Animal Studies Commons^™

Automated Bioacoustics: Methods In Ecology And Conservation And Their Potential For Animal Welfare Monitoring, Michael P. Mcloughlin, Rebecca Stewart, Alan G. Mcelligott

Alan G. McElligott, PhD

Vocalizations carry emotional, physiological and individual information. This suggests that they may serve as potentially useful indicators for inferring animal welfare. At the same time, automated methods for analysing and classifying sound have developed rapidly, particularly in the fields of ecology, conservation and sound scene classification. These methods are already used to automatically classify animal vocalizations, for example, in identifying animal species and estimating numbers of individuals. Despite this potential, they have not yet found widespread application in animal welfare monitoring. In this review, we first discuss current trends in sound analysis for ecology, conservation and sound classification. Following this, …

Perceptual Lateralization Of Vocal Stimuli In Goats, Luigi Baciadonna, Christian Nawroth, Elodie F. Briefer, Alan G. Mcelligott

Alan G. McElligott, PhD

Functional asymmetries, for example, the preferential involvement of 1 brain hemisphere to process stimuli, may increase brain efficiency and the capacity to carry out tasks simultaneously. We investigated which hemisphere was primarily involved in processing acoustic stimuli in goats using a head-orienting paradigm. Three playbacks using goat vocalizations recorded in different contexts: food anticipation (positive), isolation (negative), food frustration (negative), as well as 1 playback involving dog barks (negative) were presented on the left and right sides of the test subjects simultaneously. The head-orienting response (left or right) and latency to resume feeding were recorded. The direction of the head-orienting …

Goats Prefer Positive Human Emotional Facial Expressions, Christian Nawroth, Natalia Albuquerque, Carine Savalli, Marie-Sophie Single, Alan G. Mcelligott

Alan G. McElligott, PhD

Domestication has shaped the physiology and the behaviour of animals to better adapt to human environments. Therefore, human facial expressions may be highly informative for animals domesticated for working closely with people, such as dogs and horses. However, it is not known whether other animals, and particularly those domesticated primarily for production, such as goats, are capable of perceiving human emotional cues. In this study, we investigated whether goats can distinguish human facial expressions when simultaneously shown two images of an unfamiliar human with different emotional valences (positive/ happy or negative/angry). Both images were vertically attached to a wall on …

Individual Personality Differences In Goats Predict Their Performance In Visual Learning And Non-Associative Cognitive Tasks, Christian Nawroth, Pamela M. Prentice, Alan G. Mcelligott

Alan G. McElligott, PhD

Variation in common personality traits, such as boldness or exploration, is often associated with risk–reward trade–offs and behavioural flexibility. To date, only a few studies have examined the effects of consistent behavioural traits on both learning and cognition. We investigated whether certain personality traits (‘exploration’ and ‘sociability’) of individuals were related to cognitive performance, learning flexibility and learning style in a social ungulate species, the goat (Capra hircus). We also investigated whether a preference for feature cues rather than impaired learning abilities can explain performance variation in a visual discrimination task. We found that personality scores were consistent …

Individual Personality Differences In Goats Predict Their Performance In Visual Learning And Non-Associative Cognitive Tasks, Christian Nawroth, Pamela M. Prentice, Alan G. Mcelligott

Alan G. McElligott, PhD

Variation in common personality traits, such as boldness or exploration, is often associated with risk–reward trade–offs and behavioural flexibility. To date, only a few studies have examined the effects of consistent behavioural traits on both learning and cognition. We investigated whether certain personality traits (‘exploration’ and ‘sociability’) of individuals were related to cognitive performance, learning flexibility and learning style in a social ungulate species, the goat (Capra hircus). We also investigated whether a preference for feature cues rather than impaired learning abilities can explain performance variation in a visual discrimination task. We found that personality scores were consistent …

Vocal Individuality And Species Divergence In The Contact Calls Of Banded Penguins, Livio Favaro, Claudia Gili, Cristiano Da Rugna, Guido Gnone, Chiara Fissore, Daniel Sanchez, Alan G. Mcelligott, Marco Gamba, Daniela Pessani

Alan G. McElligott, PhD

Penguins produce contact calls to maintain social relationships and group cohesion. Such vocalisations have recently been demonstrated to encode individual identity information in the African penguin. Using a source-filter theory approach, we investigated whether acoustic cues of individuality can also be found in other Spheniscus penguins and the acoustic features of contact calls have diverged within this genus. We recorded vocalisations from two ex-situ colonies of Humboldt penguin and Magellanic penguin (sympatric and potentially interbreeding in the wild) and one ex-situ group of African penguins (allopatric although capable of interbreeding with the other two species in captivity). We measured 14 …

The Use Of Judgement Bias To Assess Welfare In Farm Livestock, L. Baciadonna, A. G. Mcelligott

Alan G. McElligott, PhD

The development of accurate measures of animal emotions is important for improving and promoting animal welfare. Cognitive bias indicates the effect of emotional states on cognitive processes, such as memory, attention, and judgement. Cognitive bias tests complement existing behavioural and physiological measures for assessing the valence of animal emotions indirectly. The judgement bias test has been used to assess emotional states in non-human animals; mainly in laboratory settings. The aim of this review is to summarise the findings on the use of the judgement bias test approach in assessing emotions in non-human animals, focusing in particular on farm livestock. The …

Social Effects On Vocal Ontogeny In An Ungulate, The Goat, Capra Hircus, Elodie F. Briefer, Alan G. Mcelligott

Alan G. McElligott, PhD

Vocal plasticity is the ability of an individual to modify its vocalizations according to its environment. Humans benefit from an extreme form of vocal plasticity, allowing us to produce a wide range of sounds. This capacity to modify sounds has been shown in three bird orders and in a few nonhuman mammal species, all characterized by complex vocal communication systems. In other mammals, there is no evidence for a social impact on vocal development. We investigated whether contact calls were affected by social environment and kinship during early ontogeny in goats, a highly vocal and social species. To test the …

Rescued Goats At A Sanctuary Display Positive Mood After Former Neglect, Elodie F. Briefer, Alan G. Mcelligott

Alan G. McElligott, PhD

Moods influence cognitive processes in that people in positive moods expect more positive events to occur and less negative ones (“optimistic bias”), whereas the opposite happens for people in negative moods (“pessimistic bias”). The evidence for an effect of mood on cognitive bias is also increasing in animals, suggesting that measures of optimism and pessimism could provide useful indicators of animal welfare. For obvious ethical reasons, serious poor treatments cannot be easily replicated in large mammals in order to study their long-term effects on moods. In this study, we tested the long-term effects (>2 years) of prior poor welfare …

Mutual Mother–Offspring Vocal Recognition In An Ungulate Hider Species (Capra Hircus), Elodie F. Briefer, Alan G. Mcelligott

Alan G. McElligott, PhD

Parent–offspring recognition can be essential for offspring survival and important to avoid misdirected parental care when progeny mingle in large social groups. In ungulates, offspring anti-predator strategies (hiding vs. following) result in differences in mother–offspring interactions, and thus different selection pressures acting on the recognition process during the first weeks of life. Hider offspring are isolated and relatively stationary and silent to avoid detection by predators, whereas follower offspring are mobile and rapidly mix in large social groups. For these reasons, hiders have been suggested to show low offspring call individuality leading to unidirectional recognition of mothers by offspring and …

Judgement Bias In Goats (Capra Hircus): Investigating The Effects Of Human Grooming, Luigi Baciadonna, Christian Nawroth, Alan G. Mcelligott

Alan G. McElligott, PhD

Animal emotional states can be investigated by evaluating their impact on cognitive processes. In this study, we used a judgement bias paradigm to determine if shortterm positive human-animal interaction (grooming) induced a positive affective state in goats. We tested two groups of goats and trained them to discriminate between a rewarded and a non-rewarded location over nine training days. During training, the experimental group (nD9) was gently groomed by brushing their heads and backs for five min over 11 days (nine training days, plus two testing days, total time 55 min). During training, the control group (nD10) did not experience …

Mother Goats Do Not Forget Their Kids’ Calls, Elodie F. Briefer, Mónica Padilla De La Torre, Alan G. Mcelligott

Alan G. McElligott, PhD

Parent–offspring recognition is crucial for offspring survival. At long distances, this recognition is mainly based on vocalizations. Because of maturation-related changes to the structure of vocalizations, parents have to learn successive call versions produced by their offspring throughout ontogeny in order to maintain recognition. However, because of the difficulties involved in following the same individuals over years, it is not clear how long this vocal memory persists. Here, we investigated long-term vocal recognition in goats. We tested responses of mothers to their kids’ calls 7–13 months after weaning. We then compared mothers’ responses to calls of their previous kids with …

Intrasexual Selection Drives Sensitivity To Pitch, Formants And Duration In The Competitive Calls Of Fallow Bucks, Benjamin J. Pitcher, Elodie Briefer, Alan G. Mcelligott

Alan G. McElligott, PhD

Background: Mammal vocal parameters such as fundamental frequency (or pitch; fo) and formant dispersion often provide information about quality traits of the producer (e.g. dominance and body size), suggesting that they are sexually selected. However, little experimental evidence exists demonstrating the importance of these cues in intrasexual competition, particularly fo. Male Fallow deer (bucks) produce an extremely low pitched groan. Bucks have a descended larynx and generate fo well below what is expected for animals of their size. Groan parameters are linked to caller dominance, body size and condition, suggesting that groans are the product of sexual selection. Using a …

Indicators Of Age, Body Size And Sex In Goat Kid Calls Revealed Using The Source–Filter Theory, Elodie F. Briefer, Alan G. Mcelligott

Alan G. McElligott, PhD

The source–filter theory is an important framework recently applied to the study of animal vocalisations, which links the mode of vocal production to call parameters. Vocalisations can be good indicators of a sender’s characteristics, such as identity, body size, age, and even hormonal status and affective states. For these reasons, applied vocal communication research would greatly benefit from adopting the source–filter theory approach to identify key call parameters linked to physical and physiological characteristics of domestic animals. Here, we introduce the source–filter theory through a detailed analysis and interpretation of goat contact calls during development. In mammals, vocal development is …

Human Head Orientation And Eye Visibility As Indicators Of Attention For Goats (Capra Hircus), Christian Nawroth, Alan G. Mcelligott

Alan G. McElligott, PhD

Animals domesticated for working closely with humans (e.g. dogs) have been shown to be remarkable in adjusting their behaviour to human attentional stance. However, there is little evidence for this form of information perception in species domesticated for production rather than companionship. We tested domestic ungulates (goats) for their ability to differentiate attentional states of humans. In the first experiment, we investigated the effect of body and head orientation of one human experimenter on approach behaviour by goats. Test subjects (N = 24) significantly changed their behaviour when the experimenter turned its back to the subjects, but did not take …

Goats Excel At Learning And Remembering A Highly Novel Cognitive Task, Elodie F. Briefer, Samaah Haque, Luigi Baciadonna, Alan G. Mcelligott

Alan G. McElligott, PhD

Introduction: The computational demands of sociality (maintaining group cohesion, reducing conflict) and ecological problems (extractive foraging, memorizing resource locations) are the main drivers proposed to explain the evolution cognition. Different predictions follow, about whether animals would preferentially learn new tasks socially or not, but the prevalent view today is that intelligent species should excel at social learning. However, the predictions were originally used to explain primate cognition, and studies of species with relatively smaller brains are rare. By contrast, domestication has often led to a decrease in brain size, which could affect cognition. In domestic animals, the relaxed selection pressures …

Mother--Offspring Recognition Via Contact Calls In Cattle, Bos Taurus, Mónica Padilla De La Torre, Elodie F. Briefer, Brad M. Ochocki, Alan G. Mcelligott, Tom Reader

Alan G. McElligott, PhD

Individual recognition in gregarious species is fundamental in order to avoid misdirected parental investment. In ungulates, two very different parental care strategies have been identified: ‘hider’ offspring usually lie concealed in vegetation whereas offspring of ‘follower’ species remain with their mothers while they forage. These two strategies have been suggested to impact on mother--offspring vocal recognition, with unidirectional recognition of the mother by offspring occurring in hiders and bidirectional recognition in followers. In domestic cattle, Bos taurus, a facultative hider species, vocal communication and recognition have not been studied in detail under free-ranging conditions, where cows and calves can graze …

Fallow Deer Polyandry Is Related To Fertilization Insurance, Elodie F. Briefer, Mary E. Farrell, Thomas J. Hayden, Alan G. Mcelligott

Alan G. McElligott, PhD

Polyandry is widespread, but its adaptive significance is not fully understood. The hypotheses used to explain its persistence have rarely been tested in the wild and particularly for large, long-lived mammals. We investigated polyandry in fallow deer, using female mating and reproduction data gathered over 10 years. Females of this species produce a single offspring (monotocous) and can live to 23 years old. Overall, polyandry was evident in 12 % of females and the long-term, consistent proportion of polyandrous females observed, suggests that monandry and polyandry represent alternative mating strategies. Females were more likely to be polyandrous when their first …

Quality Prevails Over Identity In The Sexually Selected Vocalisations Of An Ageing Mammal, Elodie F. Briefer, Elisabetta Vannoni, Alan G. Mcelligott

Alan G. McElligott, PhD

Background: Male sexually selected vocalisations generally contain both individuality and quality cues that are crucial in intra- as well as inter-sexual communication. As individuality is a fixed feature whereas male phenotypic quality changes with age, individuality and quality cues may be subjected to different selection pressures over time. Individuality (for example, morphology of the vocal apparatus) and quality (for example, body size and dominance status) can both affect the vocal production mechanism, inducing the same components of vocalisations to convey both kinds of information. In this case, do quality-related changes to the acoustic structure of calls induce a modification of …

Goats Learn Socially From Humans In A Spatial Problem-Solving Task, Christian Nawroth, Luigi Baciadonna, Alan G. Mcelligott

Alan G. McElligott, PhD

Domestication drives changes in animal cognition and behaviour. In particular, the capacity of dogs to socially learn from humans is considered a key outcome of how domestication shaped the canid brain. However, systematic evidence for social learning from humans in other domestic species is lacking and makes general conclusions about how domestication has affected cognitive abilities difficult. We assessed spatial and social problem-solving abilities in goats (Capra hircus) using a detour task, in which food was placed behind an inward or outward V-shaped hurdle. Goats performed better in the outward than in the inward detour without human demonstration. Importantly, a …

Emotions In Goats: Mapping Physiological, Behavioural And Vocal Profiles, Elodie F. Briefer, Federico Tettamanti, Alan G. Mcelligott

Alan G. McElligott, PhD

Emotions are important because they enable the selection of appropriate behavioural decisions in response to external or internal events. Techniques for understanding and assessing animal emotions, and particularly positive ones, are lacking. Emotions can be characterized by two dimensions: their arousal (bodily excitation) and their valence (negative or positive). Both dimensions can affect emotions in different ways. It is thus crucial to assess their effects on biological parameters simultaneously, so that accurate indicators of arousal and valence can be identified. To find convenient and noninvasive tools to assess emotions in goats, Capra hircus, we measured physiological, behavioural and vocal responses …

Goats Display Audience-Dependent Human-Directed Gazing Behaviour In A Problem-Solving Task, Christian Nawroth, Jemma M. Brett, Alan G. Mcelligott

Alan G. McElligott, PhD

Domestication is an important factor driving changes in animal cognition and behaviour. In particular, the capacity of dogs to communicate in a referential and intentional way with humans is considered a key outcome of how domestication as a companion animal shaped the canid brain. However, the lack of comparison with other domestic animals makes general conclusions about how domestication has affected these important cognitive features difficult. We investigated human-directed behaviour in an ‘unsolvable problem’ task in a domestic, but non-companion species: goats. During the test, goats experienced a forward facing or an away facing person. They gazed towards the forward …

Goats Favour Personal Over Social Information In An Experimental Foraging Task, Luigi Baciadonna, Alan G. Mcelligott, Elodie F. Briefer

Alan G. McElligott, PhD

Animals can use their environments more efficiently by selecting particular sources of information (personal or social), according to specific situations. Group-living animals may benefit from gaining information based on the behaviour of other individuals. Indeed, social information is assumed to be faster and less costly to use than personal information, thus increasing foraging efficiency. However, when food sources change seasonally or are randomly distributed, individual information may become more reliable than social information. The aim of this study was to test the use of conflicting personal versus social information in goats (Capra hircus), in a foraging task.We found that goats …

Fallow Bucks Attend To Vocal Cues Of Motivation And Fatigue, Benjamin J. Pitcher, Elodie F. Briefer, Elisabetta Vannoni, Alan G. Mcelligott

Alan G. McElligott, PhD

Vocalizations encode a range of information about the caller, and variation in calling behavior and vocal structure may provide listeners with information about the motivation and condition of the caller. Fallow bucks only vocalize during the breeding season and can produce more than 3000 groans per hour. Males modulate their calling rates, calling faster when other calling males and/or females are nearby. Groans also reveal caller fatigue, becoming shorter and higher pitched toward the end of the rut. Thus, fallow deer groans vary both over very short (minute to minute) and longer timescales (the rut). However, no studies have investigated …

Cross-Modal Recognition Of Familiar Conspecifics In Goats, Benjamin J. Pitcher, Elodie F. Briefer, Luigi Baciadonna, Alan G. Mcelligott

Alan G. McElligott, PhD

When identifying other individuals, animals may match current cues with stored information about that individual from the same sensory modality. Animals may also be able to combine current information with previously acquired information from other sensory modalities, indicating that they possess complex cognitive templates of individuals that are independent of modality. We investigated whether goats (Capra hircus) possess cross-modal representations (auditory–visual) of conspecifics. We presented subjects with recorded conspecific calls broadcast equidistant between two individuals, one of which was the caller. We found that, when presented with a stablemate and another herd member, goats looked towards the caller sooner and …

Artificial Neural Network Approach For Revealing Individuality, Group Membership And Age Information In Goat Kid Contact Calls, Livio Favaro, Elodie F. Briefer, Alan G. Mcelligott

Alan G. McElligott, PhD

Machine learning techniques are becoming an important tool for studying animal vocal communication. The goat (Capra hircus) is a very social species, in which vocal communication and recognition are important. We tested the reliability of a Multi-Layer Perceptron (feed-forward Artificial Neural Network, ANN) to automate the process of classification of calls according to individual identity, group membership and maturation in this species. Vocalisations were obtained from 10 half-sibling (same father but different mothers) goat kids, belonging to 3 distinct social groups. We recorded 157 contact calls emitted during first week, and 164 additional calls recorded from the same individuals at …

Assortative Mating In Fallow Deer Reduces The Strength Of Sexual Selection, Mary E. Farrell, Elodie Briefer, Alan G. Mcelligott

Alan G. McElligott, PhD

Background: Assortative mating can help explain how genetic variation for male quality is maintained even in highly polygynous species. Here, we present a longitudinal study examining how female and male ages, as well as male social dominance, affect assortative mating in fallow deer (Dama dama) over 10 years. Assortative mating could help explain the substantial proportion of females that do not mate with prime-aged, high ranking males, despite very high mating skew. We investigated the temporal pattern of female and male matings, and the relationship between female age and the age and dominance of their mates.

Results: The peak of …

Acoustic Analysis Of Cattle (Bos Taurus) Mother–Offspring Contact Calls From A Source–Filter Theory Perspective, Mónica Padilla De La Torre, Elodie F. Briefer, Tom Reader, Alan G. Mcelligott

Alan G. McElligott, PhD

Cattle vocalisations have been proposed as potential indicators of animal welfare. How-ever, very few studies have investigated the acoustic structure and information encoded in these vocalisations using advanced analysis techniques. Vocalisations play key roles in a wide range of communication contexts; e.g. for individual recognition and to help coordinate social behaviours. Two factors have greatly assisted our progress in developing an understanding of animal vocal communication. Firstly, more rigorous call analysis methods allow us to describe the variation in the vocal parameters in unprecedented detail. Secondly, the adoption of the “source–filter theory” of call production links the acoustic structure of …

Autonomic Nervous System Reactivity In A Free-Ranging Mammal: Effects Of Dominance Rank And Personality, Elodie F. Briefer, James A. Oxley, Alan G. Mcelligott

Alan G. McElligott, PhD

Modulation of the autonomic nervous system (ANS) activity allows animals to effectively respond to internal and external stimuli in everyday challenges via changes in, for example, heart and respiration rate. Various factors, ranging from social such as dominance rank to internal such as personality or affective states can impact animal physiology. Our knowledge of the combinatory effects of social and internal factors on ANS basal activity and reactivity, and of the importance that each factor has in determining physiological parameters, is limited, particularly in nonhuman, free-ranging animals. In this study, we tested the effects of dominance rank and personality (assessed …

Acoustic Divergence In The Rut Vocalizations Of Persian And European Fallow Deer, J. B. Stachowicz, E. Vannoni, B. J. Pitcher, Elodie F. Briefer, E. Geffen, A. G. Mcelligott

Alan G. McElligott, PhD

We conducted a study of the male rut vocalizations (groans) of two closely related species, Persian and European fallow deer. Persian fallow deer are endangered, restricted to Iran and Israel, and their rut vocalizations have never been studied. By contrast, European fallow deer are one of the most common deer species in the world, and have been the subject of numerous detailed studies. Persian bucks are approximately 16% larger than European bucks, and this can have important implications for vocalizations. Persian bucks were recorded in Israel, and European bucks were recorded in the UK and Ireland. We measured temporal, fundamental …