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Bats are typically nocturnal. However, daylight activity (ie between one hour after sunrise and one hour before sunset) is known for a small subset of species, often associated with small oceanic islands with no diurnal avian predators. Here, we describe numerous observations of diurnal activity of Horsfield's bat (Myotis horsfieldii), in Gunung Mulu National Park in Sarawak, Malaysia. Between 2015 and 2020, bats were repetitively observed flying along streams and rivers at 14 localities during various hours of the day. Daylight active bats exhibited a flight pattern concurrent with prey hunting strategies and, through bioacoustics, foraging was confirmed by the presence of feeding buzzes. Despite the occurrence of numerous sympatric avian diurnal predators known to hunt bats (eg bat hawk Macheiramphus alcinus) and avian competitors (eg cave swiftlet Aerodramus spp.), the relatively wide temporal and spatial coverage of the records suggests that diurnal activity of this water-associated bat might be a common phenomenon in the area. We speculate that this atypical behaviour might have arisen to circumvent night-time competition with the high numbers of bats roosting in nearby caves. [ABSTRACT FROM AUTHOR]

Audiovisual collections in traditional private or public institutions are crucial for preserving and safeguarding natural recordings of biodiversity. These archives represent a snapshot of invaluable moments, behaviours, and interactions among species, often representing the last or only existing recordings. Therefore, animal vocalisation recordings are essential for future generations to understand the past and preserve the remaining biodiversity. In this study, we examined the largest Latin American sound archive, the Fonoteca Neotropical Jacques Vielliard, in search for anuran sounds that are not yet formally described. Herein, we describe the calls of eight species, the advertisement call of seven of them, and the release call of two of them. These species, belonging to three different families, were recorded in Brazil over the past six decades and have different conservation status. Notably, two of them are threatened by extinction and one is extinct. Our study fills important knowledge gaps about rare and declining anuran populations, highlighting the value of public scientific audiovisual collections. [ABSTRACT FROM AUTHOR]

n this work, the results of a detailed sound monitoring conducted during December 2023 in the mountain rainforestof Yungas (750 meters above sea level), in the vicinity of Piedras stream within the protected area of Sierra San JavierPark, are presented. The spectrograms obtained from the inner forest differ consistently from those of the riparian forest, distinguishable by their bioacoustic characteristics. It is conjectured that the stream, through its geophonic load and ecological imprint on the landscape, imposes restrictions on the occupation of the ecoacoustic niche by the fauna ensemble present in the area.

Passive acoustic monitoring (PAM) is a powerful tool for studying ecosystems. However, its effective application in tropical environments, particularly for insects, poses distinct challenges. Neotropical katydids produce complex species-specific calls, spanning mere milliseconds to seconds and spread across broad audible and ultrasonic frequencies. However, subtle differences in inter-pulse intervals or central frequencies are often the only discriminatory traits. These extremities, coupled with low source levels and susceptibility to masking by ambient noise, challenge species identification in PAM recordings. This study aimed to develop a deep learning-based solution to automate the recognition of 31 katydid species of interest in a biodiverse Panamanian forest with over 80 katydid species. Besides the innate challenges, our efforts were also encumbered by a limited and imbalanced initial training dataset comprising domain-mismatched recordings. To overcome these, we applied rigorous data engineering, improving input variance through controlled playback re-recordings and by employing physics-based data augmentation techniques, and tuning signal-processing, model and training parameters to produce a custom well-fit solution. Methods developed here are incorporated into Koogu, an open-source Python-based toolbox for developing deep learning-based bioacoustic analysis solutions. The parametric implementations offer a valuable resource, enhancing the capabilities of PAM for studying insects in tropical ecosystems. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'. [ABSTRACT FROM AUTHOR]

Global pollinator decline urgently requires effective methods to assess their trends, distribution and behaviour. Passive acoustics is a non-invasive and cost-efficient monitoring tool increasingly employed for monitoring animal communities. However, insect sounds remain highly unexplored, hindering the application of this technique for pollinators. To overcome this shortfall and support future developments, we recorded and characterized wingbeat sounds of a variety of Iberian domestic and wild bees and tested their relationship with taxonomic, morphological, behavioural and environmental traits at inter- and intra-specific levels. Using directional microphones and machine learning, we shed light on the acoustic signature of bee wingbeat sounds and their potential to be used for species identification and monitoring. Our results revealed that frequency of wingbeat sounds is negatively related with body size and environmental temperature (between-species analysis), while it is positively related with experimentally induced stress conditions (within-individual analysis). We also found a characteristic acoustic signature in the European honeybee that supported automated classification of this bee from a pool of wild bees, paving the way for passive acoustic monitoring of pollinators. Overall, these findings confirm that insect sounds during flight activity can provide insights on individual and species traits, and hence suggest novel and promising applications for this endangered animal group. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'. [ABSTRACT FROM AUTHOR]

Due to rapid technological innovations, the automated monitoring of insect assemblages comes within reach. However, this continuous innovation endangers the methodological continuity needed for calculating reliable biodiversity trends in the future. Maintaining methodological continuity over prolonged periods of time is not trivial, since technology improves, reference libraries grow and both the hard- and software used now may no longer be available in the future. Moreover, because data on many species are collected at the same time, there will be no simple way of calibrating the outputs of old and new devices. To ensure that reliable long-term biodiversity trends can be calculated using the collected data, I make four recommendations: (1) Construct devices to last for decades, and have a five-year overlap period when devices are replaced. (2) Construct new devices to resemble the old ones, especially when some kind of attractant (e.g. light) is used. Keep extremely detailed metadata on collection, detection and identification methods, including attractants, to enable this. (3) Store the raw data (sounds, images, DNA extracts, radar/lidar detections) for future reprocessing with updated classification systems. (4) Enable forward and backward compatibility of the processed data, for example by in-silico data 'degradation' to match the older data quality. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'. [ABSTRACT FROM AUTHOR]

Most birds are characterized by a seasonal phenology closely adapted to local climatic conditions, even in tropical habitats where climatic seasonality is slight. In order to better understand the phenologies of resident tropical birds, and how phenology may differ among species at the same site, we used ~70 000 hours of audio recordings collected continuously for two years at four recording stations in Singapore and nine custom‐made machine learning classifiers to determine the vocal phenology of a panel of nine resident bird species. We detected distinct seasonality in vocal activity in some species but not others. Native forest species sang seasonally. In contrast, species which have had breeding populations in Singapore only for the last few decades exhibited seemingly aseasonal or unpredictable song activity throughout the year. Urbanization and habitat modification over the last 100 years have altered the composition of species in Singapore, which appears to have influenced phenological dynamics in the avian community. It is unclear what is driving the differences in phenology between these two groups of species, but it may be due to either differences in seasonal availability of preferred foods, or because newly established populations may require decades to adjust to local environmental conditions. Our results highlight the ways that anthropogenic habitat modification may disrupt phenological cycles in tropical regions in addition to altering the species community. [ABSTRACT FROM AUTHOR]

The population sizes of manatees in many regions remain largely unknown, primarily due to the challenging nature of conducting visual counts in turbid and inaccessible aquatic environments. Passive acoustic monitoring has shown promise for monitoring manatees in the wild. In this study, we present an innovative approach that leverages a convolutional neural network (CNN) for the detection, isolation and classification of manatee vocalizations from longterm audio recordings. To improve the effectiveness of manatee call detection and classification, the CNN works in two phases. First, a long-term audio recording is divided into smaller windows of 0.5 seconds and a binary decision is made as to whether or not it contains a manatee call. Subsequently, these vocalizations are classified into distinct vocal classes (4 categories), allowing for the separation and analysis of signature calls (squeaks). Signature calls are further subjected to clustering techniques to distinguish the recorded individuals and estimate the population size. The CNN was trained and validated using audio recordings from three different zoological facilities with varying numbers of manatees. Three different clustering methods (community detection with two different classifiers and HDBSCAN) were tested for their suitability. The results demonstrate the ability of the CNN to accurately detect manatee vocalizations and effectively classify the different call categories. In addition, our study demonstrates the feasibility of reliable population size estimation using HDBSCAN as clustering method. The integration of CNN and clustering methods offers a promising way to assess manatee populations in visually challenging and inaccessible regions using autonomous acoustic recording devices. In addition, the ability to differentiate between call categories will allow for ongoing monitoring of important information such as stress, arousal, and calf presence, which will aid in the conservation and management of manatees in critical habitats. [ABSTRACT FROM AUTHOR]

While rhythm can facilitate and enhance many aspects of behavior, its evolutionary trajectory in vocal communication systems remains enigmatic. We can trace evolutionary processes by investigating rhythmic abilities in different species, but research to date has largely focused on songbirds and primates. We present evidence that cetaceans--whales, dolphins, and porpoises--are a missing piece of the puzzle for understanding why rhythm evolved in vocal communication systems. Cetaceans not only produce rhythmic vocalizations but also exhibit behaviors known or thought to play a role in the evolution of different features of rhythm. These behaviors include vocal learning abilities, advanced breathing control, sexually selected vocal displays, prolonged mother-infant bonds, and behavioral synchronization. The untapped comparative potential of cetaceans is further enhanced by high interspecific diversity, which generates natural ranges of vocal and social complexity for investigating various evolutionary hypotheses. We show that rhythm (particularly isochronous rhythm, when sounds are equally spaced in time) is prevalent in cetacean vocalizations but is used in different contexts by baleen and toothed whales. We also highlight key questions and research areas that will enhance understanding of vocal rhythms across taxa. By coupling an infraorder-level taxonomic assessment of vocal rhythm production with comparisons to other species, we illustrate how broadly comparative research can contribute to a more nuanced understanding of the prevalence, evolution, and possible functions of rhythm in animal communication. [ABSTRACT FROM AUTHOR]

In anurans communities, vocalizations play a fundamental role in social interactions, being the most important behavioral modality of communication. Therefore, the description of acoustic signals is indispensable for understanding aspects of their evolutionary history. The Cycloramphus genus consists of 30 species allocated into five groups, of which only 19 have the vocalization described. Cycloramphus lithomimeticus is a small-sized frog belonging to the C. granulosus group. This poorly known species is associated with rock surfaces near waterfalls in Atlantic montane forests, restricted to the state of Rio de Janeiro, southeastern Brazil. Currently, it’s classified as Near Threatened species category of IUCN and many aspects of its natural history remain unknown. Herein, we describe the advertisement call of C. lithomimeticus extending its known geographical distribution and providing additional data on the natural history of the species. We recorded and analyzed 44 calls from 10 males of C. lithomimeticus. The advertisement call of C. lithomimeticus consists of a single pulsed note with 0.3–0.8 sec of duration, emitted sporadically, with an interval between calls of 27.5–226.3 sec, composed by 7–17 pulses emitted at a rate of 18–26/sec, with a peak frequency of 2062.5–3000 Hz. After defining the correspondence between structures for systematic purposes, we made a comparative analysis determined by establishing homology connections with other species of the genus. According to our dominant frequency evolutionary reconstruction, an evolutionary increase in frequency mainly occurred in the C. lithomimeticus species lineage from an ancestral dominant frequency of 1500 Hz of the clade with C. eleutherodactylus species group, C. granulosus species group, and C. fuliginosus species group. This study contributes to our knowledge about the biology of C. lithomimeticus, and our results provide basic data for further acoustic, taxonomic and ecological studies in the genus Cycloramphus. [ABSTRACT FROM AUTHOR]

For over a century, the role of acoustic communication in the sensory ecology of bark beetles (Scolytinae) has been recognized. However, their ‘world of sound’ remains largely unexplored. Here, we review 153 years of bark beetle bioacoustics publications to summarize current knowledge, identify gaps and suggest future research directions. Our survey identified 117 publications covering 170 species. Morphological reports revealed five stridulatory organs across 125 species, with elytro‐tergal, gular‐prosternal and vertex‐pronotum mechanisms being the most prevalent for sound production. However, confirmed sound recordings exist for only 40 species. Acoustic signalling in adults is proposed to function in avoiding enemies, pair formation, sexual selection and spacing, while in juveniles, vibratory communication is proposed for gallery spacing. However, experimental evidence supporting these functions is lacking. Acoustic sensory organs remain unidentified, and comprehension of signal transmission—whether through airborne sounds or solid‐borne vibrations (or both)—is limited. Bioacoustic technologies have emerged as tools for potential management practices and are also discussed. Based on these findings, we recommend three directions for future research: (1) characterize acoustic morphology and behaviours in more species, particularly unrepresented taxa, with recordings in various contexts, preferably under natural conditions; (2) test hypotheses to explain the functions of acoustic communication through experimental and comparative phylogenetic methods and (3) investigate how sounds or vibrations are transmitted and received through behavioural and neurophysiological experiments. Advancements in bark beetle acoustic sensing and communication research will enhance our understanding of their sensory ecology and facilitate potential control measures of these fascinating insects. [ABSTRACT FROM AUTHOR]

Caipirasuchus is a genus of sphagesaurid notosuchian from the Bauru Basin (Upper Cretaceous), southeast Brazil. They were small-sized herbivorous/omnivorous animals, that measured around 1 metre in length, and had a wide diversity and geographical dispersion in the basin. Here, we diagnosed the 6th species of the genus, originating from sandstones of the Adamantina Formation in the municipality of Catanduva, São Paulo State. Caipirasuchus presents a significant variation in the morphology of structures in the choana region. In particular, the new species has chambers in the wings of the pterygoids that connect with an extension of the airways, suggesting a region of resonance used in vocalisation. The different palatal structures in Caipirasuchus may be related to distinct bioacoustic signatures and indicate apossible improvement in the social organisation of Caipirasuchus. [ABSTRACT FROM AUTHOR]

Dolphins are social animals that depend on sound to communicate, navigate, and find food. The aim of our research was to describe dolphin whistle characteristics and compare whistles between two isolated populations of bottlenose dolphins in New Zealand. We focused on three aspects of dolphin bioacoustics (1) classification of whistles; (2) comparison of the whistles of two discrete bottlenose dolphin populations; and (3) comparison of whistles of dolphin populations from around the world. At Great Barrier Island, the most common type of whistle was upsweep followed by sine, while at Doubtful Sound, convex and sine whistles were the most common whistle types. Random Forest models discriminated between whistles from the two populations with an estimated accuracy of 90%. The key differences were whistle-type contour, duration, and end frequency. Linear Mixed models show that whistle acoustic parameters were influenced by location but not by group size or the presence of immatures. Whistle parameters of both populations fell within the range of multiple populations from around the world. This studyprovides a benchmark for future research into drivers of geographic variation in dolphin vocal communication. [ABSTRACT FROM AUTHOR]

Summary: In recent years, the idea has flourished that plants emit and perceive sound and could even be capable of exchanging information through the acoustic channel. While research into plant bioacoustics is still in its infancy, with potentially fascinating discoveries awaiting ahead, here we show that the current knowledge is not conclusive. While plants do emit sounds under biotic and abiotic stresses such as drought, these sounds are high‐pitched, of low intensity, and propagate only to a short distance. Most studies suggesting plant sensitivity to airborne sound actually concern the perception of substrate vibrations from the soil or plant part. In short, while low‐frequency, high‐intensity sounds emitted by a loudspeaker close to the plant seem to have tangible effects on various plant processes such as growth – a finding with possible applications in agriculture – it is unlikely that plants can perceive the sounds they produce, at least over long distances. So far, there is no evidence of plants communicating with each other via the acoustic channel. [ABSTRACT FROM AUTHOR]

Steroid hormones play a pivotal role in shaping arthropod phenotypes, with 20‐hydroxyecdysone (20E) serving as a key regulator of molting, a vulnerable period in an insect's lifecycle. Despite its critical role in arthropod growth and development, the influence of 20E on arthropod behavior, particularly defensive strategies, remains poorly understood. We investigated the impact of 20E on the bioacoustic characteristics of hisses in the Madagascar hissing cockroach (Gromphadorhina portentosa), a social species with multiple complex acoustic signals. With increased 20E, we predicted that hiss production would be more likely and more defensive (i.e., longer hisses with greater intensity (dB) and reduced frequency (Hz)). We injected male G. portentosa with either a low‐ (35 μg) or high‐dose (70 μg) of 20E or a control (0 μg 20E), and we measured the presence/absence of hissing responses and their bioacoustic characteristics following a standardized tactile stimulus. Contrary to our prediction, there was no difference in the likelihood of hissing or hiss duration with 20E administration. However, administering 20E resulted in reduced hiss intensity and increased hiss frequency (as measured by peak and center frequencies), suggesting potential shifts from defensive to aggressive signaling. Our study contributes to the limited knowledge of the behavioral effects of 20E, suggesting that some arthropods may experience increased aggression or energetic limitations to defense during molting. Behavioral changes elicited by hormones have important implications for both fundamental ecology and applied pest management. [ABSTRACT FROM AUTHOR]

Insects play vital ecological roles; many provide essential ecosystem services while others are economically devastating pests and disease vectors. Concerns over insect population declines and expansion have generated a pressing need to effectively monitor insects across broad spatial and temporal scales. A promising approach is bioacoustics, which uses sound to study ecological communities. Despite recent increases in machine learning technologies, the status of emerging automated bioacoustics methods for monitoring insects is not well known, limiting potential applications.To address this gap, we systematically review the effectiveness of automated bioacoustics models over the past four decades, analysing 176 studies that met our inclusion criteria. We describe their strengths and limitations compared to traditional methods and propose productive avenues forward.We found automated bioacoustics models for 302 insect species distributed across nine Orders. Studies used intentional calls (e.g. grasshopper stridulation), by‐products of flight (e.g. bee wingbeats) and indirectly produced sounds (e.g. grain movement) for identification. Pests were the most common study focus, driven largely by weevils and borers moving in dried food and wood. All disease vector studies focused on mosquitoes. A quarter of the studies compared multiple insect families.Our review illustrates that machine learning, and deep learning in particular, are becoming the gold standard for bioacoustics automated modelling approaches. We identified models that could classify hundreds of insect species with over 90% accuracy. Bioacoustics models can be useful for reducing lethal sampling, monitoring phenological patterns within and across days and working in locations or conditions where traditional methods are less effective (e.g. shady, shrubby or remote areas). However, it is important to note that not all insect taxa emit easily detectable sounds, and that sound pollution may impede effective recordings in some environmental contexts.Synthesis and applications: Automated bioacoustics methods can be a useful tool for monitoring insects and addressing pressing ecological and societal questions. Successful applications include assessing insect biodiversity, distribution and behaviour, as well as evaluating the effectiveness of restoration and pest control efforts. We recommend collaborations among ecologists and machine learning experts to increase model use by researchers and practitioners. [ABSTRACT FROM AUTHOR]

Passerines are the most successfully diversified bird order (around 60% of all avian species). They have developed complicated songs to defend their territories and to attract females for mating that can evolve quickly due to cultural transmission. Complex singing as well as plumage coloration of male birds are honest signals for potential partners and provide information about the males' quality. To function as honest signals, both traits must be costly for the males. Of course, not all passerine species are equally clever or beautiful. Even within a single family of 50 to 70 species, relevant traits may vary considerably. Tits and chickadees (Paridae) comprise species of similar size, varying a lot in coloration and plumage pattern. The territorial songs are relatively short and simple. We investigated the relationship between song complexity and plumage coloration, taking phylogenetic relationships into account. We studied 55 out of the 64 species with 1084 song recordings retrieved from an online database. In the best model, besides colorfulness, body size had a negative impact on song complexity. Large colorful species were found to sing less complex songs. This result supports the hypothesis of a trade-off between costly traits and their likely intense signal function. This study contributes to a better understanding of how sexual selection influences the diversification of traits. In addition, we found that despite the relatively uniform size, the general negative correlation between body size and song frequency can be recovered. Some song traits are further influenced by distribution and thus by interspecific differences in climate niche. [ABSTRACT FROM AUTHOR]

Passive acoustic recorders have emerged as powerful tools for ecological monitoring. However, effective monitoring is not simply an act of recording sounds. To have meaning for conservation and management, acoustic monitoring needs to be properly planned and analyzed to yield high quality information. Here, we provide a set of considerations for the design of an effective acoustic monitoring program. We argue that such a program, has the following attributes: (1) has established appropriate partnerships with landowners, Traditional Owners, researchers, or other relevant stakeholders, (2) is based on clear objectives and questions, (3) is explicit in its target sound signals, (4) has considered in‐field sensor placement for a range of factors, including experimental design, statistical power, background noise, and potential impacts on human privacy and animal disturbance, (5) has a justified recording schedule and periodicity, (6) has methods to process sound data in line with objectives, and (7) has protocols for permanent data storage and access. Acoustic monitoring is increasingly used in large‐scale programs and will be important in addressing global biodiversity targets and new biodiversity markets. It is critical that new monitoring programs are designed to effectively and efficiently capture data that address pertinent and emerging issues in conservation. [ABSTRACT FROM AUTHOR]

Species have developed several defensive strategies for survival in response to predation pressures, including chemical, acoustic, visual, and behavioral mechanisms. Anurans serve as prey for numerous species, leading to the evolution of a diverse array of antipredator strategies. Among these strategies, acoustic emission defenses are categorized into distress calls, alarm calls, and warning calls. Although distress calls in frogs have been recognized to occur within the audible spectrum, the occurrence of ultrasound calls has been suggested for one species, but not yet confirmed. Based on our observations, we confirmed the presence of ultrasound distress calls emitted by an adult Haddadus binotatus. The distress call exhibited a high-pitched tone with decreasing frequency modulation and ultrasonic harmonics extending up to approximately 44 kHz. The presence of ultrasound frequencies in distress calls may confer advantages in deterring a broader range of predators. The use of broad-band screams synchronously with other behaviors, as raising the front of the body while arching the back and extreme mouth-gaping, intensified the defensive display, likely being more efficient in deterring predation. We observed similar behavioral repertoire for an adult Ischnocnema cf. henselii. Therefore, it could be widespread across individuals of other Brachycephaloidea genera as well. [ABSTRACT FROM AUTHOR]

Vocal mimicry can develop either through imitation of heterospecific models (primary mimicry) or through imitation of conspecifics already producing mimetic song (secondary mimicry). Distinguishing primary versus secondary mimicry is important from ecological, evolutionary, and neurobiological perspectives. We outline four empirical strategies for researchers to detect the usage of secondary mimicry: (1) model selection strategy (heterospecific model commonly mimicked but rare or absent locally), (2) usage frequency strategy (syllable types commonly mimicked but rarely used by the model), (3) acoustic structure strategy (acoustic divergence in how a syllable type gets produced by mimics versus models), and (4) syntax strategy (consistent variation between mimic and model in the ordering of syllable types). We then use these strategies to produce evidence for secondary mimicry in northern mockingbirds (Mimus polyglottos), focusing mostly on the mimicked songs of northern cardinals (Cardinalis cardinalis) and tufted titmice (Baeolophus bicolor). As further evidence of the mechanisms by which secondary mimicry might occur, we also demonstrate that mockingbirds match countersing much more frequently in response to conspecifics versus heterospecifics. Deeper questions about the precise extent of primary versus secondary mimicry in mockingbirds and other mimicking species still need answers. [ABSTRACT FROM AUTHOR]

Introduction: When studying bird intra- and inter-specific interactions it is crucial to accurately track which individual emits which vocalization. However, locating sounds of free moving birds (and other animals) in nature can be challenging, especially in situations when many individuals call in spatial and temporal vicinity. Methods: In this paper, we will introduce the use of a hand-held acoustic camera which allows solving this problem. The system comprises 64 microphones each sampling a wide angle at a rate of 200kHz. The system can localize up to dozens of nearby callers and it displays them on a visual image. We applied the system to localize and record vocalizations of Arabian babblers (Argya squamiceps) during snake-mobbing behavior to demonstrate its potential. As the recorded babblers are ringed and therefore identifiable, we could use the calling order to analyze the vocalizing mob and to reconstruct a vocal social network depicting which individuals call after which individuals. Results: Acoustic analysis revealed that Arabian babblers call in a periodic pattern and with age specific pause lengths between different individuals. Mobbing events with young babblers display a lower vocal network density compared to only adult groups. Discussion: Our approach demonstrates how this novel technology can be applied to reveal new insight about vocal events in group living wild animals. The approach can be elaborated to study intra- and inter-specific animal vocalizations. [ABSTRACT FROM AUTHOR]

Anurans are among the most vocally active vertebrate animals and emit calls with different functions. In order to attract a mate, during the breeding season male frogs produce mating calls which have species-specific structure and parameters, and have been successfully used to resolve issues in taxonomy and phylogenetic relations. This is particularly useful when closely related taxa are concerned, as many species are morphologically almost identical, but still their status is well-supported by molecular and genetic data, suggesting the existence of mechanisms for reproductive isolation. Such is the case for treefrogs from the Hyla arborea group, which are now recognized as several distinct species. The present study aims to establish differences in call parameters between the European tree frog, Hyla arborea, and the Eastern tree frog, Hyla orientalis, which both occur on the territory of Bulgaria. Using autonomous audio loggers, calls from six sites (three in the range of H. arborea and three in the range of H. orientalis) were recorded between 7 p.m. and 12 a.m. during the breeding season in 2020–2023. The following parameters in a total of 390 mating calls were analyzed: call count, pulse count, call series duration, call period, peak (dominant) frequency, entropy. Results indicated that sites formed two distinct groups, which corresponded to the known distribution ranges of H. arborea and H. orientalis. The first two components of the PCA explained 71% of the total variance, with variables call count, call series duration, peak frequency and entropy being most important for differentiation between the sites. This study presents the first attempt to differentiate between the calls of these two sister taxa, which both fall within the "short-call treefrogs" group, and results are discussed in terms of known data for mating calls in Hyla sp., as well as limitations and future perspectives. [ABSTRACT FROM AUTHOR]

Objective: Once thought to be extirpated from the Chesapeake Bay, fall spawning runs of Atlantic Sturgeon Acipenser oxyrinchus have been rediscovered in the Marshyhope Creek (MC)–Nanticoke River (NR) system of Maryland, United States. High recapture rates in past telemetry surveys suggested a small population in the two connected tributaries. This study aims to generate estimates of abundance and understand within system connectivity for spawning runs in 2020 and 2021. Methods: Data from mobile side‐scan sonar surveys and detections of acoustically tagged adults on stationary telemetry receivers were analyzed in an integrated model to estimate spawning season abundance and examine run timing and system connectivity for this population. An array of acoustic receivers was deployed throughout the MC–NR system to monitor the movement of tagged fish during the spawning run period from mid‐August to late October. Side‐scan sonar surveys were conducted weekly in September in an area of high spawner aggregation to generate count data on spawning run abundance. Result: In 2020 and 2021, 32 (95% credible interval [CRI] = 23–47) and 70 (95% CRI = 49–105) Atlantic Sturgeon, respectively, used the MC–NR system. The lower estimate for 2020 coincided with an earlier end to the spawning run related to cooler September temperatures in that year. Conclusion: In both years, high spawning run connectivity between MC and the upper NR was observed. Overall, run estimates supported previous hypotheses that the MC–NR system supports a very small population and that both MC and the upper NR serve as important areas for spawning activity. Impact statementSturgeon recovery plans require estimates of population abundance. For a small Atlantic Sturgeon population (Chesapeake Bay), this study integrated side‐scan sonar counts with telemetry data to develop spawning run estimates that were quite low: 32 and 70. [ABSTRACT FROM AUTHOR]

Rhodolith beds, recognized as biodiversity hotspots with high ecological and conservation importance, face local anthropic pressures, including trawl fishing. However, monitoring the diversity associated with this sensitive biogenic habitat in the deep waters of the Mediterranean Sea is challenging.Traditional monitoring methods, such as experimental trawling and trammel nets, are extractive and have sampling limitations in providing comprehensive diversity inventories. In this work, we explore three alternative techniques (still video cameras, environmental DNA [eDNA] and bioacoustics) to monitor fish assemblages associated with rhodolith beds in the Menorca Channel at 45–80 m depth.Ten sites were surveyed with eDNA, and 66 fish taxa were identified, including endangered sharks and cryptic species. The molecular operational taxonomic units (MOTUs) richness varied significantly according to habitat heterogeneity, being higher in homogeneous bottoms, and to exposure to trawling, with higher richness in non‐exposed areas.Bioacoustics, though limited by a reduced library of fish sounds, detected differences in sound richness between habitat types, and the highest abundance of sounds was recorded in the areas with the greatest small‐scale habitat heterogeneity.Underwater video revealed limitations in species detection but proved effective for characterizing small‐scale habitat types and heterogeneity.In summary, each technique provides valuable information at different spatial scales and levels of detail. To assess the feasibility of these techniques for long‐term monitoring, we explored their capabilities and limitations in terms of costs, survey logistics and data output. [ABSTRACT FROM AUTHOR]

Wolves howl and dogs bark, both are able to produce variants of either vocalization, but we see a distinct difference in usage between wild and domesticate. Other domesticates also show distinct changes to their vocal output: domestic cats retain meows, a distinctly subadult trait in wildcats. Such differences in acoustic output are well‐known, but the causal mechanisms remain little‐studied. Potential links between domestication and vocal output are intriguing for multiple reasons, and offer a unique opportunity to explore a prominent hypothesis in domestication research: the neural crest/domestication syndrome hypothesis. This hypothesis suggests that in the early stages of domestication, selection for tame individuals decreased neural crest cell (NCCs) proliferation and migration, which led to a downregulation of the sympathetic arousal system, and hence reduced fear and reactive aggression. NCCs are a transitory stem cell population crucial during embryonic development that tie to diverse tissue types and organ systems. One of these neural‐crest derived systems is the larynx, the main vocal source in mammals. We argue that this connection between NCCs and the larynx provides a powerful test of the predictions of the neural crest/domestication syndrome hypothesis, discriminating its predictions from those of other current hypotheses concerning domestication. Research highlights: We outline the developmental link between the larynx and the neural crest. This connection provides a powerful test of the predictions of the most prominent hypothesis in domestication research, the neural crest domestication syndrome hypothesis. [ABSTRACT FROM AUTHOR]

Fin whale song is a ubiquitous low-frequency pulsing that has been recorded in every ocean basin. In recent years, the complexity of fin whale song has been realized. In the North Atlantic, this song is made up of two low-frequency note types (A and B notes) and one higher-frequency note type (upsweeps). The A and B notes are produced with both singlet and doublet inter-note intervals. These song patterns are interwoven throughout an individual's song and have been observed to shift over time, both gradually and suddenly. Like many baleen whales, the population size of fin whales is poorly defined. Passive acoustic monitoring has been suggested as a way to estimate abundance if a cue rate or calling rate can be determined. In this study, we used recordings from 119 fin whale tracks from 2013-2023 generated from passive acoustic recorders in the North Atlantic to define fin whale song patterns in this ocean basin, identify changes in these song patterns over time, and calculate cue rates. The fin whales recorded sang in 4 distinct patterns. Inter-note intervals were 25 s for A-A singlets, 13 s for B-B singlets, 12/20 s for B-B doublets, and 10/11 s for A-B doublets. B-B doublet inter-note intervals significantly increased from May 2019-April 2023 and A-B inter-note intervals showed an intra-annual increasing trend that reset each summer. Fin whale song in the North Atlantic also often includes higher frequency upsweep notes immediately prior to B notes. While A and B note peak frequency was steady over these years, upsweep peak frequency significantly decreased, continuing a similar trend that has been observed over 30 years. Despite these changes, the dominant song pattern remained consistent and cue rate for actively singing whales was relatively stable, which is in contrast to patterns observed in the North Pacific. Many of these nuances in fin whale singing behavior are newly described herein, and these findings are vital for monitoring baseline behavior, behavioral trends over time, and ultimately estimating abundance of a poorly understood species. [ABSTRACT FROM AUTHOR]

This review discusses how welfare scientists can examine vocalizations to gain insight into the affective states of individual animals. In recent years, researchers working in professionally managed settings have recognized the value of monitoring the types, rates, and acoustic structures of calls, which may reflect various aspects of welfare. Fortunately, recent technological advances in the field of bioacoustics allow for vocal activity to be recorded with microphones, hydrophones, and animal-attached devices (e.g., collars), as well as automated call recognition. We consider how vocal behavior can be used as an indicator of affective state, with particular interest in the valence of emotions. While most studies have investigated vocal activity produced in negative contexts (e.g., experiencing pain, social isolation, environmental disturbances), we highlight vocalizations that express positive affective states. For instance, some species produce vocalizations while foraging, playing, engaging in grooming, or interacting affiliatively with conspecifics. This review provides an overview of the evidence that exists for the construct validity of vocal indicators of affective state in non-human mammals. Furthermore, we discuss non-invasive methods that can be utilized to investigate vocal behavior, as well as potential limitations to this line of research. In the future, welfare scientists should attempt to identify reliable, valid species-specific calls that reflect emotional valence, which may be possible by adopting a dimensional approach. The dimensional approach considers both arousal and valence by comparing vocalizations emitted in negative and positive contexts. Ultimately, acoustic activity can be tracked continuously to detect shifts in welfare status or to evaluate the impact of animal transfers, introductions, and changes to the husbandry routine or environment. We encourage welfare scientists to expand their welfare monitoring toolkits by combining vocal activity with other behavioral measures and physiological biomarkers. [ABSTRACT FROM AUTHOR]

Passive acoustic monitoring (PAM) studies generate thousands of hours of audio, which may be used to monitor specific animal populations, conduct broad biodiversity surveys, detect threats such as poachers, and more. Machine learning classifiers for species identification are increasingly being used to process the vast amount of audio generated by bioacoustic surveys, expediting analysis and increasing the utility of PAM as a management tool. In common practice, a threshold is applied to classifier output scores, and scores above the threshold are aggregated into a detection count. The choice of threshold produces biased counts of vocalizations, which are subject to false positive/ negative rates that may vary across subsets of the dataset. In this work, we advocate for directly estimating call density: The proportion of detection windows containing the target vocalization, regardless of classifier score. We propose a validation scheme for estimating call density in a body of data and obtain, through Bayesian reasoning, probability distributions of confidence scores for both the positive and negative classes. We use these distributions to predict site-level call densities, which may be subject to distribution shifts (when the defining characteristics of the data distribution change). These methods may be applied to the outputs of any binary detection classifier operating on fixedsize audio input windows. We test our proposed methods on a real-world study of Hawaiian birds and provide simulation results leveraging existing fully annotated datasets, demonstrating robustness to variations in call density and classifier model quality. [ABSTRACT FROM AUTHOR]

Bats play a pivotal role in maintaining ecological balance, and studying their behaviors offers vital insights into environmental health and aids in conservation efforts. Determining the presence of various bat species in an environment is essential for many bat studies. Specialized audio sensors can be used to record bat echolocation calls that can then be used to identify bat species. However, the complexity of bat calls presents a significant challenge, necessitating expert analysis and extensive time for accurate interpretation. Recent advances in neural networks can help identify bat species automatically from their echolocation calls. Such neural networks can be integrated into a complete end-to-end system that leverages recent internet of things (IoT) technologies with long-range, low-powered communication protocols to implement automated acoustical monitoring. This paper presents the design and implementation of such a system that uses a tiny neural network for interpreting sensor data derived from bat echolocation signals. A highly compact convolutional neural network (CNN) model was developed that demonstrated excellent performance in bat species identification, achieving an F1-score of 0.9578 and an accuracy rate of 97.5%. The neural network was deployed, and its performance was evaluated on various alternative edge devices, including the NVIDIA Jetson Nano and Google Coral. [ABSTRACT FROM AUTHOR]

We present a high-resolution, densely sampled data set of wild bird songs collected over multiple years from a single population of great tits, Parus major , in the U.K. The data set includes over 1 100 000 individual acoustic units from 109 963 richly annotated songs, sung by more than 400 individual birds, and provides unprecedented detail on the vocal behaviour of wild birds. Here, we describe the data collection and processing procedures and provide a summary of the data. We also discuss potential research questions that can be addressed using this data set, including behavioural repeatability and stability, links between vocal performance and reproductive success, the timing of song production, syntactic organization of song production and song learning in the wild. We have made the data set and associated software tools publicly available with the aim that other researchers can benefit from this resource and use it to further our understanding of bird vocal behaviour in the wild. • We present a large data set of songs from a wild population of great tits. • It contains 1.1 M acoustic units from 109 K songs recorded over several years. • It includes extensive metadata and annotations. • The data set and associated software tools are publicly available. [ABSTRACT FROM AUTHOR]

We describe a new frog species that is the sibling of Pristimantis reichlei. These two sister species inhabit the Amazonian lowlands and adjacent foothills of the Andes, from central Bolivia to central Peru. Pristimantis reichlei occurs from central Bolivia to southern Peru (Alto Purús National Park), while the new species occurs from northern Bolivia (Departamento Pando) to Panguana in central Peru (Departamento Huánuco), at elevations between 220 and 470 m a.s.l. In spite of their morphological crypsis, these siblings occur in syntopy without evidence of interbreeding (in the Alto Purús area) and are recovered as reciprocally monophyletic. Their uncorrected pairwise genetic distances in the 16S rRNA gene range from 9.5–13.5%, and their advertisement calls differ in both qualitative and quantitative traits. Moreover, our study found uncorrected pairwise distances within the new species of up to 5.0% and up to 9.3% within P. reichlei. We therefore cannot rule out the possible existence of hybrids or additional species-level lineages hidden in this complex. Furthermore, we found another potential pair of sibling species composed of P. danae and an unnamed lineage, with divergences of 9.4% in the 16S gene, whose in-depth analysis and taxonomic treatment are pending future revision. With the new nominal species, the Pristimantis danae species group now includes 20 species, distributed across the upper Amazon basin and in the eastern Andes, from western Brazil to Bolivia and Peru. Our study, together with an increasing number of other studies, indicates that sibling species are far from being rare among Amazonian amphibians and that species resolution remains low even for groups that have received considerable attention in recent years. [ABSTRACT FROM AUTHOR]

Monitoring biodiversity changes associated with ecological restoration is crucial in the current UN Decade on Restoration. Although several studies highlight the impacts of restoration on ecosystems, it is also important to understand how restoration alters species' behavior, including vocalization. Advances in conservation technology, such as passive acoustic monitoring, facilitate rapid and noninvasive monitoring. In this study, we quantified changes in the vocal behavior of a bird species in response to small‐scale restoration carried out by removing the invasive shrub, Lantana camara (lantana), in a Central Indian tropical dry forest. We examined associations between sites of varying lantana densities and the vocalization of one of its primary dispersers, red‐vented bulbul (RVBU). We found statistically significant differences in note‐length and bandwidth of RVBU vocalizations across sites. A random forest classification model showed that Lantana density was not an important predictor of RVBU vocalizations. Apart from the percentage of forest area and farms in our sites, total human population was the most important predictor for RVBU vocalizations suggesting RVBU's use of human habitations as possible resource hubs. Our findings suggest that lantana removal is not associated with significant changes in RVBU vocalization. This study provides empirical evidence that ecological restoration may not alter species' vocalization in the short term and highlights the importance of moving beyond species presence and understanding the impact of restoration on species behavior. [ABSTRACT FROM AUTHOR]

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Navigation through dense foliage presents a fundamental challenge to autonomous systems, and achieving a performance level similar to echolocating bats could have important applications in areas such as forestry and farming. However, the clutter echoes originating from such environments have been difficult to analyze. To study the problem of sonar‐based navigation in dense foliage in simulation, an artificial generation system for leaf impulse responses (IRs) based on variational auto‐encoders is proposed. The system is to aid the construction of artificial foliage echo environments. A dataset of leaf echoes was collected in an anechoic chamber and convolved with the original signal to estimate the IR of each leaf. A modified version of the conditional variational autoencoder ‐ generative adversarial network (cVAE‐GAN) architecture was trained successfully on this dataset to produce a generative model that was conditional on leaf viewing angles, size, and species. The IRs generated by the model capture quantitative and qualitative similarity to the measured IRs. It surpasses the previous state of the art foliage echo model based on reflecting disks. The model's computational efficiency and its success suggest its potential use for simulating large environments of foliage to study bat biosonar and aid in engineering biomimetic sonar devices. [ABSTRACT FROM AUTHOR]

Female advertisement of reproductive state and receptivity has the potential to play a large role in the mating systems of many taxa, but investigations of this phenomenon are underrepresented in the literature. North American red squirrels (Tamiasciurus hudsonicus) are highly territorial and engage in scramble competition mating, with males converging from spatially disparate territories to engage in mating chases. Given the narrow estrus window exhibited in this species, the ubiquitous use of vocalizations to advertise territory ownership, and the high synchronicity of males arriving from distant territories, we hypothesized that female vocalizations contain cues relating to their estrous state. To test this hypothesis, we examined the spectral and temporal properties of female territorial rattle vocalizations collected from females of known reproductive condition over 3 years. While we found no distinct changes associated with estrus specifically, we did identify significant changes in the spectral characteristics of rattles relating to both female body mass and reproductive state relative to parturition. To the best of our knowledge, this is the first evidence of changes in vocal characteristics associated with late pregnancy in a nonhuman mammal. [ABSTRACT FROM AUTHOR]

Machine learning tools are widely used in support of bioacoustics studies, and there are numerous publications on the applicability of convolutional neural networks (CNNs) to the automated presenceabsence detection of species. However, the relation between the merit of acoustic background modelling and the recognition performance needs to be better understood. In this study, we investigated the influence of acoustic background substance on the performance of the acoustic detector of the White-lored Spinetail (Synallaxis albilora). Two detector designs were evaluated: the 152- layer ResNet with transfer learning and a purposely created CNN. We experimented with acoustic background representations trained with season-specific (dry, wet, and all-season) data and without explicit modelling to evaluate its influence on the detection performance. The detector permits monitoring of the diel behaviour and breeding time of White-lored Spinetail solely based on the changes in the vocal activity patterns. We report an advantageous performance when background modelling is used, precisely when trained with all-season data. The highest classification accuracy (84.5%) was observed for the purposely created CNN model. Our findings contribute to an improved understanding of the importance of acoustic background modelling, which is essential for increasing the performance of CNN-based species detectors. [ABSTRACT FROM AUTHOR]

The ongoing biodiversity crisis, driven by factors such as land-use change and global warming, emphasizes the need for effective ecological monitoring methods. Acoustic monitoring of biodiversity has emerged as an important monitoring tool. Detecting human voices in soundscape monitoring projects is useful both for analyzing human disturbance and for privacy filtering. Despite significant strides in deep learning in recent years, the deployment of large neural networks on compact devices poses challenges due to memory and latency constraints. Our approach focuses on leveraging knowledge distillation techniques to design efficient, lightweight student models for speech detection in bioacoustics. In particular, we employed the MobileNetV3-Small-Pi model to create compact yet effective student architectures to compare against the larger EcoVAD teacher model, a well-regarded voice detection architecture in eco-acoustic monitoring. The comparative analysis included examining various configurations of the MobileNetV3-Small-Pi-derived student models to identify optimal performance. Additionally, a thorough evaluation of different distillation techniques was conducted to ascertain the most effective method for model selection. Our findings revealed that the distilled models exhibited comparable performance to the EcoVAD teacher model, indicating a promising approach to overcoming computational barriers for real-time ecological monitoring. [ABSTRACT FROM AUTHOR]

Previous work has demonstrated that there is extensive variation in the songs of White-crowned Sparrow (Zonotrichia leucophrys) throughout the species range, including between neighboring (and genetically distinct) subspecies Z. l. nuttalli and Z. l. pugetensis. Using a machine learning approach to bioacoustic analysis, we demonstrate that variation in song is correlated with year of recording (representing cultural drift), geographic distance, and climatic differences, but the response is subspecies- and season-specific. Automated machine learning methods of bird song annotation can process large datasets more efficiently, allowing us to examine 1,913 recordings across ~60 years. We utilize a recently published artificial neural network to automatically annotate White-crowned Sparrow vocalizations. By analyzing differences in syllable usage and composition, we recapitulate the known pattern where Z. l. nuttalli and Z. l. pugetensis have significantly different songs. Our results are consistent with the interpretation that these differences are caused by the changes in characteristics of syllables in the White-crowned Sparrow repertoire. This supports the hypothesis that the evolution of vocalization behavior is affected by the environment, in addition to population structure. [ABSTRACT FROM AUTHOR]

Fish bioacoustics, or the study of fish hearing, sound production, and acoustic communication, was discussed as early as Aristotle. However, questions about how fishes hear were not really addressed until the early 20th century. Work on fish bioacoustics grew after World War II and considerably in the 21st century since investigators, regulators, and others realized that anthropogenic (human-generated sounds), which had primarily been of interest to workers on marine mammals, was likely to have a major impact on fishes (as well as on aquatic invertebrates). Moreover, passive acoustic monitoring of fishes, recording fish sounds in the field, has blossomed as a noninvasive technique for sampling abundance, distribution, and reproduction of various sonic fishes. The field is vital since fishes and aquatic invertebrates make up a major portion of the protein eaten by a signification portion of humans. To help better understand fish bioacoustics and engage it with issues of anthropogenic sound, this special issue of The Journal of the Acoustical Society of America (JASA) brings together papers that explore the breadth of the topic, from a historical perspective to the latest findings on the impact of anthropogenic sounds on fishes. [ABSTRACT FROM AUTHOR]

Modification of ecosystems as a consequence of urbanisation alters natural habitat structures and soundscapes, creating constraints for vocal communication in animals. Birds are able to adjust their vocalisation to the prevailing acoustic features of their habitat. As such, their sounds have been shown to reflect the level of anthropogenic disturbances across landscapes. While the effect of a single anthropogenic disturbance like ambient noise on birds' vocal communication is widely investigated, the combined effects of various disturbances remain less explored. We tested single and combined effects of anthropogenic noise and urban physical structures on the vocalisations of two African passerines, the Common Bulbul Pycnonotus barbatus and Northern Grey-headed Sparrow Passer griseus. We predicted that (i) both species would increase the minimum frequency of their vocalisation to avoid masking by ambient noise, (ii) both species would decrease their maximum frequency to evade distortion by physical structures, (iii) the two urban components would have a significant combined effect on the vocalisations, and (iv) the change in minimum or maximum frequency will lead to a corresponding change in the vocalisation bandwidth. For the Common Bulbul, the minimum frequency increased significantly as the ambient noise level increased, but the maximum frequency did not change in response to urban physical structures. For the Northern Grey-headed Sparrow, the minimum frequency did not show a response to ambient noise, but the maximum frequency decreased significantly as physical structures and ambient noise increased. We did not find any evidence for a combined effect of urban physical structures and ambient noise on the vocal adjustment of either species. A change in either the minimum or maximum frequency resulted in a corresponding change in the vocalisation bandwidth of each species. Our findings highlight how the same vocalisation traits of different songbird species can be affected differently by novel selective pressures in acoustic communication that arise in urban environments. [ABSTRACT FROM AUTHOR]

The source-filter theory suggests that animal traits, such as body size, are reliably encoded in vocalizations. These vocal signals, with a likely precopulatory function, are thought to be costly; given energetic constraints, they are expected to be in a trade-off with postcopulatory traits, such as testicular volume. Although this trade-off has been generally tested through comparative studies across species, it remains understudied whether it holds within a single species. Using parallel-laser photogrammetry, we conducted a 9-month study at Palenque National Park, Mexico, to investigate whether fundamental frequency (F0) or formant dispersion (ΔF) of roars and barks from 14 male black howler monkeys encode cues of body size, and whether they are in a trade-off with testicular volume. We found that only roar ΔF was associated with body size, with larger males producing roars with lower ΔF, suggesting a likely use of roars in male–male competition or female mate choice in black howlers. In contrast, after accounting for the positive effect of body size on testicular volume, no association was found between these vocal features and testicular volume. Our results show the presence of acoustic allometry within roars of male black howlers and suggest the absence of a trade-off within a single species, despite its presence at the genus level. • Roar formant dispersion was an honest signal of body size in adult male black howlers. • Formant dispersion, not fundamental frequency, correlated negatively with body size. • Barks did not contain information about adult male body size. • Testicular volume was not correlated with acoustic features of roars or barks. • Vocal–testicular trade-off reported across howler species was absent in black howlers. [ABSTRACT FROM AUTHOR]

Despite a relatively broad distribution in Africa, the Spotted Rubber Frog, Phrynomantis affinis, is extremely rarely encountered. Only 18 specimens from 12 localities have been collected with a few additional observations recorded. Virtually nothing of the species' natural history is known. We report or summarise new localities and range extensions of P. affinis in Namibia and Zambia and describe the call for the first time. We also compare its call to that of the sister species, P. bifasciatus, describing this call for the first time and noting a considerable range extension. The calls show several key differences, with P. affinis calls generally having a lower dominant frequency, pulse repetition rate, and number of pulses than P. bifasciatus. The calls of Namibian and Zambian P. affinis also show marked differences. These descriptions add valuable natural history information for both species and will considerably improve the field detection of the enigmatic P. affinis. [ABSTRACT FROM AUTHOR]

thebeat is a Python package for working with temporal sequences and rhythms in the behavioral and cognitive sciences, as well as in bioacoustics. It provides functionality for creating experimental stimuli, and for visualizing and analyzing temporal data. Sequences, sounds, and experimental trials can be generated using single lines of code. thebeat contains functions for calculating common rhythmic measures, such as interval ratios, and for producing plots, such as circular histograms. thebeat saves researchers time when creating experiments, and provides the first steps in collecting widely accepted methods for use in timing research. thebeat is an open-source, on-going, and collaborative project, and can be extended for use in specialized subfields. thebeat integrates easily with the existing Python ecosystem, allowing one to combine our tested code with custom-made scripts. The package was specifically designed to be useful for both skilled and novice programmers. thebeat provides a foundation for working with temporal sequences onto which additional functionality can be built. This combination of specificity and plasticity should facilitate research in multiple research contexts and fields of study. [ABSTRACT FROM AUTHOR]

Despite the high diversity of bats in neotropics, traditional methods such as mist nets, harp traps and roost detection have limitations in capturing that diversity in a landscape, with most detected species restricted to those that forage in the undergrowth or enclosed spaces. Therefore, acoustic records become a tool that complements and enhances the efforts to get more complete bat inventories while avoiding alterations in usual foraging activities and disruption in their life cycles. This study describes the acoustic parameters (spectral and temporal variables) of the echolocation pulses of insectivorous bats to characterise different species of bats in Southwest Colombia acoustically. We recorded echolocation calls between December 2017 and May 2020 in the Andean and Pacific regions of the Department of Nariño. We analysed 81 sequences of echolocation calls from eight bat species belonging to three families: Vespertilionidae, Molossidae and Emballonuridae. We perform recordings on free-flying bats with identity corroboration by capture for recording in flight rooms and examination in the hand. Myotis riparius and Lasiurus blossevillii were recorded for the first time in the Nariño Department. M. albescens, M. keaysi, M. riparius and L. blossevillii (Vespertilionidae) had pulses of frequency modulated (FM) with a quasi-constant frequency (QCF) ending; Molossus molossus, Tadarida brasiliensis and Promops centralis (Molossidae) had pulses with constant frequency (CF) and QCF; and Saccopteryx bilineata (Emballonuridae) had pulses with QCF. This study contributes to the efforts to facilitate the identification of insectivorous bats of the Neotropics using the acoustic monitoring approaches, represents a reference to compare the acoustic studies in Southwestern Colombia and contributes to increasing our knowledge of the bat diversity in the region. [ABSTRACT FROM AUTHOR]

Biofinish is an innovative wood protection system inspired by biological processes. It enhances the hydrophobicity of wood through oil treatment, resulting in improved dimensional stability. Living cells of the fungus Aureobasidium pullulans effectively protect wood from deterioration caused by other decaying fungi. The melanin pigment produced by the fungus provides an appealing dark surface and additionally protects the wood substrate against UV radiation. The significant advantage of Biofinish is its remarkable self-healing ability, which distinguishes it from conventional wood protection methods. This research aimed to explore fungal species colonising surfaces exposed to natural weathering and assess the survival of A. pullulans on wood surfaces coated with Biofinish during its in-service period. This study was performed on a facade composed of European larch wood (Larix decidua) treated with linseed oil and coated with Biofinish at the InnoRenew CoE building in Izola, Slovenia, following a 9-month exposure period. The majority of the detected species belonged to the genera Aureobasidium. The results indicated the survival and effective antagonistic action of A. pullulans, the living and active ingredient of the coating, against other wood-decaying fungi. [ABSTRACT FROM AUTHOR]

Anuran communication is largely based on acoustic signals, but different sensory modes are also widespread, including visual communication using body color traits as a way of signaling. The Brazilian treefrog, Boana albomarginata, has a complex behavioral repertoire presenting several call types and performing gestures as visual signals. This species has a greenish body color with orange patches on the flanks and thighs. These patches become visible when males are in a calling posture or performing visual signals such as leg kicking and limb lifting, suggesting that they might use the patches as visual cues. We sampled seven populations, using call recordings and photographs to access males call and color traits. We demonstrate that there is variation in color and call properties across populations. Additionally, we observe variation in the relationship between color traits and call properties in different populations, revealing that only two populations exhibit a significant correlation between color and call traits. Further, while call properties and color traits were not related with individual body size, they were associated with body condition. The results indicate a universal pattern across populations for call properties, wherein males in better condition consistently displayed lower-pitched calls, longer calls, and shorter intervals between calls. Regarding color traits, males in better condition in four out of the seven evaluated populations exhibited larger orange patch sizes, lower orange hue values, and higher hue contrasts. Although we observed some level of relation among color, call, and body traits, there is not a universal pattern across all populations. Significance statement: Animal social interactions are mediated by signals transmitted through different sensory modes (i.e., acoustic, chemical, tactile, and visual), and more than one of these modalities can compose the behavioral repertoire of one species. Using photographs and acoustic recordings of Boana albomarginata males in natural environments, we documented geographic variation in both signals, call and color, and investigated their potential to convey individual body size and condition. Our findings reveal that both signals were correlated with individual body condition. In addition, color traits were associated with call properties in some populations. [ABSTRACT FROM AUTHOR]