Discrimination of human and dog faces and inversion responses in domestic dogs (Canis familiaris)

Although domestic dogs can respond to many facial cues displayed by other dogs and humans, it remains unclear whether they can differentiate individual dogs or humans based on facial cues alone and, if so, whether they would demonstrate the face inversion effect, a behavioural hallmark commonly used in primates to differentiate face processing from object processing. In this study we first established the applicability of the Visual Paired Comparison (VPC or preferential looking) procedure for dogs using a simple object discrimination task with 2D pictures. The animals demonstrated a clear looking preference for novel objects when simultaneously presented with prior-exposed familiar objects. We then adopted this VPC procedure to assess their face discrimination and inversion responses. Dogs showed a deviation from random behaviour, indicating discrimination capability when inspecting upright dog faces, human faces and object images; but the pattern of viewing preference was dependent upon image category. They directed longer viewing time at novel (vs. familiar) human faces and objects, but not at dog faces, instead, a longer viewing time at familiar (vs. novel) dog faces was observed. No significant looking preference was detected for inverted images regardless of image category. Our results indicate that domestic dogs can use facial cues alone to differentiate individual dogs and humans, and that they exhibit a non-specific inversion response. In addition, the discrimination response by dogs of human and dog faces appears to differ with the type of face involved

Effects of food substrates on reliability of salivary cortisol measures in dogs in training context

Salivary cortisol has been widely used as a means of assessing stress in dogs (Beerda et al 1988; Schalke et al 2007), though several authors have questioned whether handling and the use of food/chews can affect measures (Kobelt et al 2003, Dreschel and Granger 2009). We investigated effects of food on salivary cortisol measures in a handling/training context. For the first study 10 dogs were used to investigate if food introduced unpredictable variation in salivary cortisol. For each dog tested, a control sample was taken, followed within 30 seconds by a sample with cheese (n equals 10), sausage (n equals 5) or chicken (n equals 5). Cortisol assayed with food tended to be lower (2.14 plus or minus 0.12ng/ml) than controls (2.59±0.23; t=2.08, p<0.05). This may be due to dilution of samples by greater production of fluid, or because food contamination reduces the efficacy of ELISA. There was a high positive correlation between the measures from cheese samples and their controls (Pearsons r equals 0.922, p smaller than 0.001), but no correlation with the sausage and chicken. In the second study, we used cheese to encourage salivation and 10 dogs were used to investigate changes in salivary cortisol following training. Dogs responded to three common vocal commands; “come”, “stay” and “leave”, together with a fourth command of the owner’s suggestion, each given by the owner, and by a person unfamiliar to the dog. Saliva was sampled before training, then at 10, 15, 20 and 25 minutes following start of training. There was no difference in salivary cortisol measures between samples, but a high concordance across samples (Kendall’s W=0.858, p<0.001). Our data suggests cheese does not introduce unpredictable variation in salivary cortisol measures, and consequently may be a more appropriate aid to encourage salivation than sausage, chicken or meat flavoured rope (Dreschel and Granger 2009). Beerda, B et al 1998. Applied Animal Behaviour Science. 58:365-381 Dreschel, NA and Granger DA 2009. Hormones and Behavior, 55:163-168. Kobelt, AJ et al 2003. Research in Veterinary Science. 75:157-161. Schalke E et al 2007. Applied Animal Behaviour Science. 105:369-38

Dairy calves' personality traits predict social proximity and response to an emotional challenge

Abstract The assessment of individual traits requires that tests are reliable (i.e. consistency over time) and externally valid, meaning that they predict future responses in similar contexts (i.e. convergent validity) but do not predict responses to unrelated situations (i.e. discriminant validity). The aim of this study was to determine if dairy calf personality traits (Fearfulness, Sociability and Pessimism), derived from behaviours expressed in standardized tests, predict individuals’ responses in related situations. The first experiment tested if the trait ‘Sociability’ was related to the expression of social behaviour in the home-pen, with calves assigned individual proximity scores (based on proximity to other calves) while they were in their home-pen at approximately 113 and 118 d of age. The second experiment aimed at exploring whether traits ‘Fearfulness’ and ‘Pessimism’ were related to the calves’ emotional response to transportation. All calves were subjected to two 10-min transportation challenges done on two consecutive days. Emotional response was assessed using the maximum eye temperature (measured using infrared thermography) and the number of vocalizations emitted. Social proximity scores (Experiment 1), vocalizations emitted and maximum eye temperature after loading (Experiment 2) were consistent over time. In addition, the results showed good convergent validity with calves scoring higher in Sociability also having higher proximity scores in the home-pen, and animals scoring higher in Fearfulness and Pessimism showing a more intense emotional response to transportation. The results also showed good discriminant validity, as neither Fearfulness nor Pessimism were associated with the expression of social behaviours (Experiment 1) and Sociability was not associated with the animal’s emotional response to transportation (Experiment 2). We conclude that the methodology used to measure personality traits shows good reliability and external validity

Factors Influencing Individual Variation in Farm Animal Cognition and How to Account for These Statistically

For farmed species, good health and welfare is a win-win situation: both the animals and producers can benefit. In recent years, animal welfare scientists have embraced cognitive sciences to rise to the challenge of determining an animal's internal state in order to better understand its welfare needs and by extension, the needs of larger groups of animals. A wide range of cognitive tests have been developed that can be applied in farmed species to assess a range of cognitive traits. However, this has also presented challenges. Whilst it may be expected to see cognitive variation at the species level, differences in cognitive ability between and within individuals of the same species have frequently been noted but left largely unexplained. Not accounting for individual variation may result in misleading conclusions when the results are applied both at an individual level and at higher levels of scale. This has implications both for our fundamental understanding of an individual's welfare needs, but also more broadly for experimental design and the justification for sample sizes in studies using animals. We urgently need to address this issue. In this review, we will consider the latest developments on the causes of individual variation in cognitive outcomes, such as the choice of cognitive test, sex, breed, age, early life environment, rearing conditions, personality, diet, and the animal's microbiome. We discuss the impact of each of these factors specifically in relation to recent work in farmed species, and explore the future directions for cognitive research in this field, particularly in relation to experimental design and analytical techniques that allow individual variation to be accounted for appropriately

Mécanismes et bases sensorielles de la discrimination sociale entre jeunes chez les ovins: étude comportementale

*INRA Bibliothèque PRC -37380 Nouzilly (FRA) Diffusion du document : INRA Bibliothèque PRC -37380 Nouzilly (FRA) Diplôme : Dr. d'Universit

The role of visual cues in lambs'discrimination between individual agemates

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Social discrimination in lambs : the role of indirect familiarization and methods of assessment

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La reconnaissance sociale chez les mammifères : mécanismes et bases sensorielles impliquées

National audienceSocial recognition plays a major role in the mediation of interactions between individuals and the organisation of societies. During the last 20 years, numerous studies have investigated the adaptive significance, underlying mechanisms and sensory basis of individual recognition of kin as well as non-kin. The results indicate that the recognition of conspecifics involves complex, flexible processes that are widespread throughout the vertebrate kingdom. Such recognition can be based upon different mechanisms and sensory modalities, and influenced by diverse factors. Learned phenotypic traits of conspecifics through familiarisation, including oneself, is the fundamental mechanism implicated in recognition. Animals become directly familiar with others with which they interact. Moreover, kin of familiar conspecifics may be discriminated because of their resemblance to the known individuals. An animal's genotype and environmental variables may both contribute to its recognisable individual signatures (e.g. distinctive olfactory, visual, or auditory characteristics). In general, the study of social recognition enhances our understanding of the cognitive world of animals.La reconnaissance sociale tient une grande place dans les interactions entre individus et donc dans l’organisation en société. La reconnaissance des individus apparentés ou non a suscité depuis les années 80 de nombreuses études portant sur les avantages adaptatifs ainsi que sur les mécanismes et bases sensorielles sur lesquels elle est basée. Ces travaux ont révélé que la reconnaissance sociale est un processus complexe et non rigide très largement répandu chez les Vertébrés. Elle peut en effet reposer sur différents mécanismes et bases sensorielles non mutuellement exclusifs et être influencée par divers facteurs. La familiarisation est le mécanisme fondamental de la reconnaissance. Elle permet l’apprentissage d’indices phénotypiques provenant des congénères ou de soi. Les apparentés de ces individus familiers peuvent également être reconnus du fait de leurs ressemblances avec ces derniers. Les indices phénotypiques qui servent de base à la reconnaissance peuvent appartenir à différentes modalités sensorielles comme l’olfaction, la vision ou l’audition et être modelés par le génome et l’environnement. De façon générale l’étude de la reconnaissance sociale permet d’avoir une meilleure connaissance du monde cognitif des animaux

Effect of maternal presence on the development of social relationships among lambs

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Vocal discrimination of kin and non-kin agemates among lambs

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