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Simple Summary: Detecting animal key points and poses is crucial for recognizing behaviors and protecting species. Traditional methods based on images face challenges like limited training data and the need for extensive manual annotations. To address this, we utilized a language–image contrastive learning model that learns the relationship between text and images, developing a new approach for animal pose estimation that combines textual descriptions and visual data. Our experiments on the AP10K dataset, a benchmark for animal pose estimation with over 10,000 images of 23 species, showed this method to be more accurate than image-based techniques. Traditional animal pose estimation techniques based on images face significant hurdles, including scarce training data, costly data annotation, and challenges posed by non-rigid deformation. Addressing these issues, we proposed dynamic conditional prompts for the prior knowledge of animal poses in language modalities. Then, we utilized a multimodal (language–image) collaborative training and contrastive learning model to estimate animal poses. Our method leverages text prompt templates and image feature conditional tokens to construct dynamic conditional prompts that integrate rich linguistic prior knowledge in depth. The text prompts highlight key points and relevant descriptions of animal poses, enhancing their representation in the learning process. Meanwhile, transformed via a fully connected non-linear network, image feature conditional tokens efficiently embed the image features into these prompts. The resultant context vector, derived from the fusion of the text prompt template and the image feature conditional token, generates a dynamic conditional prompt for each input sample. By utilizing a contrastive language–image pre-training model, our approach effectively synchronizes and strengthens the training interactions between image and text features, resulting in an improvement to the precision of key-point localization and overall animal pose estimation accuracy. The experimental results show that language–image contrastive learning based on dynamic conditional prompts enhances the average accuracy of animal pose estimation on the AP-10K and Animal Pose datasets. [ABSTRACT FROM AUTHOR]

Background: Although the issue of high mental health burden among veterinarians is well-documented in previous studies, little is known about the specific occupational stress factors associated with mental health issues. Therefore, the aims of this study were twofold: (1) to assess occupational stress factors within the veterinary profession, with a particular emphasis on comparing the expectations of veterinary students with the experiences of practicing veterinarians and (2) to link the experienced stress with mental health indicators in veterinarians. Methods: All registered veterinarians and veterinary-medicine students in Austria were invited to participate in a cross-sectional online survey. The data collection took place during the winter of 2022/2023 and included standardized questionnaires on mental well-being (WHO-5), depression (PHQ-9), anxiety (GAD-7), stress (PSS-4), and insomnia (ISI-2). Additionally, participants were asked about various estimated (students) or experienced (vets) occupational stress factors, which were to be rated on a 5-point Likert scale ranging from "not at all" to "very strongly". An open question invited respondents to identify in free text further experienced/anticipated sources of work-related stressors in veterinary practice. Results: A total of 430 students and 440 veterinarians participated in the study. The results of a repeated measures analysis of variance (ANOVA) indicate that the burden of bureaucracy is perceived as less stressful by students than experienced by veterinarians, all other areas are perceived as more stressful by students than by veterinarians. In veterinarians, bureaucracy is experienced as the most burdensome, followed by animal suffering, and communication with animal owners. Further analysis of possible associations between the extent of perceived stressors and indicators of mental health shows that while bureaucracy is the most burdensome, it has the smallest correlation with mental health indicators. On the other hand, financial concerns, which are not ranked among the main stressors, have the strongest correlation with impaired mental health. Conclusion: The results suggest that financial security for veterinarians is crucial to safeguard their mental health. The training of veterinary medicine students and practicing veterinarians in the areas of administration, time management, handling animal suffering, and communication with animal owners might be beneficial in reducing their job-related stressors. [ABSTRACT FROM AUTHOR]

There is a long-standing debate about experimental non-human animals and animal-free methods in scientific research. Among the various stakeholders involved in the debate are the scientists. During media broadcasts we, animal researchers and animal-free methods researchers, were positioned as 'opponents'. In this essay we describe our initial rational thoughts and emotions after these events, and how we came together to explore our common ground on animal(-free) experimentation. Realizing that all models have advantages and limitations, our common ground lies in the principles of good scientific research and responsible experimentation. Our communication emanating from the broadcasts has been instrumental in improving communication on animal(-free) experimentation issues by teaming up. We strongly believe that this is essential for making well-informed decisions for the methods we are using now and will be using in the future. [ABSTRACT FROM AUTHOR]

Erving Goffman is one of sociology's most influential thinkers. Scholars debate the extent to which he worked in competing theoretical traditions (e.g., interactionist or structuralist), yet few acknowledge his intellectual indebtedness to animal ethology. This article traces how naturalistic studies of paralinguistic animal communication influenced Goffman's corpus and specifies the ideas he built on from that field, especially territoriality and ritualized display. Goffman's comparative approach to animal and human interaction reveals the shortcomings of sociologists' lingua-centric approach to interaction; elevates animals to social actors, capable of metacommunication, reading others' intentions, and adjusting their behavior accordingly; and humbles humans, who he finds enacting rituals of civility for the same reason animals engage in ritualized display: to manage threats and facilitate bonding. Goffman's thesis on the similarities between animal and human social behavior compels sociology to consider animal studies, and his use of ethology helps reconcile his interactionist and Durkheimian tendencies. [ABSTRACT FROM AUTHOR]

Professor Wolfgang Wickler, a highly respected and knowledgeable scientist, passed away on January 12, 2024. He made significant contributions to the field of ethology, particularly in the areas of animal behavior and evolutionary biology. Throughout his career, he emphasized comparative work and conducted extensive field research in Africa and other locations. Professor Wickler was also known for his leadership skills and his ability to foster independent research among his students and colleagues. He published numerous articles and books, both for scientific audiences and the general public, and was dedicated to sharing the insights of ethology with a wider audience. His impact on the field of ethology and his dedication to scientific excellence will be greatly missed. [Extracted from the article]

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]

This paper proposes a typology of compositionality as manifest in human language and animal communication. At the heart of the typology is a distinction between bare compositionality, in which the meaning of a complex expression is determined solely by the meanings of its constituents, and constructional compositionality, in which the meaning of a complex expression is determined by the meanings of its constituents and also by various aspects of its structure. Bare and constructional compositionality may be observed in human language as well as in various animal communication systems, including primates and birds. Architecturally, bare compositionality provides the foundations for constructional compositionality, while phylogenetically, bare compositionality is a potential starting point for the evolution of constructional compositionality in animal communication and human language. [ABSTRACT FROM AUTHOR]

The field of linguistics concerns itself with understanding the human capacity for language. Compositionality is a key notion in this research tradition. Compositionality refers to the notion that the meaning of a complex linguistic unit is a function of the meanings of its constituent parts. However, the question as to whether compositionality is a defining feature of human language is a matter of debate: usage-based and constructionist approaches emphasize the pervasive role of idiomaticity in language, and argue that strict compositionality is the exception rather than the rule. We review the major discussion points on compositionality from a usage-based point of view, taking both spoken and signed languages into account. In addition, we discuss theories that aim at accounting for the emergence of compositional language through processes of cultural transmission as well as the debate of whether animal communication systems exhibit compositionality. We argue for a view that emphasizes the analyzability of complex linguistic units, providing a template for accounting for the multimodal nature of human language. [ABSTRACT FROM AUTHOR]

One of the great unknowns in language evolution is the transition from unstructured sign combination to grammatical structure. This paper investigates the central — while hitherto overlooked — role of functor–argument metaphor. This type of metaphor pervades modern language, but is absent in animal communication. It arises from the semantic clash between the default meanings of terms. Functor–argument metaphor became logically possible in protolanguage once sufficient vocabulary and basic compositionality arose, allowing for novel combinations of terms. For example, the verb to hide, a functor, could be combined not only with a concrete, spatial entity like food as its argument, but also with an abstract, non-spatial one like anger. Through this clash, to hide is reinterpreted as a metaphorical action. Functor–argument metaphor requires the possibility of term combinability and the existence of compositionality. At the same time, it transcends compositionality, forcing a non-literal interpretation. We argue that functor–argument metaphor led the development of protolanguage into fully-fledged language in multiple ways. Not only did it expand expressiveness, but it drove the development of syntax including the conventionalization and fixation of word order, and the development of demonstratives. Thus, functor–argument metaphor fills in multiple gaps in the trajectory from a protolanguage, with only some terms and simple term combinations, to the elaborate grammatical structures of fully-fledged human languages. [ABSTRACT FROM AUTHOR]

The combination of meaning-bearing units (e.g., words) into higher-order structures (e.g., compound words and phrases) is integral to human language. Despite this central role of syntax in language, little is known about its evolutionary progression. Comparative data using animal communication systems offer potential insights, but only a handful of species have been identified to combine meaningful calls together into larger signals. We investigated a candidate for syntax-like structure in the highly social chestnut-crowned babbler (Pomatostomus ruficeps). Using a combination of behavioral observations, acoustic analyses, and playback experiments, we test whether the form and function of maternal contact calls is modified by combining the core "piping" elements of such calls with at least one other call element or call. Results from the acoustic analyses (236 analysed calls from 10 individuals) suggested that piping call elements can be flexibly initiated with either "peow" elements from middle-distance contact calls or adult "begging" calls to form "peow-pipe" and "beg-pipe" calls. Behavioral responses to playbacks (20 trials to 7 groups) of natural peow-pipe and beg-pipe calls were comparable to those of artificially generated versions of each call using peow elements and begging calls from other contexts. Furthermore, responses to playbacks (34 trials to 7 groups) of the three forms of maternal contact calls (piping alone, peow-pipe, beg-pipe) differed. Together these data suggest that meaning encoded in piping calls is modified by combining such calls with begging calls or peow elements used in other contexts and so provide rare empirical evidence for syntactic-like structuring in a nonhuman animal. [ABSTRACT FROM AUTHOR]

Research on urban noises affecting acoustic communication of animals is a growing area of study and conservation concern. However, the consequences of aircraft noise on anuran acoustic communication have been explored on a restricted basis to date. In this study, we investigated the impact of aircraft overflights on the individual and chorus performance of acoustic signalling in the Pedregal frog (Eleutherodactylus grandis), a microendemic and threatened species from Mexico City. During the summer of 2021, we recorded acoustic signals from male individuals and conducted acoustic monitoring to analyse how chorus social interactions change due to aircraft overflights. For this purpose, we evaluated acoustic properties of the call, including call duration, dominant frequency, call amplitude, and call repetition rate. Additionally, we measured the amplitude of environmental noises and signals by means of two types of complementary methodological approaches. Our results show changes in the individual performance of acoustic signals with longer call duration, lower dominant frequency, and higher call amplitude due to aircraft overflights, while individual call repetition rate did not vary. Furthermore, a decrease in the number of calls within the chorus was observed during aircraft overflight. Overall, these results show that aircraft noise causes plastic changes in the acoustic signals of the Pedregal frog and that social interactions between conspecifics decrease, thus adding a new disturbance to this species that already suffers from other anthropogenic noises, and habitat fragmentation. [ABSTRACT FROM AUTHOR]

"Translation beyond translation studies" is a book edited by Kobus Marais that explores the concept of translation in various fields of study. The book can be read in two ways: as a collection of curiosities showcasing the interdisciplinary nature of translation, or as evidence of a reorientation towards a semiotic center of gravity for translation. The book includes contributions from scholars in diverse disciplines such as mathematics, computer science, biology, law, literature, and more. It offers a polyvocal perspective on translation and challenges traditional notions of what translation is. While the book may be messy and complex, it provides a stimulating and open account of translation that will inspire and provoke readers. [Extracted from the article]

Many building blocks of human language can be found within the vocal communication systems of other species, most notably songbirds. One of the most prominent of these building blocks is syntax. While studies of syntax are abundant, a lack of consensus on the definition of syntax in non‐human animal communication studies has led to much debate. Consistent and deliberate use of terminology is needed to facilitate understanding across disciplines. In addition, new terminology may better describe syntactic structure found in vocal signals that are devoid of semantic associations, such as birdsong. Here, we propose two terms to describe the types of syntax commonly found in birdsong: sequential syntax and dialectical syntax. Sequential syntax can be defined as the rules that govern the patterns of sound without regard to semantic meaning. Dialectic syntax can be defined as sequential syntax that is distinct among different populations or groups with behavioral significance for those groups. Taken together, these two terms can describe the type of syntax seen in ornamental signals, such as birdsong.

Over the last two decades, an emerging body of research has demonstrated that non-human animals exhibit the ability to combine context-specific calls into larger sequences. These structures have frequently been compared with language’s syntax, whereby linguistic units are combined to form larger structures, and leveraged to argue that syntax might not be unique to language. Currently, however, the overwhelming majority of examples of call combinations are limited to simple sequences comprising just two calls which differ dramatically from the open-ended hierarchical structuring of the syntax found in language. We revisit this issue by taking a whole-repertoire approach to investigate combinatoriality in common marmosets (Callithrix jacchus). We use Markov chain models to quantify the vocal sequences produced by marmosets providing evidence for structures beyond the bigram, including three-call and even combinations of up to eight or nine calls. Our analyses of these longer vocal sequences are suggestive of potential further internal organization, including some amount of recombination, nestedness and non-adjacent dependencies. We argue that data-driven, whole-repertoire analyses are fundamental to uncovering the combinatorial complexity of non-human animals and will further facilitate meaningful comparisons with language’s combinatoriality.

Positive and negative experiences can alter animal brain dopamine levels.1 When first arriving at a rewarding food source or beginning to waggle dance and recruit nestmates to food, honeybees have increased brain dopamine levels, indicating a desire for food.2 We provide the first evidence that an inhibitory signal, the stop signal, which counters waggle dancing and is triggered by negative events at the food source, can decrease head dopamine levels and dancing, independent of the dancer having any negative experiences. The hedonic value of food can therefore be depressed simply by the receipt of an inhibitory signal. Increasing the brain dopamine levels reduced the aversive effects of an attack, increasing the time that bees spent subsequently feeding and waggle dancing and decreasing their stop signaling and time spent in the hive. Because honeybees regulate food recruitment and its inhibition at the colony level, these results highlight the complex integration of colony information with a basic and highly conserved neural mechanism in mammals and insects.2 VIDEO ABSTRACT.

The emergence of complex social interactions is predicted to be an important selective force in the diversification of communication systems. Parental care presents a key social context in which to study the evolution of novel signals, as care often requires communication and behavioral coordination between parents and is an evolutionary stepping-stone toward increasingly complex social systems. Anuran amphibians (frogs and toads) are a classic model of acoustic communication and the vocal repertoires of many species have been characterized in the contexts of advertisement, courtship, and aggression, yet quantitative descriptions of calls elicited in the context of parental care are lacking. The biparental poison frog, Ranitomeya imitator, exhibits a remarkable parenting behavior in which females, cued by the calls of their male partners, feed tadpoles unfertilized eggs. Here, we characterized and compared calls across three social contexts, for the first time including a parental care context. We found that egg-feeding calls share some properties with both advertisement and courtship calls but also had unique properties. Multivariate analysis revealed high classification success for advertisement and courtship calls but misclassified nearly half of egg feeding calls as either advertisement or courtship calls. Egg feeding and courtship calls both contained less identity information than advertisement calls, as expected for signals used in close-range communication where uncertainty about identity is low and additional signal modalities may be used. Taken together, egg-feeding calls likely borrowed and recombined elements of both ancestral call types to solicit a novel, context-dependent parenting response.

Honey bees use a complex form of spatial referential communication. Their "waggle dance" communicates the direction, distance, and quality of a resource to nestmates by encoding celestial cues, retinal optic flow, and relative food value into motion and sound within the nest. We show that correct waggle dancing requires social learning. Bees without the opportunity to follow any dances before they first danced produced significantly more disordered dances with larger waggle angle divergence errors and encoded distance incorrectly. The former deficit improved with experience, but distance encoding was set for life. The first dances of bees that could follow other dancers showed neither impairment. Social learning, therefore, shapes honey bee signaling, as it does communication in human infants, birds, and multiple other vertebrate species.

Abstract The aim of the current study was to investigate the influence of both intra- and interspecific audiences on dogs' facial expressions and behaviours. Forty-six dogs were exposed to three test conditions in which a food reward, initially available, was denied when in the presence of either a human (Human condition) or a dog audience (Dog condition), or in the absence of a visible audience (Non-social condition). Salivary cortisol was collected to evaluate the stress/arousal activation in the different conditions. Compared to the Non-social condition, the presence of a conspecific evoked more facial expressions, according to the DogFACS (Facial Action Coding System, an anatomically based tool to analyze facial expressions in domestic dogs), (EAD105—Ears downward), displacement behaviours (AD137—Nose licking, AD37—Lip wiping), tail wagging, whining, and panting (AD126). When facing a conspecific, dogs assumed a more avoidant attitude, keeping a distance and not looking at the stimuli, compared to when in the presence of the human partner. Dogs also exhibited more facial expressions (EAD102—Ears Adductor, EAD104—Ears Rotator), displacement behaviours (AD137—Nose licking, AD37—Lip wiping), panting (AD126) and whining when facing the conspecific than the human partner. Post-test cortisol was not influenced by any condition, and no association between pre-test cortisol and behavioural variables was found, thus strong differences in the levels of stress/arousal were unlikely to be responsible for differences in behavior between conditions. Considering the current results in the context of the available literature, we suggest that the higher displacement behaviors exhibited with the conspecifics were likely due to an increased level of uncertainty regarding the situations.

The categorization of animal vocalizations into distinct behaviorally relevant groups for communication is an essential operation that must be performed by the auditory system. This auditory object recognition is a difficult task that requires selectivity to the group identifying acoustic features and invariance to renditions within each group. We find that small ensembles of auditory neurons in the forebrain of a social songbird can code the bird's entire vocal repertoire (∼10 call types). Ensemble neural discrimination is not, however, correlated with single unit selectivity, but instead with how well the joint single unit tunings to characteristic spectro-temporal modulations span the acoustic subspace optimized for the discrimination of call types. Thus, akin to face recognition in the visual system, call type recognition in the auditory system is based on a sparse code representing a small number of high-level features and not on highly selective grandmother neurons.

Philosophy drawing on studies of animal behavior has paved a middle-way path regarding natural and non-natural meaning (Bar-On, 2021; Bar-On & Moore, 2017; Green, 2019; Moore, 2018). Elaborating the question of communicative intention goes hand-in-hand with growing appreciation of the reaches of non-human animal mindedness (Andrews & Beck, 2018; Merritt, 2021), pushing the plausible bounds of higher-order cognitive capacities beyond the singular province of homo sapiens. The question of relating human languaging to non-human languaging is enriched through a dialogue between enactive philosophy of social cognition and post-Gricean discourse. Speaker meaning presupposes coherent, stable, individual, internal, and prior intention as a cognitive or mental state. The enactive theory of social cognition, participatory sense-making (De Jaegher & Di Paolo, 2007), calls all of these premises into serious question. Prioritizing the role of interactions in cognition brings attention to the multitude of possible partners humans had and have in communication and sense-making engagements.

The goal of this paper is to analyze the notion of “compositionality” and its use in contemporary cognitive science. We argue that the concept has undergone a series of apparently minor definitional shifts since its initial inception within the field of philosophy of language (as indicated by Janssen, 2012). These changes result in a divergent meaning of the term as it is used in the emergent communication and language evolution communities. Hitherto, this fact has been underappreciated, whereas we believe that it has significant implications for understanding the nature of syntax and the sources of linguistic and conceptual structure. We argue that originally, “compositionality” was understood as pertaining primarily to the process of understanding a compound utterance by a hearer. Other scholars, however, take it to be a prerequisite of the structure of languages. In all contexts, investigating compositionality of natural languages requires making a host of idealizing assumptions. For this reason, we propose to understand compositionality as just one idealized principle influencing the construction of compound expressions in language, necessarily complemented by other principles. This allows for appreciating the structural entanglements permeating natural language and opens new avenues for accounting for them.

Vocalisations are widely used to signal behavioural intention in animal communication, but may also carry acoustic signatures unique to the calling individual. Here, we used acoustic analysis to confirm that Manx shearwater Puffinus puffinus calls carry individual signatures, and discerned which features made the calls individual. Manx shearwater are nocturnal seabirds that breed in dense colonies, where they must recognize and locate mates among thousands of conspecifics calling in the dark. There is evidence for mate vocal recognition in two shearwater species, but quantitative data on the vocalisations are lacking. We elicited vocal responses to playback of conspecific calls in Manx shearwaters, and measured spectral and temporal parameters of the calls. We then applied linear discriminant analysis with leave‐one‐out cross‐validation and could confirm the presence of individual vocal signatures. We then calculated among‐individual repeatability of 34 features describing the vocalisation to determine the extent to which these features may contribute to individual signature coding. We found that calls cluster by individual in both temporal and spectral characteristics, suggesting these traits are contributing to Manx shearwaters' unique call signatures. [ABSTRACT FROM AUTHOR]

Many animal species depend on sound to communicate with conspecifics. However, human‐generated (anthropogenic) noise may mask acoustic signals and so disrupt behavior. Animals may use various strategies to circumvent this, including shifts in the timing of vocal activity and changes to the acoustic parameters of their calls. We tested whether pied tamarins (Saguinus bicolor) adjust their vocal behavior in response to city noise. We predicted that both the probability of occurrence and the number of long calls would increase in response to anthropogenic noise and that pied tamarins would temporally shift their vocal activity to avoid noisier periods. At a finer scale, we anticipated that the temporal parameters of tamarin calls (e.g., call duration and syllable repetition rate) would increase with noise amplitude. We collected information on the acoustic environment and the emission of long calls in nine wild pied tamarin groups in Manaus, Brazil. We found that the probability of long‐call occurrence increased with higher levels of anthropogenic noise, though the number of long calls did not. The number of long calls was related to the time of day and the distance from home range borders—a proxy for the distance to neighboring groups. Neither long‐call occurrence nor call rate was related to noise levels at different times of day. We found that pied tamarins decreased their syllable repetition rate in response to anthropogenic noise. Long calls are important for group cohesion and intergroup communication. Thus, it is possible that the tamarins emit one long call with lower syllable repetition, which might facilitate signal reception. The occurrence and quantity of pied tamarin' long calls, as well as their acoustic proprieties, seem to be governed by anthropogenic noise, time of the day, and social mechanisms such as proximity to neighboring groups. Highlights: Anthropogenic noise may mask animal sounds and to circumvent this, animals may use various behavioral strategies.Pied tamarins increase call occurrence and reduce syllable repetition rate in response to anthropogenic noise.The number of calls emitted was not related to anthropogenic noise levels, but the time of day and the distance from the border of their home ranges, proxy for the distance to neighboring groups. [ABSTRACT FROM AUTHOR]

Identifying the evolutionary drivers of sexual signal complexity is a key challenge in the study of animal communication. Among mammals, male bovids and cervids often perform elaborate gestural displays during courtship, consisting of ritualized movements of various parts of the body but the causes underlying interspecific variation in complexity of such displays remain poorly understood. Here we apply the comparative method to investigate which factors may have either promoted or constrained gestural repertoire size. We found that sexual selection was a strong predictor of gestural display complexity in male bovids and cervids. Repertoire size was positively correlated with breeding group size, an indicator of the intensity of sexual selection in males. Moreover, repertoires were larger in species adopting nonterritorial and lek breeding mating systems than in species adopting resource-defence territoriality, a finding that can be explained by more emphasis on direct benefits than indirect benefits in resource-defence systems, where male mating success may also be less skewed due to difficulty in monopolizing mates. The results also indicate that gestural repertoire size was positively correlated with the number of closely related species occurring in sympatry. This is consistent with display complexity being selected to facilitate species recognition during courtship and thereby avoid interspecific hybridization. At the same time, repertoire size was negatively associated with male body mass, possibly due to the energetic and mechanical constraints imposed on movements in very large species. By contrast, we found no evidence that the habitat drives selection for complex gestural courtship displays. [ABSTRACT FROM AUTHOR]

Vocal complexity is central to many evolutionary hypotheses about animal communication. Yet, quantifying and comparing complexity remains a challenge, particularly when vocal types are highly graded. Male Bornean orangutans (Pongo pygmaeus wurmbii) produce complex and variable "long call" vocalizations comprising multiple sound types that vary within and among individuals. Previous studies described six distinct call (or pulse) types within these complex vocalizations, but none quantified their discreteness or the ability of human observers to reliably classify them. We studied the long calls of 13 individuals to: (1) evaluate and quantify the reliability of audio-visual classification by three well-trained observers, (2) distinguish among call types using supervised classification and unsupervised clustering, and (3) compare the performance of different feature sets. Using 46 acoustic features, we used machine learning (i.e., support vector machines, affinity propagation, and fuzzy c-means) to identify call types and assess their discreteness. We additionally used Uniform Manifold Approximation and Projection (UMAP) to visualize the separation of pulses using both extracted features and spectrogram representations. Supervised approaches showed low inter-observer reliability and poor classification accuracy, indicating that pulse types were not discrete. We propose an updated pulse classification approach that is highly reproducible across observers and exhibits strong classification accuracy using support vector machines. Although the low number of call types suggests long calls are fairly simple, the continuous gradation of sounds seems to greatly boost the complexity of this system. This work responds to calls for more quantitative research to define call types and quantify gradedness in animal vocal systems and highlights the need for a more comprehensive framework for studying vocal complexity vis-à-vis graded repertoires. [ABSTRACT FROM AUTHOR]

Vocal rhythm plays a fundamental role in sexual selection and species recognition in birds, but little is known of its genetic basis due to the confounding effect of vocal learning in model systems. Uncovering its genetic basis could facilitate identifying genes potentially important in speciation. Here we investigate the genomic underpinnings of rhythm in vocal non-learning Pogoniulus tinkerbirds using 135 individual whole genomes distributed across a southern African hybrid zone. We find rhythm speed is associated with two genes that are also known to affect human speech, Neurexin-1 and Coenzyme Q8A. Models leveraging ancestry reveal these candidate loci also impact rhythmic stability, a trait linked with motor performance which is an indicator of quality. Character displacement in rhythmic stability suggests possible reinforcement against hybridization, supported by evidence of asymmetric assortative mating in the species producing faster, more stable rhythms. Because rhythm is omnipresent in animal communication, candidate genes identified here may shape vocal rhythm across birds and other vertebrates. Little is known about the genetic basis of the rhythmic component of bird song, an important trait in sexual selection and species recognition. By studying a system with innate vocalizations, the Pogoniulus tinkerbirds, this study finds candidate genes that underlie differences in speed in vocal rhythm in this system. [ABSTRACT FROM AUTHOR]

Comparative studies of animal communication systems are particularly important for understanding the origins and evolution of core features of human language like syntax and dialects. Recent studies have begun to develop bats as models for investigating shared traits with human language, given the complex social vocalizations of the former. Our previous research revealed that bat social calls contained almost 20 syllable types and the occurrence of these syllable types in the call sequences followed certain permutation rules. However, the differences in these patterns between populations remain unclear. Here, we examined the syntactic patterns of social calls in greater horseshoe bats, Rhinolophus ferrumequinum , from three geographically distant populations in China. The aggressive calls and behaviours during agonistic interactions of 26 bats were analysed to examine the consistency and variation between two aggression levels and across three populations. Common types of syllables, transitions and sequence patterns were found in all three populations. However, there were significant differences in the occurrence frequencies of shared syllable types, transition types and sequence types. Further, more noisy and composite syllables occurred when aggression was high than when it was low. There were also more transitions between noisy syllables and more repetitions in calls in a high aggression than in a low aggression context. The universal syntactic patterns and differences in social vocalizations of bats across different populations are of interest for fields of animal communication and language evolution. • Shared acoustic elements and patterns existed in social calls across populations. • Occurrence frequencies of vocalization types were different between populations. • High aggression calls were more noisy and complex than low aggression calls. [ABSTRACT FROM AUTHOR]

In the past years the relatively new field of veterinary management faced incredible challenges. In order to maintain the fluent workflow and guide the veterinary practitioners through economic and health crises the profession itself demanded a new skill-set to be implemented focused on the so-called soft skills. The present study focused on a survey among owners, managers and employees at veterinary clinics and hospitals in order to establish the level at which they have implemented some non-technical skills in their work. We investigated the amount of time during the workhours which the respondents used for non-clinical tasks as communication with animal owners, suppliers, governmental officers, colleagues, financial management and time management. The conclusions drawn could be used for improvement of the curriculum for veterinary professionals, addressing their needs for acquiring and updating their non-clinical skills and competences in managing their businesses. [ABSTRACT FROM AUTHOR]

The intricate tapestry of animal communication has long fascinated humanity, with the sophisticated linguistics of cetaceans holding a special place of intrigue due to the cetaceans' significant brain size and apparent intelligence. This Essay explores the legal implications of the recent advancements in artificial intelligence (AI), specifically machine learning and neural networks, that have made significant strides in deciphering sperm whale (Physeter macrocephalus) communication. We view the ability of a being to communicate as one--but not the only--potential pathway to qualify for legal rights. As such, we investigate the possibility that the ability to communicate should trigger legal rights for beings capable of communicating, whether they be cetaceans or other creatures. As the Cetacean Translation Initiative (CETI) project, which is actively working to unlock sperm whale language, moves closer to enabling meaningful humancetacean dialogue, we stand on the precipice of a transformative understanding that may compel a radical reevaluation of animal legal rights and, perhaps, human legal rights as well. In fact, viewing eligibility for legal rights through a more objective lens, such as a communication criterion, may even improve our understanding of human legal rights, their origins, extent, application, and even entitlement itself. We begin with an overview of animal communication, emphasizing the complex acoustic patterns of sperm whale songs and clicks, which have been captured and analyzed through the collaborative efforts of marine biologists and computer scientists. This cross-disciplinary effort has yielded what the Dominica Sperm Whale Project has named "Flukebook"--a robust dataset that informs machine-learning models with acoustic signals, contextual behavioral data, genetic data, and geospatial information--that opens the door to the potential of an interspecies large language model (LLM) useful for communication among sperm whales and humans. Having established that the prospect of communicating with another species is becoming increasingly feasible, we then delve into the philosophical and ethical considerations that accompany such a breakthrough. Drawing upon the perspectives of thinkers such as Jeremy Bentham, Professor Peter Singer, and Professor Martha Nussbaum, we investigate the ethical foundations for considering the legal rights of cetaceans, or other nonhuman animals. This investigation is juxtaposed with historical whaling laws and modern legal frameworks, probing the adequacy of current laws, norms, practices, and attitudes regarding emerging interspecies communication. Finally, we propose a novel legal paradigm that contends with the implications of cetacean communication capabilities. As we inch toward potentially understanding requests, preferences, or even rules or laws of sperm whales, the ethical imperative to reexamine their legal standing becomes undeniable. This Essay examines practical legal issues such as jurisdiction, standing, representation, autonomy, and the feasibility of animal citizenship. In fact, it envisions innovative legal constructs such as a "Magna Carta Cetacea" and a "United Species" extension of the United Nations. In addition, we endeavor to articulate an objective standard by which any being capable of the requisite communication qualifies for legal rights. In this potential legal frontier, the communication of preferences by an animal may necessitate that we seriously consider conferring legal rights to those animals. This groundbreaking dialogue could not only elevate the rights of whales, but also provoke a broader discussion about the principles underlying human legal rights themselves, challenging our current anthropocentric legal systems to evolve. As we decode the "codas" of sperm whales, we are challenged to reenvision the legal and normative matrix of life on Earth and our place within it, guided by potential principles such as mutual respect and legal recognition that transcend species boundaries. [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]

Underwater noise pollution is a significant environmental issue that can have detrimental effects on marine ecosystems. One of the main sources of underwater noise pollution is ship traffic, which has been shown to negatively impact marine animals by masking communication signals and altering their behaviors. This study represents the first comprehensive analysis of underwater ship noise in the Red Sea, wherein noise maps of ships sailing through the main shipping lane in the Red Sea were simulated by integrating both anthropogenic and environmental variables. These maps offer valuable insights for policymakers, enabling them to make informed decisions and implement targeted mitigation efforts. [ABSTRACT FROM AUTHOR]

Motion is the basis of nearly all animal behavior. Evolution has led to some extraordinary specializations of propulsion mechanisms among invertebrates, including the mandibles of the dracula ant and the claw of the pistol shrimp. In contrast, vertebrate skeletal movement is considered to be limited by the speed of muscle, saturating around 250 Hz. Here, we describe the unique propulsion mechanism by which Danionella cerebrum, a miniature cyprinid fish of only 12 mm length, produces high amplitude sounds exceeding 140 dB (re. 1 µPa, at a distance of one body length). Using a combination of high-speed video, micro-computed tomography (micro-CT), RNA profiling, and finite difference simulations, we found that D. cerebrum employ a unique sound production mechanism that involves a drumming cartilage, a specialized rib, and a dedicated muscle adapted for low fatigue. This apparatus accelerates the drumming cartilage at over 2,000 g, shooting it at the swim bladder to generate a rapid, loud pulse. These pulses are chained together to make calls with either bilaterally alternating or unilateral muscle contractions. D. cerebrum use this remarkable mechanism for acoustic communication with conspecifics. [ABSTRACT FROM AUTHOR]

Animal vocal communication often relies on call sequences. The temporal patterns of such sequences can be adjusted to other callers, follow complex rhythmic structures or exhibit a metronome‐like pattern (i.e., isochronous). How regular are the temporal patterns in animal signals, and what influences their precision? If present, are rhythms already there early in ontogeny? Here, we describe an exploratory study of Cape fur seal (Arctocephalus pusillus pusillus) barks—a vocalisation type produced across many pinniped species in rhythmic, percussive bouts. This study is the first quantitative description of barking in Cape fur seal pups. We analysed the rhythmic structures of spontaneous barking bouts of pups and adult females from the breeding colony in Cape Cross, Namibia. Barks of adult females exhibited isochrony, that is they were produced at fairly regular points in time. Instead, intervals between pup barks were more variable, that is skipping a bark in the isochronous series occasionally. In both age classes, beat precision, that is how well the barks followed a perfect template, was worse when barking at higher rates. Differences could be explained by physiological factors, such as respiration or arousal. Whether, and how, isochrony develops in this species remains an open question. This study provides evidence towards a rhythmic production of barks in Cape fur seal pups and lays the groundwork for future studies to investigate the development of rhythm using multidimensional metrics. [ABSTRACT FROM AUTHOR]

The grey heron is an extensively studied and widely distributed colonial bird species in the Old World; however, relevant information on the role played by vocalisations during the life cycle of individuals is still lacking. This research aimed to deepen the available knowledge on the repertoire and vocal behaviour of adults during the breeding season, through a bioacoustic approach and choosing as study areas two heronries in different environmental contexts. Colonies were monitored 2 days a week each, for 9 weeks, from 8:00 am to 6:00 pm (360 hr of sampling). Results showed that adults use a wide range of call types, mainly related to courtship and the reproductive phase. Vocalisations are emitted especially by males and are a key element during mate attraction, nest building, in breeding events and in strengthening bonds within pairs. Most vocalisations are expressed in the first weeks of the breeding cycle, concurrently with the maximum number of courtship males, which exhibit most of the detected sound categories and emit calls with lower frequencies than females. Moreover, these vocalisations are expressed to a greater extent in the heronry characterized by an important forest component, where an almost entirely exclusive sound category was detected. In conclusion, the results suggest a possible correlation between vocal behaviour and female choice. The wide variety of sound signals and the high rate of calls produced by males during attraction and courtship displays, together with the acoustic characteristics of the signals, could provide honest estimates of the quality of emitters. [ABSTRACT FROM AUTHOR]

Sounds produced by human activities are often loud and may mask acoustic signals used by other species for communication. To circumvent this, some animals use various strategies, including shifting modality completely or complementing acoustic information by using additional modalities to communicate. Here we used pied tamarins (Saguinus bicolor) as models to explore whether shifts in communication modalities occur under increased anthropogenic noise or deploy them complementarily. We predicted that in circumstances where noise could impede acoustic communication the study animals would exhibit more scent-marking behaviour (i.e. olfactory communication) while reducing the emission of long calls (i.e. acoustic communication). We collected information on vocal and scent-marking behaviour in nine groups of wild pied tamarins in urban forests in Manaus, Amazonian Brazil. We found that scent marking occurrence increased with noise amplitude, though long call numbers did not change. Thus, our results do not suggest a complete shift between channels but complementation of information, where scent marking may compensate for the impacts of anthropogenic noise on the acoustic channel. This is an interesting result from a conservation perspective as pied tamarins may be capable of coping with city noise to communicate with conspecifics, a key tenet of species survival. Some species shift communication channels in response to anthropogenic noise. Pied tamarins do not reduce the number of long calls in response to anthropogenic noise, but the occurrence of scent markings increases with noise levels. Pied tamarins do not shift between channels, but scent marking may be used to complement information between channels. [ABSTRACT FROM AUTHOR]

Duets are one of the most fascinating displays in animal vocal communication, where two animals fine-tune the timing of their emissions to create a coordinated signal. Duetting behavior is widespread in the animal kingdom and is present in insects, birds, and mammals. Duets are essential to regulate activities within and between social units. Few studies assessed the functions of these vocal emissions experimentally, and for many species, there is still no consensus on what duets are used for. Here, we reviewed the literature on the function of duets in non-human primates, investigating a possible link between the social organization of the species and the function of its duetting behavior. In primates and birds, social conditions characterized by higher promiscuity might relate to the emergence of duetting behavior. We considered both quantitative and qualitative studies, which led us to hypothesize that the shift in the social organization from pair living to a mixed social organization might have led to the emergence of mate defense and mate guarding as critical functions of duetting behavior. Territory/resource ownership and defense functions are more critical in obligate pair-living species. Finally, we encourage future experimental research on this topic to allow the formulation of empirically testable predictions. [ABSTRACT FROM AUTHOR]

Behavioural flexibility might help animals cope with costs of genetic variants under selection, promoting genetic adaptation. However, it has proven challenging to experimentally link behavioural flexibility to the predicted compensation of population‐level fitness. We tested this prediction using the field cricket Teleogryllus oceanicus. In Hawaiian populations, a mutation silences males and protects against eavesdropping parasitoids. To examine how the loss of this critical acoustic communication signal impacts offspring production and mate location, we developed a high‐resolution, individual‐based tracking system for low‐light, naturalistic conditions. Offspring production did not differ significantly in replicate silent versus singing populations, and fitness compensation in silent conditions was associated with significantly increased locomotion in both sexes. Our results provide evidence that flexible behaviour can promote genetic adaptation via compensation in reproductive output and suggest that rapid evolution of animal communication systems may be less constrained than previously appreciated. [ABSTRACT FROM AUTHOR]

Context: Understanding how species select resources often requires assessing the environment at different spatial scales. Although the function of latrines in animal communication and social interactions has been studied in several carnivores, latrine site selection remains under-researched. Objectives: We aimed to describe the characteristics of latrines and determine the environmental factors, operating at different scales, that drive latrine site selection by two sympatric genet species (Genetta genetta and G. tigrina) in an Albany Thicket landscape (South Africa). Methods: We used a multi-scale modelling framework to investigate latrine site selection by comparing environmental characteristics at used latrines with that of two random points at four different scales. We then adapted a match-control design to derive the probability of latrine site selection. Results: At the fine scale, genets selected latrine sites located in steeper slopes and boasting a higher availability of favourable micro-structures (e.g., burrows, termite mounds, hollow branches). At the landscape scale, latrines were positively associated with riverine forest corridors where they occurred in clusters. Genets avoided open areas and high terrain ruggedness to place their latrines. The best scale-independent model revealed the higher importance of edge habitats like riverine corridors and, to a lesser extent, dirt roads. Conclusions: This study outlines the importance of including fine scale variables in multi-scale selection studies, as they may reveal features that are crucial for animal marking behaviour. Overall, our findings highlight the scales at which various factors influence latrine site selection the most. Based on our results, we suggest management practices that maintain animal communication by preserving riverine habitats across landscapes. [ABSTRACT FROM AUTHOR]

Biotremology, officially coined in 2016, has rapidly emerged as a distinct scientific discipline, focusing on the study of substrate‐borne mechanical waves in animal communication, particularly among insects. Initially seen as a niche within bioacoustics, biotremology is now recognized for its broad significance, rivalling chemical communication in its prevalence. This special issue highlights the multidisciplinary nature of biotremology, with research spanning insect behaviour, ecology and pest management. Studies showcase advances in understanding vibrational communication across diverse insect taxa, the development of new tools for reliable playback experiments and the growing potential of biotremology in applied pest control. This collection provides a snapshot of a dynamic field in rapid expansion, pushing the boundaries of both fundamental research and practical applications. [ABSTRACT FROM AUTHOR]

Abstract The study of animal sounds in biology and ecology relies heavily upon time–frequency (TF) visualisation, most commonly using the short‐time Fourier transform (STFT) spectrogram. This method, however, has inherent bias towards either temporal or spectral details that can lead to misinterpretation of complex animal sounds. An ideal TF visualisation should accurately convey the structure of the sound in terms of both frequency and time, however, the STFT often cannot meet this requirement. We evaluate the accuracy of four TF visualisation methods (superlet transform [SLT], continuous wavelet transform [CWT] and two STFTs) using a synthetic test signal. We then apply these methods to visualise sounds of the Chagos blue whale, Asian elephant, southern cassowary, eastern whipbird, mulloway fish and the American crocodile. We show that the SLT visualises the test signal with 18.48%–28.08% less error than the other methods. A comparison between our visualisations of animal sounds and their literature descriptions indicates that the STFT's bias may have caused misinterpretations in describing pygmy blue whale songs and elephant rumbles. We suggest that use of the SLT to visualise low‐frequency animal sounds may prevent such misinterpretations. Finally, we employ the SLT to develop ‘BASSA’, an open‐source, GUI software application that offers a no‐code, user‐friendly tool for analysing short‐duration recordings of low‐frequency animal sounds for the Windows platform. The SLT visualises low‐frequency animal sounds with improved accuracy, in a user‐friendly format, minimising the risk of misinterpretation while requiring less technical expertise than the STFT. Using this method could propel advances in acoustics‐driven studies of animal communication, vocal production methods, phonation and species identification.

Social deep-diving odontocetes face the challenge of balancing near-surface proximity to oxygen and group members with foraging in the deep sea. Individuals rely on conspecifics for critical life functions, such as predator defence, but disperse during foraging to feed individually. To understand the role of social acoustic mediation during foraging in deep-diving toothed whales, we investigated the context of social burst-pulse call production in Risso’s dolphin (Grampus griseus) using biologgers. Dolphins produced context-specific burst pulses predominantly during daytime foraging, preceding or following foraging dives and in the early descent of daytime deep dives. Individuals applied differential short and long burst-pulse calls intended for either near-surface receivers (horizontal transmission) or deep-foraging receivers (vertical transmission). Our results show that deep-diving toothed whales are reliant on acoustic communication during certain foraging contexts, to relay information including foraging conditions or an individual’s location. Moreover, they accentuate the importance of maintaining acoustic contact with conspecifics, specifically when dispersed during deeper foraging. It also signifies that our oceanic top predators may be specifically vulnerable to the current strong increase in anthropogenic noise. Potential masking of the signals from group members communicating at a distance could undermine their social cohesion, and hence their capacity to maintain vital life functions.