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Caldwell, C. A., & Whiten, A. (2002). Evolutionary perspectives on imitation: is a comparative psychology of social learning possible? Anim. Cogn., 5(4), 193–208.
Abstract: Studies of imitation in animals have become numerous in recent times, but do they contribute to a comparative psychology of social learning? We review this burgeoning field to identify the problems and prospects for such a goal. Difficulties of two main kinds are identified. First, researchers have tackled questions about social learning from at least three very different theoretical perspectives, the “phylogenetic”, “animal model”, and “adaptational”. We examine the conflicts between them and consider the scope for integration. A second difficulty arises in the methodological approaches used in the discipline. In relation to one of these – survey reviews of published studies – we tabulate and compare the contrasting conclusions of nine articles that together review 36 studies. The basis for authors' disagreements, including the matters of perceptual opacity, novelty, sequential structure, and goal representation, are examined. In relation to the other key method, comparative experimentation, we identify 12 studies that have explicitly compared species' imitative ability on similar tasks. We examine the principal problems of comparing like with like in these studies and consider solutions, the most powerful of which we propose to be the use of a systematic range of task designs, rather than any single “gold standard” task.
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Heschl, A., & Burkart, J. (2006). A new mark test for mirror self-recognition in non-human primates. Primates, 47(3), 187–198.
Abstract: For 30 years Gallup's (Science 167:86-87, 1970) mark test, which consists of confronting a mirror-experienced test animal with its own previously altered mirror image, usually a color mark on forehead, eyebrow or ear, has delivered valuable results about the distribution of visual self-recognition in non-human primates. Chimpanzees, bonobos, orangutans and, less frequently, gorillas can learn to correctly understand the reflection of their body in a mirror. However, the standard version of the mark test is good only for positively proving the existence of self-recognition. Conclusive statements about the lack of self-recognition are more difficult because of the methodological constraints of the test. This situation has led to a persistent controversy about the power of Gallup's original technique. We devised a new variant of the test which permits more unequivocal decisions about both the presence and absence of self-recognition. This new procedure was tested with marmoset monkeys (Callithrix jacchus), following extensive training with mirror-related tasks to facilitate performance in the standard mark test. The results show that a slightly altered mark test with a new marking substance (chocolate cream) can help to reliably discriminate between true negative results, indicating a real lack of ability to recognize oneself in a mirror, from false negative results that are due to methodological particularities of the standard test. Finally, an evolutionary hypothesis is put forward as to why many primates can use a mirror instrumentally – i.e. know how to use it for grasping at hidden objects – while failing in the decisive mark test.
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Viscido, S. V., Miller, M., & Wethey, D. S. (2002). The dilemma of the selfish herd: the search for a realistic movement rule. J. Theor. Biol., 217(2), 183–194.
Abstract: The selfish herd hypothesis predicts that aggregations form because individuals move toward one another to minimize their own predation risk. The “dilemma of the selfish herd” is that movement rules that are easy for individuals to follow, fail to produce true aggregations, while rules that produce aggregations require individual behavior so complex that one may doubt most animals can follow them. If natural selection at the individual level is responsible for herding behavior, a solution to the dilemma must exist. Using computer simulations, we examined four different movement rules. Relative predation risk was different for all four movement rules (p<0.05). We defined three criteria for measuring the quality of a movement rule. A good movement rule should (a) be statistically likely to benefit an individual that follows it, (b) be something we can imagine most animals are capable of following, and (c) result in a centrally compact flock. The local crowded horizon rule, which allowed individuals to take the positions of many flock-mates into account, but decreased the influence of flock-mates with distance, best satisfied these criteria. The local crowded horizon rule was very sensitive to the animal's perceptive ability. Therefore, the animal's ability to detect its neighbors is an important factor in the dynamics of group formation.
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West, R. E., & Young, R. J. (2002). Do domestic dogs show any evidence of being able to count? Anim. Cogn., 5(3), 183–186.
Abstract: Numerical competence has been demonstrated in a wide range of animal species. The level of numerical abilities shown ranges from simple relative numerousness judgements to true counting. In this study we used the preferential looking technique to test whether 11 pet dogs could count. The dogs were presented with three simple calculations: “1+1=2”; “1+1=1”; and “1+1=3”. These calculations were performed by presenting the dogs with treats that were placed behind a screen that allowed manipulation of the outcome of the calculation. When the dogs expected the outcome they spent the same amount of time looking at the result of the calculation as they did on the initial presentation. However, when the result was unexpected dogs spent significantly longer looking at the outcome of the calculation. The results suggest that the dogs were anticipating the outcome of the calculations they observed, thus suggesting that dogs may have a rudimentary ability to count.
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Dugatkin, L. A., & Godin, J. G. (1992). Reversal of female mate choice by copying in the guppy (Poecilia reticulata). Proc Biol Sci, 249(1325), 179–184.
Abstract: Ever since Fisher (1958) formalized models of sexual selection, female mate choice has been assumed to be a genetically determined trait. Females, however, may also use social cues to select mates. One such cue might be the mate choice of conspecifics. Here we report the first direct evidence that a female's preference for a particular male can in fact be reversed by social cues. In our experiments using the Trinidadian guppy (Poecilia reticulata), this reversal was mediated by mate-copying opportunities, such that a female (the 'focal' female) is given the opportunity to choose between two males, followed by a period in which she observes a second female (the 'model' female) displaying a preference for the male she herself did not prefer initially. When allowed to choose between the same males a second time, compared with control tests, a significant proportion of focal females reversed their mate choice and copied the preference of the model female. These results provide strong evidence for the role of non-genetic factors in sexual selection and underlie the need for new models of sexual selection that explicitly incorporate both genetic and cultural aspects of mate choice.
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McClure, S. R., & Chaffin, M. K. (1993). Self-mutilative behavior in horses. J Am Vet Med Assoc, 202(2), 179–180.
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Pepperberg, I. M. (2002). The value of the Piagetian framework for comparative cognitive studies. Anim. Cogn., 5(3), 177–182.
Abstract: Although the Piagetian framework has been used by numerous researchers to compare cognitive abilities of diverse species, the system is often criticized as implemented. I examine the various criticisms, suggest ways in which the system can be improved, and argue for the need for descriptive systems such as the Piagetian framework to complement programs that look for cellular and molecular bases or mathematical models to explain behavior.
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Visser, E. K., Van Reenen, C. G., Rundgren, M., Zetterqvist, M., Morgan, K., & Blokhuis, H. J. (2003). Responses of horses in behavioural tests correlate with temperament assessed by riders. Equine Vet J, 35(2), 176–183.
Abstract: REASONS FOR PERFORMING STUDY: Behavioural tests as well as observers' ratings have been used to study horses' temperament. However, the relationship between the ratings and the responses in behavioural tests has not yet been studied in detail. OBJECTIVES: The aim of the present study was to examine this relationship between ratings and responses. METHODS: Eighteen mature Swedish Warmblood horses were subjected to 2 behavioural tests, one relating to novelty (novel object test) and one to handling (handling test). Subsequently, 16 of these horses were ridden by 16 equally experienced students, having no former experience with the horses. Immediately after each ride, the students scored the horse for 10 temperamental traits using a line rating method. RESULTS: It was shown that for each temperamental trait all 16 riders agreed on the ranking of the horses (0.212<W<0.505, P < 0.001). CONCLUSIONS: Correlations between behavioural and heart rate variables in the behavioural tests revealed that horses with a high level of locomotion or much restlessness behaviour exhibited high mean heart rate and low heart rate variability. In particular, heart rate variables in the behavioural tests were found to correlate with riders' rating scores. Furthermore, the underlying components of the handling test, retrieved with a principal component analysis (PCA) correlated with riders' rating scores while the underlying components of the novel object test did not. POTENTIAL CLINICAL RELEVANCE: It is concluded that it is possible for a large panel of assessors to agree upon a horse's temperament and that objective measures from behavioural tests correlate significantly with temperamental traits assessed by a panel of assessors.
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Ricard, A., & Chanu, I. (2001). Genetic parameters of eventing horse competition in France. Genet Sel Evol, 33(2), 175–190.
Abstract: Genetic parameters of eventing horse competitions were estimated. About 13 000 horses, 30 000 annual results during 17 years and 110 000 starts in eventing competitions during 8 years were recorded. The measures of performance were logarithmic transformations of annual earnings, annual earnings per start, and annual earnings per place, and underlying variables responsible for ranks in each competition. Heritabilities were low (0.11 / 0.17 for annual results, 0.07 for ranks). Genetic correlations between criteria were high (greater than 0.90) except between ranks and earnings per place (0.58) or per start (0.67). Genetic correlations between ages (from 5 to 10 years old) were also high (more than 0.85) and allow selection on early performances. The genetic correlation between the results in different levels of competition (high/international and low/amateur) was near 1. Genetic correlations of eventing with other disciplines, which included partial aptitude needed for eventing, were very low for steeplechase races (0.18) and moderate with sport: jumping (0.45), dressage (0.58). The results suggest that selection on jumping performance will lead to some positive correlated response for eventing performance, but much more response could be obtained if a specific breeding objective and selection criteria were developed for eventing.
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Zentall, T. R. (2006). Mental time travel in animals: a challenging question. Behav. Process., 72(2), 173–183.
Abstract: Humans have the ability to mentally recreate past events (using episodic memory) and imagine future events (by planning). The best evidence for such mental time travel is personal and thus subjective. For this reason, it is particularly difficult to study such behavior in animals. There is some indirect evidence, however, that animals have both episodic memory and the ability to plan for the future. When unexpectedly asked to do so, animals can report about their recent past experiences (episodic memory) and they also appear to be able to use the anticipation of a future event as the basis for a present action (planning). Thus, the ability to imagine past and future events may not be uniquely human.
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