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Dawkins, M. S. (2001). Who Needs Consciousness? Animal Welfare, 10, 19–29.
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Dawson, B. V., & Foss, B. M. (1965). Observational learning in budgerigars. Anim. Behav., 13(4), 470–474.
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Day, R. L., Coe, R. L., Kendal, J. R., & Laland, K. N. (2003). Neophilia, innovation and social learning: a study of intergeneric differences in callitrichid monkeys. Anim. Behav., 65(3), 559–571.
Abstract: In a comparative study of neophilia, innovation and social attentiveness we exposed individuals in seven callitrichid species, from three genera, to novel extractive foraging tasks. The results revealed consistently shorter response latencies, higher levels of successful and unsuccessful manipulation, and greater attentiveness to the task and to conspecifics inLeontopithecus (lion tamarins) than in both Saguinus (tamarins) and Callithrix (marmosets). This is consistent with the hypothesis that species dependent upon manipulative and explorative foraging tend to be less neophobic and more innovative than other species. Furthermore, Callithrix appeared to be less neophobic than Saguinus; ifCallithrix is regarded as the greater specialist, this result is inconsistent with the hypothesis that neophobia is associated with foraging specialization. We consider the relevance of our findings to taxonomic relationships, and to technical and Machiavellian intelligence hypotheses and discuss the implications for captive breeding and reintroduction strategies.Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.
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de Latude, M., Demange, M., Bec, P., & Blois-Heulin, C. (2009). Visual laterality responses to different emotive stimuli by red-capped mangabeys, Cercocebus torquatus torquatus. Anim. Cogn., 12(1), 31–42.
Abstract: Abstract: Hemispheric asymmetry in emotional perception has been put forward by different theories as the right hemisphere theory or the valence theory. But no consensus was found about the role played by both hemispheres. So, in order to test the different theories, we investigated preferential use of one eye in red-capped mangabeys, at the individual as well as at the group level. In this study we investigated the influence of the emotional value of stimuli on the direction and strength of visual preference of 14 red-capped mangabeys. Temporal stability of the bias of use of a given eye was evaluated by comparing our current results to those obtained 2.5 months previously. Two experimental devices, a tube and a box, tested five different stimuli: four food types varying in palatability and a neutral stimulus. The subjects" food preferences were evaluated before testing the laterality. The mangabeys used their left eyes predominantly at the group level for the tube task. The majority of the subjects showed a visual preference at the individual level for the box task, but this bias was not present at the group level. As the palatability of the stimuli increased, the number of lateralized subjects and the number of subjects using preferentially their left eye increased. Similarly, the strength of laterality was related to food preference. Strength of laterality was significantly higher for subjects using their left eye than for subjects using their right eye. Preferential use of a given eye was stable over short periods 2.5 months later. Our data agree with reports on visual laterality for other species. Our results support the valence theory of a hemispheric sharing of control of emotions in relation to their emotional value.
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De Lillo,, C. De Lillo, Floreano,, D. Floreano, Antinucci,, & F. Antinucci. (2001). Transitive choices by a simple, fully connected, backpropagation neural network: implications for the comparative study of transitive inference. Anim. Cogn., 4(1), 61–68.
Abstract: In search of the minimal requirements for transitive reasoning, a simple neural network was trained and tested on the non-verbal version of the conventional “five-term-series task” – a paradigm used with human adults, children and a variety of non-human species. The transitive performance of the network was analogous in several aspects to that reported for children and animals. The three effects usually associated with transitive choices i.e. “symbolic distance”, “lexical marking” and “end-anchor”, were also clearly shown by the neural network. In a second experiment, where the training conditions were manipulated, the network failed to match the behavioural pattern reported for human adults in the test following an ordered presentation of the premises. However, it mimicked young children's performance when tested with a novel comparison term. Although we do not intend to suggest a new model of transitive inference, we conclude, in line with other authors, that a simple error-correcting rule can generate transitive behaviour similar to the choice pattern of children and animals in the binary form of the five-term-series task without requiring high-order logical or paralogical abilities. The analysis of the training history and of the final internal structure of the network reveals the associative strategy employed. However, our results indicate that the scope of the associative strategy used by the network might be limited. The extent to which the conventional five-term-series task, in absence of appropriate manipulations of training and testing conditions, is suitable to detect cognitive differences across species is also discussed on the basis of our results.
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de Vries, H. (1995). An improved test of linearity in dominance hierarchies containing unknown or tied relationships. Anim. Behav., 50(5), 1375–1389.
Abstract: Appleby (1983, Anim. Behav., 31, 600-608) described a statistical test, based on the work of Kendall (1962, Rank Correlation Methods), for the significance of linearity in dominance hierarchies. He suggested that unknown relationships should be assigned the value 1/2 and that subsequently the same test procedure can be used. In this paper it is shown that incorrect results are obtained by this method whenever there are unknown relationships. Values of the linearity index are systematically too low. P-values can be too high (underestimating the significance) or too low (overestimating), and seem to differ by not much more than a factor two (respectively a half) from the correct P-value. An improved method is developed for testing linearity in a set of dominance relationships containing unknown relationships. Furthermore, it is argued that, if one admits the possibility of tied dominance relationships, which should indeed be assigned the value 1/2, Landau's linearity index is to be preferred to Kendall's index. A randomization test is developed for assessing the significance of linearity or non-linearity in a set of dominance relationships containing unknown or tied relationships. The test statistic employed in this testing procedure is based on Landau's linearity index, but takes the unknown and tied relationships into account.
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De Vries, H., & Appleby, M. C. (2000). Finding an appropriate order for a hierarchy: a comparison of the I&SI and the BBS methods. Anim. Behav., 59(1), 239–245.
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de Vries, H., Stevens, J. M. G., & Vervaecke, H. (2006). Measuring and testing the steepness of dominance hierarchies. Anim. Behav., 71(3), 585–592.
Abstract: In the analysis of social dominance in groups of animals, linearity has been used by many researchers as the main structural characteristic of a dominance hierarchy. In this paper we propose, alongside linearity, a quantitative measure for another property of a dominance hierarchy, namely its steepness. Steepness of a hierarchy is defined here as the absolute slope of the straight line fitted to the normalized David's scores (calculated on the basis of a dyadic dominance index corrected for chance) plotted against the subjects' ranks. This correction for chance is an improvement of an earlier proposal by de Vries (appendix 2 in de Vries, Animal Behaviour, 1998, 55, 827-843). In addition, we present a randomization procedure for determining the statistical significance of a hierarchy's steepness, which can be used to test the observed steepness against the steepness expected under the null hypothesis of random win chances for all pairs of individuals. Whereas linearity depends on the number of established binary dominance relationships and the degree of transitivity in these relationships, steepness measures the degree to which individuals differ from each other in winning dominance encounters. Linearity and steepness are complementary measures to characterize a dominance hierarchy.
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de VRIES, H. A. N. (1998). Finding a dominance order most consistent with a linear hierarchy: a new procedure and review. Anim. Behav., 55(4), 827–843.
Abstract: A procedure for ordering a set of individuals into a linear or near-linear dominance hierarchy is presented. Two criteria are used in a prioritized way in reorganizing the dominance matrix to find an order that is most consistent with a linear hierarchy: first, minimization of the numbers of inconsistencies and, second, minimization of the total strength of the inconsistencies. The linear ordering procedure, which involves an iterative algorithm based on a generalized swapping rule, is feasible for matrices of up to 80 individuals. The procedure can be applied to any dominance matrix, since it does not make any assumptions about the form of the probabilities of winning and losing. The only assumption is the existence of a linear or near-linear hierarchy which can be verified by means of a linearity test. A review of existing ranking methods is presented and these are compared with the proposed method.
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de Waal, F. B. M. (1992). Coalitions as part of reciprocal relations in the Arnhem chimpanzee colony. In A. H. Harcourt, & F. B. M. de Waal (Eds.), Coalitions and Alliances in Humans and Other Animals (pp. 233–257). Oxford: Oxford University Press.
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