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Gazzola, A., Avanzinelli, E., Mauri, L., Scandura, M., & Apollonio, M. (2002). Temporal changes of howling in south European wolf packs. Ital J Zool, 69.
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Aureli, F., Cords, M., & van Schaik, C. P. (2002). Conflict resolution following aggression in gregarious animals: a predictive framework. Anim. Behav., 64(3), 325–343.
Abstract: Knowledge of how animals manage their conflicts is critical for understanding the dynamics of social systems. During the last two decades research on gregarious animals, especially primates, has focused on the mechanisms of conflict management, mainly on friendly postconflict reunions (also called `reconciliation') in which former opponents exchange affiliative behaviour soon after an aggressive conflict. Our aim in this paper is to present a framework in which the costs and benefits of friendly postconflict reunions, both for each individual opponent and for their mutual relationship, are used to predict the patterning of postconflict resolution mechanisms in other gregarious animals. The framework predicts the occurrence of postconflict reunions in species that live in stable social units, have individualized relationships, and experience postconflict hostility, but especially in those in which intragroup aggression disrupts valuable relationships. The critical issue is whether aggressive conflicts occur between cooperative partners and whether the level of aggression is sufficient to jeopardize the benefits associated with such valuable relationships. We conclude by proposing four research priorities to evaluate the role of friendly reunions in negotiating relationships and the way they are themselves influenced by asymmetries in partner value and biological market effects. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.
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Fawcett, T. W., Skinner, A. M. J., & Goldsmith, A. R. (2002). A test of imitative learning in starlings using a two-action method with an enhanced ghost control. Anim. Behav., 64(4), 547–556.
Abstract: Imitative learning, in which an individual learns to reproduce the behaviour pattern of another, has attracted considerable attention as a potentially powerful form of social learning. Despite extensive research, however, it has proved difficult to demonstrate in nonhuman animals. We investigated the ability of European starlings, Sturnus vulgaris, to imitate the behaviour of a conspecific. Subjects watched a trained conspecific manipulating a plug for access to a food reward, using either a pushing or a pulling action. When later tested with the same apparatus these birds completed the task using the same action they had previously observed. In a second experiment, a separate group of starlings saw the plug move upwards or downwards automatically and a nearby conspecific obtain a food reward. When given access to the task these starlings failed to move the plug in the direction they had seen. Our experiment is an improvement on previous bidirectional control designs and provides strong evidence that starlings are capable of imitation. We advocate further use of this experimental design in attempts to demonstrate imitative learning. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.
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Schuck-Paim, C., & Kacelnik, A. (2002). Rationality in risk-sensitive foraging choices by starlings. Anim. Behav., 64(6), 869–879.
Abstract: Normative models of choice usually predict preferences between alternatives by computing their value according to some criterion, then identifying the alternative with greatest value. An important consequence of this procedure is captured in the economic concept of rationality, defined through a number of principles that are necessary for the existence of an ordinal scale of value upon which organisms base their choices. Violations of these principles, such as some recently reported breaches of transitivity and regularity in birds and honeybees, have strong implications for the understanding of decision mechanisms in humans and nonhumans alike. We investigated rationality in risky choice using European starlings, Sturnus vulgaris. Birds had to choose between two or three food sources, each associated with a different variance in delay to reward. In three experiments, starlings were strongly risk prone, showing regular and consistent preferences in binary and trinary choices. Preferences also satisfied weak and strong stochastic transitivity. Our results extend the generality of previous research in risk-sensitive foraging to situations where more than two alternatives are present and suggest that violations of rationality in risk-sensitive choices may be expressed only under restricted sets of conditions. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.
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Bugnyar, T., & Kotrschal, K. (2002). Observational learning and the raiding of food caches in ravens, Corvus corax: is it `tactical' deception? Anim. Behav., 64(2), 185–195.
Abstract: Group-foraging ravens scatter-hoard when they are competing for food and, to some extent, also raid the caches made by others. We investigated the effects of observational spatial memory on individual caching and raiding tactics. With captive ravens, we found visual observation was essential for locating and raiding the caches of conspecifics. Both captive and free-ranging ravens, food cachers as well as potential cache raiders, responded to each other's presence. Cachers withdrew from conspecifics and most often placed their caches behind structures, obstructing the view of potential observers. Raiders watched inconspicuously and kept at a distance to cachers close to their cache sites. In response to the presence of potential raiders or because of their initial movements towards caches, the cachers frequently interrupted caching, changed cache sites, or recovered their food items. These results suggest that ravens, regardless of whether they act as cachers or raiders, are capable of withholding information about their intentions and, hence, manipulate the other bird's attention either to prevent or to achieve social-learning opportunities. Such interactions may qualify as `tactical' deception and may have created a considerable pressure selecting for social cognition in ravens. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.
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Hauser MD, Pearson H, & Seelig D. (2002). Ontogeny of tool use in cottontop tamarins, Saguinus oedipus: innate recognition of functionally relevant features. Anim. Behav., 64, 299.
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Hauser MD, Santos LR, Spaepen GM, & Pearson HE. (2002). Problem solving, inhibition and domain-specific experience: experiments on cotton-top tamarins, Saguinus oedipus. Anim. Behav., 64, 387.
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Dingemanse, N. J., Both, C., Drent, P. J., van Oers, K., & van Noordwijk, A. J. (2002). Repeatability and heritability of exploratory behaviour in great tits from the wild. Anim. Behav., 64(6), 929–938.
Abstract: We investigated whether individual great tits, Parus major, vary consistently in their exploratory behaviour in a novel environment and measured the repeatability and heritability of this trait. Wild birds were caught in their natural habitat, tested in the laboratory in an open field test on the following morning, then released at the capture site. We measured individual consistency of exploratory behaviour for recaptured individuals (repeatability) and estimated the heritability with parent-offspring regressions and sibling analyses. Measures of exploratory behaviour of individuals at repeated captures were consistent in both sexes and study areas (repeatabilities ranged from 0.27 to 0.48). Exploration scores did not differ between the sexes, and were unrelated to age, condition at fledging or condition during measurement. Heritability estimates were 0.22-0.41 (parent-offspring regressions) and 0.37-0.40 (sibling analyses). We conclude that (1) consistent individual variation in open field behaviour exists in individuals from the wild, and (2) this behavioural variation is heritable. This is one of the first studies showing heritable variation in a behavioural trait in animals from the wild, and poses the question of how this variation is maintained under natural conditions. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.
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Call, J., Aureli, F., & de Waal, F. B. M. (2002). Postconflict third-party affiliation in stumptailed macaques. Anim. Behav., 63(2), 209–216.
Abstract: Stumptailed macaques, Macaca arctoides, are characterized by high levels of postconflict affiliative contacts between opponents. We investigated the occurrence of postconflict affiliative contacts between opponents and third parties that were not involved in the original conflict. We collected 10-min focal observations during postconflict and control periods in which we recorded all aggressive and affiliative behaviours between opponents and third parties. We distinguished three types of third parties depending on the relationship with the focal animal: own kin, opponent's kin and individuals unrelated to both opponents. We analysed the interactions with third parties separately, while distinguishing two classes of affiliative behaviours: (1) allogrooming and contact sitting and (2) sociosexual behaviours (e.g. genital inspection). The macaques showed differences between postconflict and control periods in their affiliative contacts with third parties. Aggressors received more postconflict grooming and contact sitting from their opponents' kin, received more sociosexual behaviour from their own kin and unrelated individuals, and directed more sociosexual behaviour to unrelated individuals. Victims received and directed less postconflict grooming from and towards their own kin. They received more postconflict sociosexual behaviour from all partners except their own kin and directed more sociosexual behaviour to all partners except the opponent's kin. This study establishes the occurrence of multiple postconflict triadic affiliation in stumptailed macaques, and is the first to show that victims receive contacts from third parties in a cercopithecine species, a behaviour previously described only in chimpanzees. It also highlights the importance of analysing the different affiliative behaviours separately in postconflict situations. Otherwise, many of the patterns we report, especially those involving victims, would have been missed.
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Ord, T. J., Peters, R. A., Evans, C. S., & Taylor, A. J. (2002). Digital video playback and visual communication in lizards. Anim. Behav., 63(5), 879–890.
Abstract: Experimental analyses of dynamic visual signals have to overcome the technical obstacle of reproducing complex motor patterns such as those found in courtship and threat displays. Video playback offers a potential solution to this problem, but it has recently been criticized because of sensory differences between humans and nonhuman animals, which suggest that video stimuli might be perceived as deficient relative to live conspecifics. Quantitative comparisons are therefore necessary to determine whether video sequences reliably evoke natural responses. Male Jacky dragons, Amphibolurus muricatus, compete for territories using complex displays delivered in a rapid stereotyped sequence. We evaluated video playback as a technique for studying this visual signal. Digital video sequences depicting a life-sized displaying male were indistinguishable from live male conspecifics in the rate and structure of aggressive displays evoked. Other measures of social behaviour suggested that video stimuli were more effective in this context. Lizards produced significantly more appeasement displays and had higher rates of substrate licking and locomotor activity in response to video playback than to confined male opponents, which failed to produce aggressive displays. Lizards tracked temporal changes in the display rate of video stimuli and were also sensitive to individual differences in morphology and behaviour between video exemplars. These results show that video stimuli are appropriate for the experimental analysis of Jacky dragon aggressive displays. We compare the potential shortcomings of video playback with those of other techniques and conclude that no approach offers a panacea, but that several have complementary characteristics. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.
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