PeerJ Preprints: Animal Behaviorhttps://peerj.com/preprints/index.atom?journal=peerj&subject=120Animal Behavior articles published in PeerJ PreprintsDevelopment and application of a robotic zebra finch (RoboFinch) to study multimodal cues in vocal communicationhttps://peerj.com/preprints/28004v32019-12-302019-12-30Ralph SimonJudith VarkevisserEzequiel MendozaKlaus HochradelConstance ScharffKatharina RiebelWouter Halfwerk
Understanding animal behaviour through psychophysical experimentation is often limited by insufficiently realistic stimulus representation. Important physical dimensions of signals and cues, especially those that are outside the spectrum of human perception, can be difficult to standardize and control separately with currently available recording and displaying techniques (e.g. video displays). Accurate stimulus control is in particular important when studying multimodal signals, as spatial and temporal alignment between stimuli is often crucial. Especially for audiovisual presentations, some of these limitations can be circumvented by the employment of animal robots that are superior to video presentations in all situations requiring realistic 3D presentations to animals. Here we report the development of a robotic zebra finch, called RoboFinch, and how it can be used to study vocal learning in a songbird, the zebra finch.
Understanding animal behaviour through psychophysical experimentation is often limited by insufficiently realistic stimulus representation. Important physical dimensions of signals and cues, especially those that are outside the spectrum of human perception, can be difficult to standardize and control separately with currently available recording and displaying techniques (e.g. video displays). Accurate stimulus control is in particular important when studying multimodal signals, as spatial and temporal alignment between stimuli is often crucial. Especially for audiovisual presentations, some of these limitations can be circumvented by the employment of animal robots that are superior to video presentations in all situations requiring realistic 3D presentations to animals. Here we report the development of a robotic zebra finch, called RoboFinch, and how it can be used to study vocal learning in a songbird, the zebra finch.A study on the Lombard Effect in telepresence roboticshttps://peerj.com/preprints/280072019-10-142019-10-14Ambre DavatGang FengVéronique Aubergé
In this study, we present a new experiment in order to study the Lombard effect in telepresence robotics. In this experiment, one person talks with a robot controled remotely by someone in a different room. The remote pilot (R) is immersed in both environments, while the local interlocutor (L) interacts directly with the robot. In this context, the position of the noise source, in the remote or in the local room, may modify the subjects’ voice adaptations. In order to study in details this phenomenon, we propose four particular conditions: no added noise, noise in room R heard only by R, virtual noise in room L heard only by R, and noise in room L heard by both R and L. We measured the variations of maximum intensity in order to quantify the Lombard effect. Our results show that there is indeed a modification of voice intensity in all noisy conditions. However, the amplitude of this modification varies depending on the condition.
In this study, we present a new experiment in order to study the Lombard effect in telepresence robotics. In this experiment, one person talks with a robot controled remotely by someone in a different room. The remote pilot (R) is immersed in both environments, while the local interlocutor (L) interacts directly with the robot. In this context, the position of the noise source, in the remote or in the local room, may modify the subjects’ voice adaptations. In order to study in details this phenomenon, we propose four particular conditions: no added noise, noise in room R heard only by R, virtual noise in room L heard only by R, and noise in room L heard by both R and L. We measured the variations of maximum intensity in order to quantify the Lombard effect. Our results show that there is indeed a modification of voice intensity in all noisy conditions. However, the amplitude of this modification varies depending on the condition.Endless forms of sexual selectionhttps://peerj.com/preprints/275842019-10-012019-10-01Willow R LindsayStaffan AnderssonBadreddine BererhiJacob HöglundArild JohnsenCharlotta KvarnemoErica H LederJan T LifjeldCalum E NinnesMats OlssonGeoff A ParkerTommaso PizzariAnna QvarnströmRebecca J SafranOla SvenssonScott Edwards
In recent years, the field of sexual selection has exploded, with advances in theoretical and empirical research complementing each other in exciting ways. This perspective piece is the product of a “stock-taking” workshop on sexual selection and conflict. Our aim is to identify and deliberate on outstanding questions and to stimulate discussion rather than provide a comprehensive overview of the entire field. These questions are organized into four thematic sections we deem essential to the field. First we focus on the evolution of mate choice and mating systems. Variation in mate quality can generate both competition and choice in the opposite sex, with implications for the evolution of mating systems. Limitations on mate choice may dictate the importance of direct vs. indirect benefits in mating decisions and consequently, mating systems, especially with regard to polyandry. Second, we focus on how sender and receiver mechanisms shape signal design. Mediation of honest signal content likely depends on integration of temporally variable social and physiological costs that are challenging to measure. We view the neuroethology of sensory and cognitive receiver biases as the main key to signal form and the ‘aesthetic sense’ proposed by Darwin. Since a receiver bias is sufficient to both initiate and drive ornament or armament exaggeration, without a genetically correlated or even coevolving receiver, this may be the appropriate ‘null model’ of sexual selection. Thirdly, we focus on the genetic architecture of sexually selected traits. Despite advances in modern molecular techniques, the number and identity of genes underlying performance, display and secondary sexual traits remains largely unknown. In-depth investigations into the genetic basis of sexual dimorphism in the context of long-term field studies will reveal constraints and trajectories of sexually selected trait evolution. Finally, we focus on sexual selection and conflict as drivers of speciation. Population divergence and speciation are often influenced by an interplay between sexual and natural selection. The extent to which sexual selection promotes or counteracts population divergence may vary depending on the genetic architecture of traits as well as the covariance between mating competition and local adaptation. Additionally, post-copulatory processes, such as selection against heterospecific sperm, may influence the importance of sexual selection in speciation. We propose that efforts to resolve these four themes can catalyze conceptual progress in the field of sexual selection, and we offer potential avenues of research to advance this progress.
In recent years, the field of sexual selection has exploded, with advances in theoretical and empirical research complementing each other in exciting ways. This perspective piece is the product of a “stock-taking” workshop on sexual selection and conflict. Our aim is to identify and deliberate on outstanding questions and to stimulate discussion rather than provide a comprehensive overview of the entire field. These questions are organized into four thematic sections we deem essential to the field. First we focus on the evolution of mate choice and mating systems. Variation in mate quality can generate both competition and choice in the opposite sex, with implications for the evolution of mating systems. Limitations on mate choice may dictate the importance of direct vs. indirect benefits in mating decisions and consequently, mating systems, especially with regard to polyandry. Second, we focus on how sender and receiver mechanisms shape signal design. Mediation of honest signal content likely depends on integration of temporally variable social and physiological costs that are challenging to measure. We view the neuroethology of sensory and cognitive receiver biases as the main key to signal form and the ‘aesthetic sense’ proposed by Darwin. Since a receiver bias is sufficient to both initiate and drive ornament or armament exaggeration, without a genetically correlated or even coevolving receiver, this may be the appropriate ‘null model’ of sexual selection. Thirdly, we focus on the genetic architecture of sexually selected traits. Despite advances in modern molecular techniques, the number and identity of genes underlying performance, display and secondary sexual traits remains largely unknown. In-depth investigations into the genetic basis of sexual dimorphism in the context of long-term field studies will reveal constraints and trajectories of sexually selected trait evolution. Finally, we focus on sexual selection and conflict as drivers of speciation. Population divergence and speciation are often influenced by an interplay between sexual and natural selection. The extent to which sexual selection promotes or counteracts population divergence may vary depending on the genetic architecture of traits as well as the covariance between mating competition and local adaptation. Additionally, post-copulatory processes, such as selection against heterospecific sperm, may influence the importance of sexual selection in speciation. We propose that efforts to resolve these four themes can catalyze conceptual progress in the field of sexual selection, and we offer potential avenues of research to advance this progress.Vocal interactivity in crowds, flocks and swarms: implications for voice user interfaceshttps://peerj.com/preprints/279812019-09-242019-09-24Roger K Moore
Recent years have seen an explosion in the availability of Voice User Interfaces. However, user surveys suggest that there are issues with respect to usability, and it has been hypothesised that contemporary voice-enabled systems are missing crucial behaviours relating to user engagement and vocal interactivity. However, it is well established that such ostensive behaviours are ubiquitous in the animal kingdom, and that vocalisation provides a means through which interaction may be coordinated and managed between individuals and within groups. Hence, this paper reports results from a study aimed at identifying generic mechanisms that might underpin coordinated collective vocal behaviour with a particular focus on closed-loop negative-feedback control as a powerful regulatory process. A computer-based real-time simulation of vocal interactivity is described which has provided a number of insights, including the enumeration of a number of key control variables that may be worthy of further investigation.
Recent years have seen an explosion in the availability of Voice User Interfaces. However, user surveys suggest that there are issues with respect to usability, and it has been hypothesised that contemporary voice-enabled systems are missing crucial behaviours relating to user engagement and vocal interactivity. However, it is well established that such ostensive behaviours are ubiquitous in the animal kingdom, and that vocalisation provides a means through which interaction may be coordinated and managed between individuals and within groups. Hence, this paper reports results from a study aimed at identifying generic mechanisms that might underpin coordinated collective vocal behaviour with a particular focus on closed-loop negative-feedback control as a powerful regulatory process. A computer-based real-time simulation of vocal interactivity is described which has provided a number of insights, including the enumeration of a number of key control variables that may be worthy of further investigation.Large-scale unsupervised clustering of Orca vocalizations: a model for describing orca communication systemshttps://peerj.com/preprints/279792019-09-242019-09-24Marion PoupardPaul BestJan SchlüterHelena SymondsPaul SpongHervé Glotin
Killer whales (Orcinus orca) can produce 3 types of signals: clicks, whistles and vocalizations. This study focuses on Orca vocalizations from northern Vancouver Island (Hanson Island) where the NGO Orcalab developed a multi-hydrophone recording station to study Orcas. The acoustic station is composed of 5 hydrophones and extends over 50 km 2 of ocean. Since 2015 we are continuously streaming the hydrophone signals to our laboratory in Toulon, France, yielding nearly 50 TB of synchronous multichannel recordings. In previous work, we trained a Convolutional Neural Network (CNN) to detect Orca vocalizations, using transfer learning from a bird activity dataset. Here, for each detected vocalization, we estimate the pitch contour (fundamental frequency). Finally, we cluster vocalizations by features describing the pitch contour. While preliminary, our results demonstrate a possible route towards automatic Orca call type classification. Furthermore, they can be linked to the presence of particular Orca pods in the area according to the classification of their call types. A large-scale call type classification would allow new insights on phonotactics and ethoacoustics of endangered Orca populations in the face of increasing anthropic pressure.
Killer whales (Orcinus orca) can produce 3 types of signals: clicks, whistles and vocalizations. This study focuses on Orca vocalizations from northern Vancouver Island (Hanson Island) where the NGO Orcalab developed a multi-hydrophone recording station to study Orcas. The acoustic station is composed of 5 hydrophones and extends over 50 km 2 of ocean. Since 2015 we are continuously streaming the hydrophone signals to our laboratory in Toulon, France, yielding nearly 50 TB of synchronous multichannel recordings. In previous work, we trained a Convolutional Neural Network (CNN) to detect Orca vocalizations, using transfer learning from a bird activity dataset. Here, for each detected vocalization, we estimate the pitch contour (fundamental frequency). Finally, we cluster vocalizations by features describing the pitch contour. While preliminary, our results demonstrate a possible route towards automatic Orca call type classification. Furthermore, they can be linked to the presence of particular Orca pods in the area according to the classification of their call types. A large-scale call type classification would allow new insights on phonotactics and ethoacoustics of endangered Orca populations in the face of increasing anthropic pressure.A small shift in VSH-gene frequency instead of rapid parallel evolution in bees. A comment on Oddie et al. 2018https://peerj.com/preprints/279382019-09-242019-09-24Jacques J M van AlphenBartJan Fernhout
We refute a recent claim that parallel evolution in four European populations of honeybees has resulted in a not previously reported behavioural defence mechanism of the bees against the parasitic mite Varroa destructor, i.e. the ability of uncapping/recapping to reduce mite reproductive success. There are no data to support this claim, while there is a more plausible alternative interpretation of the reduced mite reproduction, i.e. reduction of mites through Varroa Sensitive Hygiene. We provide evidence why the former mechanism cannot explain resistance against Varroa in honeybees and the latter is instrumental in reducing Varroa populations.
We refute a recent claim that parallel evolution in four European populations of honeybees has resulted in a not previously reported behavioural defence mechanism of the bees against the parasitic mite Varroa destructor, i.e. the ability of uncapping/recapping to reduce mite reproductive success. There are no data to support this claim, while there is a more plausible alternative interpretation of the reduced mite reproduction, i.e. reduction of mites through Varroa Sensitive Hygiene. We provide evidence why the former mechanism cannot explain resistance against Varroa in honeybees and the latter is instrumental in reducing Varroa populations.Not all grooming is equal: differential effects of political vs affiliative grooming on cytokines and glucocorticoids in rhesus macaqueshttps://peerj.com/preprints/279612019-09-152019-09-15Lauren J WooddellJessica J VandeleestAmy C NathmanBrianne A BeisnerBrenda McCowan
Positive social relationships in humans are known to have health promoting effects while negative social relationships have detrimental effects. Features of the broader social network, including indirect connections, also impact health. However, complicating our ability to examine these features, human networks are diverse and difficult to fully quantify. Animal models where social networks can be fully characterized are useful in examining how structurally similar yet functionally different relationships can differentially relate to biomarkers of health. For example, in nonhuman primates, grooming serves two main functions, to maintain social bonds (family/friends networks) or gain access to resources/support (political networks). We examined whether an individual’s position in these two network types was differentially related to biomarkers of inflammation and physiological stress in female rhesus macaques (Macaca mulatta). Consistent with predictions, females with higher family/friends centrality had lower IL-6/TNF-α levels, while females with high political centrality showed elevated levels. Middle-ranking females with high political centrality showed elevated hair cortisol yet little to no benefit of family/friend centrality. These results indicate that while grooming interactions are structurally similar, they may be functionally distinct and therefore have very different, even opposite, effects on health. Affiliative interactions occurring within the context of an established relationship (i.e., family/friends) can provide opportunities for social buffering. In contrast, interactions among individuals without established relationships, even friendly interactions, may ultimately be physiologically costly. Ultimately, these results indicate that while social relationships may appear similar, the underlying functionality can have fundamentally diverse physiological outcomes.
Positive social relationships in humans are known to have health promoting effects while negative social relationships have detrimental effects. Features of the broader social network, including indirect connections, also impact health. However, complicating our ability to examine these features, human networks are diverse and difficult to fully quantify. Animal models where social networks can be fully characterized are useful in examining how structurally similar yet functionally different relationships can differentially relate to biomarkers of health. For example, in nonhuman primates, grooming serves two main functions, to maintain social bonds (family/friends networks) or gain access to resources/support (political networks). We examined whether an individual’s position in these two network types was differentially related to biomarkers of inflammation and physiological stress in female rhesus macaques (Macaca mulatta). Consistent with predictions, females with higher family/friends centrality had lower IL-6/TNF-α levels, while females with high political centrality showed elevated levels. Middle-ranking females with high political centrality showed elevated hair cortisol yet little to no benefit of family/friend centrality. These results indicate that while grooming interactions are structurally similar, they may be functionally distinct and therefore have very different, even opposite, effects on health. Affiliative interactions occurring within the context of an established relationship (i.e., family/friends) can provide opportunities for social buffering. In contrast, interactions among individuals without established relationships, even friendly interactions, may ultimately be physiologically costly. Ultimately, these results indicate that while social relationships may appear similar, the underlying functionality can have fundamentally diverse physiological outcomes.Call overlapping signals sexual status in Darwin’s frogshttps://peerj.com/preprints/279432019-09-072019-09-07Jose M SerranoNoé GuzmánMario PennaMarco A MéndezClaudio Soto-Azat
Background. In animal reproductive contexts, calling behaviour is mostly performed by males but in species in which females call, it is not known how vocal interaction occurs between sexes, particularly when sexual dimorphism in signals is low, as in cases in which call repertoire is identical but acoustic properties differ. In Darwin’s frog (Rhinoderma darwinii), a species in which males brood larvae inside their vocal sacs, females have higher dominant frequency and shorter calls and notes than males. Since in this species males persist calling after getting pregnant with larvae, different vocal interaction patterns are expected to occur among animals having dissimilar reproductive status.
Methodology. To explore the mechanisms underlying vocal recognition among the different sexual status of R. darwinii, we recorded natural duets between non-pregnant males (NPM), pregnant males (PM) and females (F) and evaluated their evoked vocal response to natural playback stimuli of each sexual status from November to February 2015-2016 in Chiloé island, Chile. Call rate, phase angles, sound pressure level (SPL), number of overlapping calls and delay of overlapping calls were measured to determine differential responses between natural duets and in response to stimuli consisting of natural calls of individuals of different sexual status.
Results. Spontaneous duet interactions occurred mainly between males and no clear differences between duets were detected. In playbacks, call ratios in response to calls of different sexual status were similar. Females decreased their SPL in response to F calls, while F and PM had longer call delays and lower call overlaps between each other. Major differences were observed in call overlap, as the occurrence of this phenomenon was larger in playback experiments than during natural duets. The number of calls overlapped during natural duets was fewer (10.9 %) than during playback experiments (36.8 %).
Conclusions. Our results suggest that in R. darwinii, PM and F signalize their sexual status by decreasing their call overlap and that NPM respond indistinctly to the other sexual status. In general, these differences in selective call overlap between Darwin's frogs arise as a novel mechanism for signal recognition between animal vocal interactions.
Background. In animal reproductive contexts, calling behaviour is mostly performed by males but in species in which females call, it is not known how vocal interaction occurs between sexes, particularly when sexual dimorphism in signals is low, as in cases in which call repertoire is identical but acoustic properties differ. In Darwin’s frog (Rhinoderma darwinii), a species in which males brood larvae inside their vocal sacs, females have higher dominant frequency and shorter calls and notes than males. Since in this species males persist calling after getting pregnant with larvae, different vocal interaction patterns are expected to occur among animals having dissimilar reproductive status.Methodology. To explore the mechanisms underlying vocal recognition among the different sexual status of R. darwinii, we recorded natural duets between non-pregnant males (NPM), pregnant males (PM) and females (F) and evaluated their evoked vocal response to natural playback stimuli of each sexual status from November to February 2015-2016 in Chiloé island, Chile. Call rate, phase angles, sound pressure level (SPL), number of overlapping calls and delay of overlapping calls were measured to determine differential responses between natural duets and in response to stimuli consisting of natural calls of individuals of different sexual status.Results. Spontaneous duet interactions occurred mainly between males and no clear differences between duets were detected. In playbacks, call ratios in response to calls of different sexual status were similar. Females decreased their SPL in response to F calls, while F and PM had longer call delays and lower call overlaps between each other. Major differences were observed in call overlap, as the occurrence of this phenomenon was larger in playback experiments than during natural duets. The number of calls overlapped during natural duets was fewer (10.9 %) than during playback experiments (36.8 %).Conclusions. Our results suggest that in R. darwinii, PM and F signalize their sexual status by decreasing their call overlap and that NPM respond indistinctly to the other sexual status. In general, these differences in selective call overlap between Darwin's frogs arise as a novel mechanism for signal recognition between animal vocal interactions.Vocal expression of emotional valence in pigs across multiple call types and contextshttps://peerj.com/preprints/279342019-09-032019-09-03Elodie BrieferPavel LinhartRichard PolichtMarek ŠpinkaLisette M C LeliveldSandra DüpjanBirger PuppeMónica Padilla de la TorreAndrew M JanczakCécile BourguetVéronique DeissAlain BoissyCarole GuérinEva ReadMarjorie CoulonEdna HillmannCéline Tallet
Emotions, unlike mood, are short-lived reactions associated with specific events. They can be characterized by two main dimensions, their arousal (bodily activation) and valence (negative versus positive). Knowledge of the valence of emotions experienced by domestic and captive animals is crucial for assessing and improving their welfare, as it enables us to minimize the negative emotions that they might experience and to promote positive ones. Emotions can affect vocalizations directly or indirectly through the brain, lungs, larynx or vocal tract. As a result, vocal expression of emotions has been observed across species, and could serve as a non-invasive and potentially very reliable tool to assess animal emotions. In pigs (Sus scrofa), vocal expression of emotions has been relatively well studied. However, it is not known if the vocal indicators revealed in previous studies are valid across call types and contexts. To find this out, we conducted a meta-analysis of the effects of emotional valence on pig vocalizations, including calls recorded in the most common emotional situations encountered by pigs throughout their lives, from birth to slaughter. Our analyses revealed that pigs produced calls characterized by a higher center of gravity, a shorter duration, less noise (lower Wiener entropy), lower formants (measured using the formant dispersion) and LPC coefficients in positive compared to negative contexts. Overall, these vocal parameters could be very useful for developing automated methods to monitor pig welfare on-farm.
Emotions, unlike mood, are short-lived reactions associated with specific events. They can be characterized by two main dimensions, their arousal (bodily activation) and valence (negative versus positive). Knowledge of the valence of emotions experienced by domestic and captive animals is crucial for assessing and improving their welfare, as it enables us to minimize the negative emotions that they might experience and to promote positive ones. Emotions can affect vocalizations directly or indirectly through the brain, lungs, larynx or vocal tract. As a result, vocal expression of emotions has been observed across species, and could serve as a non-invasive and potentially very reliable tool to assess animal emotions. In pigs (Sus scrofa), vocal expression of emotions has been relatively well studied. However, it is not known if the vocal indicators revealed in previous studies are valid across call types and contexts. To find this out, we conducted a meta-analysis of the effects of emotional valence on pig vocalizations, including calls recorded in the most common emotional situations encountered by pigs throughout their lives, from birth to slaughter. Our analyses revealed that pigs produced calls characterized by a higher center of gravity, a shorter duration, less noise (lower Wiener entropy), lower formants (measured using the formant dispersion) and LPC coefficients in positive compared to negative contexts. Overall, these vocal parameters could be very useful for developing automated methods to monitor pig welfare on-farm.Initial observation of human-bird vocal interactions in a zoological settinghttps://peerj.com/preprints/279272019-08-292019-08-29Rébecca KleinbergerJanet BakerGabriel Miller
Vocal interactions between humans and non-human animals are pervasive, but studies are often limited to communication within species. Here, we conducted a pilot exploration of vocal interactions between visitors to the San Diego Zoo Safari Park and Sampson, an 18-year-old male Hyacinth Macaw residing near the entrance. Over the course of one hour, 82 vocal and behavioral events were recorded, and various relationships between human and bird behavior were noted. Analyses of this type, applied to large datasets with assistance from artificial intelligence, could be used to better understand the impacts, positive or negative, of human visitors on animals in managed care.
Vocal interactions between humans and non-human animals are pervasive, but studies are often limited to communication within species. Here, we conducted a pilot exploration of vocal interactions between visitors to the San Diego Zoo Safari Park and Sampson, an 18-year-old male Hyacinth Macaw residing near the entrance. Over the course of one hour, 82 vocal and behavioral events were recorded, and various relationships between human and bird behavior were noted. Analyses of this type, applied to large datasets with assistance from artificial intelligence, could be used to better understand the impacts, positive or negative, of human visitors on animals in managed care.