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Clucas, B., Marzluff, J. M., Mackovjak, D., & Palmquist, I. (2013). Do American Crows Pay Attention to Human Gaze and Facial Expressions? Ethology, 119(4), 296–302.
Abstract: Interactions between species can lead to the evolution of interspecific communication. Non-verbal communication by humans, both intentional and unintentional, can be interpreted by other species. We tested whether American crows (Corvus brachyrhynchos) were sensitive to human facial features under field conditions by comparing flight initiation distances and urgency of escape behavior to human approaches varying in eye contact and facial expression. We first examined whether crows distinguish between an approaching human who is directly gazing at them and a human approaching them with an averted gaze. In a second experiment, we tested whether crows differentiate a smiling from scowling human approaching them with direct or averted gaze. In the first experiment, we found that crows fled sooner and more urgently when humans were directly gazing at them. Similarly, in the second experiment, crows responded sooner to a direct vs. averted gaze; however, they did not react differently to varying human facial expressions. We suggest that crows use human gaze as a reliable visual cue compared with facial expressions when making decisions about responding to approaching humans. This is the first study to show that a wild corvid species changes its behavior based on human gaze, possibly representing an adaptation to living in human-dominated urban areas and suggesting crows might perceive human intention by this visual cue.
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Cochet, H., & Byrne, R. W. (2013). Evolutionary origins of human handedness: evaluating contrasting hypotheses. Animal Cognition, 16(4), 531–542.
Abstract: Variation in methods and measures, resulting in past dispute over the existence of population handedness in nonhuman great apes, has impeded progress into the origins of human right-handedness and how it relates to the human hallmark of language. Pooling evidence from behavioral studies, neuroimaging and neuroanatomy, we evaluate data on manual and cerebral laterality in humans and other apes engaged in a range of manipulative tasks and in gestural communication. A simplistic human/animal partition is no longer tenable, and we review four (nonexclusive) possible drivers for the origin of population-level right-handedness: skilled manipulative activity, as in tool use; communicative gestures; organizational complexity of action, in particular hierarchical structure; and the role of intentionality in goal-directed action. Fully testing these hypotheses will require developmental and evolutionary evidence as well as modern neuroimaging data.
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Pelé, M., & Sueur, C. (2013). Decision-making theories: linking the disparate research areas of individual and collective cognition. Animal Cognition, 16(4), 543–556.
Abstract: In order to maximize their fitness, animals have to deal with different environmental and social factors that affect their everyday life. Although the way an animal behaves might enhance its fitness or survival in regard to one factor, it could compromise them regarding another. In the domain of decision sciences, research concerning decision making focuses on performances at the individual level but also at the collective one. However, between individual and collective decision making, different terms are used resulting in little or no connection between both research areas. In this paper, we reviewed how different branches of decision sciences study the same concept, mainly called speed-accuracy trade-off, and how the different results are on the same track in terms of showing the optimality of decisions. Whatever the level, individual or collective, each decision might be defined with three parameters: time or delay to decide, risk and accuracy. We strongly believe that more progress would be possible in this domain of research if these different branches were better linked, with an exchange of their results and theories. A growing amount of literature describes economics in humans and eco-ethology in birds making compromises between starvation, predation and reproduction. Numerous studies have been carried out on social cognition in primates but also birds and carnivores, and other publications describe market or reciprocal exchanges of commodities. We therefore hope that this paper will lead these different areas to a common decision science.
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Morton, F. B., Lee, P. C., & Buchanan-Smith, H. M. (2013). Taking personality selection bias seriously in animal cognition research: a case study in capuchin monkeys (Sapajus apella). Animal Cognition, 16(4), 677–684.
Abstract: In most experimental work on animal cognition, researchers attempt to control for multiple interacting variables by training subjects prior to testing, allowing subjects to participate voluntarily, and providing subjects with food rewards. However, do such methods encourage selection bias from subjects’ personalities? In this study, we trained eighteen zoo-housed capuchin monkeys (Sapajus apella) for two experiments, under conditions of positive reinforcement (i.e. food rewards) and free-choice participation. Using a combination of behavioral and rater-based methods, we identified and validated five personality dimensions in these capuchins (Assertiveness, Openness, Neuroticism, Sociability, and Attentiveness). Scores on Openness were positively related to individual differences in monkey task participation, reflecting previous work showing that such individuals are often more active, curious, and willing to engage in testing. We also found a negative relationship between scores on Assertiveness and performance on tasks, which may reflect the trade-offs between speed and accuracy in these animals’ decision-making. Highly Assertive individuals (the most sociable within monkey groups) may also prioritize social interactions over engaging in research. Lastly, monkeys that consistently participated and performed well on both tasks showed significantly higher Openness and lower Assertiveness compared to others, mirroring relationships found between personality, participation, and performance among all participants. Participation and performance during training was clearly biased toward individuals with particular personalities (i.e. high Openness, low Assertiveness). Results are discussed in light of the need for careful interpretation of comparative data on animal cognition and the need for researchers to take personality selection bias more seriously.
Animal Cognition Animal Cognition Look
Inside
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Flauger, B., & Krueger, K. (2013). Aggressionslevel und Platzangebot bei Pferden (Equus caballus) [ Aggression level and enclosure size in horses (Equus caballus)]. Pferdeheilkunde, 29(4), 495–504.
Abstract: Viele Pferdebesitzer bevorzugen aus Angst vor aggressiven Interaktionen und Verletzungsgefahr der Tiere untereinander die Einzelhaltung, obwohl von Tierschutzorganisationen die Gruppenhaltung für Pferde empfohlen wird. In dieser Studie beobachteten wir während des alltäglichen Soziallebens als auch bei der Eingliederung von neuen Gruppenmitgliedern das Sozialverhalten, insbesondere das Aggressionsverhalten, von elf Gruppen domestizierter Pferde (Equus caballus) verschiedener Größe und Zusammensetzung. Während des alltäglichen Soziallebens hatten die Gruppe und der Paddock-Typ (Gras / kein Gras) keinen Einfluss auf die Verhaltensweisen, wohingegen die Paddockgröße unter 10000 m2 einen signifikanten Einfluss auf die submissiven Verhaltensweisen (GzLM; n=56; t=-2.061, P=0.044) und einen nicht signifikanten Einfluss auf die aggressiven Verhaltensweisen (GzLM; n=56; t=-1.782, P=0.081) hatte. Allerdings verringerten sich sowohl die aggressiven als auch die submissiven Verhaltensweisen mit steigendem Platzangebot bis zu 10000 m2 (Spearman rank Korrelation; n=56; aggressive Verhaltensweisen: r = -0.313, P = 0.019; submissive Verhaltensweisen: r = -0.328, P = 0.014). Während den Eingliederungen reduzierten sich die Aggressionen pro Stunde mit der Vergrößerung des Platzangebotes (Spearman rank Korrelation; n=28; r=-0.402, P=0.034). Dies zeigte sich noch deutlicher, wenn Beobachtungen mit einem Platzangebot von über 10000 m2 ausgeschlos- sen wurden (Spearman rank Korrelation; n=23; r=-0.549, P=0.007). Während des alltäglichen Soziallebens näherte sich der Aggressionslevel der Nulllinie an, wenn das Platzangebot pro Pferd mehr als 331 m2 betrug. Deshalb empfehlen wir zur Reduzierung des Aggressionslevels und des Verletzungsrisikos von sozial gehaltenen Pferdegruppen ein Platzangebot von mindestens 331 m2 pro Pferd.
[Even though animal welfare organisations propose group housing for horse welfare, many owners stable horses individually for fear of aggressive interactions and injury risks. In the present study we observed social behaviour, and especially aggressiveness, in eleven domestic horse groups (Equus caballus) of different size and composition, in basic social situations and when new group members were introduced. During basic social situations, the group and the type of paddock (grass / no grass) had no effect on any of the behaviours, where- as the enclosure size below 10,000 m2 had a significant effect on submissive behaviour (GzLM; n=56; t=-2.061, P=0.044) and an insignificant effect on aggressive behaviour (GzLM; n=56; t=-1.782, P=0.081). However, aggressive and submissive behaviour dimi- nished with the increase of enclosure sizes up to 10,000 m2 (Spearman rank correlation; n = 56; aggressive behaviour: r = -0.313, P=0.019; submissive behaviour: r=-0.328, P=0.014). During introductions, aggression levels per hour decreased with any increase of enclosure size (Spearman rank correlation; n=28; r=-0.402, P=0.034) and even more when enclosure sizes above 10,000 m2 were excluded (Spearman rank correlation; n=23; r=-0.549, P=0.007). During basic social situations the aggression level approached zero when the space allowance was more than 331 m2 per horse. We therefore recommend keeping horse groups in an enclosure with at least 331 m2 per horse to reduce aggression and injuries.]
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Calcagnoli, F., Boer, S. F., Althaus, M., Boer, J. A., & Koolhaas, J. M. (2013). Antiaggressive activity of central oxytocin in male rats. Psychopharmacology, 229(4), 639–651.
Abstract: Rationale A substantial body of research suggests that the
neuropeptide oxytocin promotes social affiliative behaviors
in a wide range of animals including humans. However, its
antiaggressive action has not been unequivocally demonstrated
in male laboratory rodents.
Objective Our primary goal was to examine the putative
serenic effect of oxytocin in a feral strain (wild type
Groningen, WTG) of rats that generally show a much
broader variation and higher levels of intermale aggression
than commonly used laboratory strains of rats.
Methods Resident animals were intracerebroventricularly
(icv) administered with different doses of synthetic oxytocin
and oxytocin receptor antagonist, alone and in combination,
in order to manipulate brain oxytocin functioning and to
assess their behavioral response to an intruder.
Results Our data clearly demonstrate that acute icv administered
oxytocin produces dose-dependent and receptorselective
changes in social behavior, reducing aggression
and potentiating social exploration. These antiaggressive
effects are stronger in the more offensive rats. On the other
hand, administration of an oxytocin receptor antagonist
tends to increase (nonsignificantly) aggression only in
low–medium aggressive animals.
Conclusions These results suggest that transiently enhancing
brain oxytocin function has potent antiaggressive effects,
whereas its attenuation tends to enhance aggressiveness. In
addition, a possible inverse relationship between trait aggression
and endogenous oxytocinergic signaling is revealed.
Overall, this study emphasizes the importance of brain
oxytocinergic signaling for regulating intermale offensive aggression.
This study supports the suggestion that oxytocin
receptor agonists could clinically be useful for curbing heightened
aggression seen in a range of neuropsychiatric disorders
like antisocial personality disorder, autism, and addiction.
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Pirault, P., Danvy, S., Verrier, E., & Leroy, G. (2013). Genetic Structure and Gene Flows within Horses: A Genealogical Study at the French Population Scale. Plos One, 8(4), e61544.
Abstract: Since horse breeds constitute populations submitted to variable and multiple outcrossing events, we analyzed the genetic structure and gene flows considering horses raised in France. We used genealogical data, with a reference population of 547,620 horses born in France between 2002 and 2011, grouped according to 55 breed origins. On average, individuals had 6.3 equivalent generations known. Considering different population levels, fixation index decreased from an overall species FIT of 1.37%, to an average of -0.07% when considering the 55 origins, showing that most horse breeds constitute populations without genetic structure. We illustrate the complexity of gene flows existing among horse breeds, a few populations being closed to foreign influence, most, however, being submitted to various levels of introgression. In particular, Thoroughbred and Arab breeds are largely used as introgression sources, since those two populations explain together 26% of founder origins within the overall horse population. When compared with molecular data, breeds with a small level of coancestry also showed low genetic distance; the gene pool of the breeds was probably impacted by their reproducer exchanges.
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Silk, J., Cheney, D., & Seyfarth, R. (2013). A practical guide to the study of social relationships. Evol. Anthropol., 22(5), 213–225.
Abstract: Behavioral ecologists have devoted considerable effort to identifying the sources of variation in individual reproductive success. Much of this work has focused on the characteristics of individuals, such as their sex and rank. However, many animals live in stable social groups and the fitness of individuals depends at least in part on the outcome of their interactions with other group members. For example, in many primate species, high dominance rank enhances access to resources and reproductive success. The ability to acquire and maintain high rank often depends on the availability and effectiveness of coalitionary support. Allies may be cultivated and coalitions may be reinforced by affiliative interactions such as grooming, food sharing, and tolerance. These findings suggest that if we want to understand the selective pressures that shape the social behavior of primates, it will be profitable to broaden our focus from the characteristics of individuals to the properties of the relationships that they form with others. The goal of this paper is to discuss a set of methods that can be used to quantify the properties of social relationships.
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Siniscalchi, M., Cirone, F., Guaricci, A. C., & Quaranta, A. (2013). Catecholamine plasma levels, IFN-γ serum levels and antibodies production induced by rabies vaccine in dogs selected for their paw preference. Laterality: Asymmetries of Body, Brain and Cognition, 19(5), 522–532.
Abstract: To explore the possible role of the sympathetic nervous activity in the asymmetrical crosstalk between the brain and immune system, catecholamine (E, NE) plasma levels, Interferon-? (IFN-?) serum levels and production of antibodies induced by rabies vaccine in dogs selected for their paw preference were measured. The results showed that the direction of behavioural lateralization influenced both epinephrine levels and immune response in dogs. A different kinetic of epinephrine levels after immunization was observed in left-pawed dogs compared to both right-pawed and ambidextrous dogs. The titers of antirabies antibodies were lower in left-pawed dogs than in right-pawed and ambidextrous dogs. Similarly, the IFN-? serum levels were lower in left-pawed dogs than in the other two groups. Taken together, these findings showed that the left-pawed group appeared to be consistently the different group stressing the fundamental role played by the sympathetic nervous system as a mechanistic basis for the crosstalk between the brain and the immune system.
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Graf, P., König von Borstel, U., & Gauly, M. (2013). Importance of personality traits in horses to breeders and riders. Journal of Veterinary Behavior: Clinical Applications and Research, 8(5), 316–325.
Abstract: Abstract Especially in horses, personality traits play an important role because horses' behavior influences their quality as a riding partner. In contrast to that, no objective assessment of horses' personality traits is available at present. Although initial efforts are made in this field, a successful implementation of behavior tests into horse performance tests depends on the acceptance of the riders and breeders. Therefore, the aim of the present study was to assess the importance of personality traits to breeders and riders as well as the degree of riders' acceptance of a temperament test as a more objective means of assessing equine personality traits. Using a web-based survey consisting of a 41-item questionnaire, a total of 1087 competition riders (49.3%), breeders (39.0%), leisure riders (37.9%), and professional riders (8.6%) of 13 countries were recruited to participate in the survey. When asked to split 1000 Euro among the different traits listed in the breeding goal, respondents clearly assigned more weight to the personality-related character and temperament traits (least squares mean ± standard error; P < 0.005: €228.7 ± 17.6) and willingness to work (€123.0 ± 9.6) compared with performance traits, such as the quality of trot (€77.7 ± 6.9) or show jumping (€68.0 ± 12.3). Nevertheless, expected differences in relative weighting of traits between the different groups of riders were confirmed (e.g., character and temperament: €209.3 ± 6.1 [leisure riders] vs. €149.7 ± 5.4 [competition riders], P < 0.0001). When asking why personality traits are so important, the simplification of daily work with the horses (47.9%) and relationship between horse and human (44.9%) as well as a more comfortable and safer handling (31.5%) were most commonly listed. As much as 45.6% of all participants see quality problems with the current assessment and suggested the evaluation of all breeding animals (30.1%), followed by a better standardization of assessment procedures (25.5%) and a move to more objective criteria such as the introduction of a temperament test (20.3%) for solving the problems. The present survey revealed that behavior traits are very important to all groups of riders and breeders, although there are diverse opinions about it. According to the participants, there is a need for and a high potential in the move toward more objective assessment methods of horses' personality traits, and participants would support a restructuring of the current assessment.
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