology↗