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Fischhoff, I. R., Sundaresan, S. R., Cordingley, J., Larkin, H. M., Sellier, M. - J., & Rubenstein, D. I. (2007). Social relationships and reproductive state influence leadership roles in movements of plains zebra, Equus burchellii. Anim. Behav., 73(5), 825–831.
Abstract: In animal groups, collective movements emerge from individual interactions. Biologists seek to identify how characteristics of actors in these groups, and their relationships, influence the decision-making process. We distinguished two basic factors determining leadership in group choices: identity and state. We hypothesized that identity is more important to leadership in groups with stable relationships, which permit the development of habitual roles. In groups with fluid membership, particular individuals or subgroups are less likely to emerge as consistent leaders. Instead, we predicted that movement initiation in unstable groups depends on individual state at the time of the decision. We characterized how identity and reproductive state influenced leadership patterns in the movements of plains zebra. As in many other mammals, lactation in this species significantly alters water and energy needs. We investigated leadership in tightly knit harems and loosely bonded herds of multiple harems. Harem females tended to have habitual roles in the initiation of harem movement. In herds, however, we found no consistent leaders among harems. At both levels of social organization, lactation was a key determinant of leadership. In harems, lactating females were more likely to initiate movement than nonlactating females. In turn, harems containing lactating females were more likely to lead herd movements. Thus, we conclude that social relationships and reproductive state together shape the interactions that produce group behaviours. One benefit to lactating females of leading herd movements is preferential access to scarce water. Thus, leadership roles in group decisions may have fitness consequences.
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Boogert, N. J., Reader, S. M., & Laland, K. N. (2006). The relation between social rank, neophobia and individual learning in starlings. Anim. Behav., 72(6), 1229–1239.
Abstract: Researchers with diverse interests in topics ranging from the formation of dominance hierarchies and social intelligence to animal personalities have predicted specific, and often conflicting, relations between social rank, neophobia and learning ability. We investigated the relations between these variables in captive groups of wild-caught starlings, Sturnus vulgaris, adopting a multidimensional approach to social rank and neophobia. Both agonistic and competitive rank orders were determined for each group and we tested individuals in the absence of their groupmates for object neophobia, latency to feed in a novel environment and performance on an extractive foraging task. In each starling group, the fastest learners occupied the highest competitive ranks, supporting the hypothesis that cognitive ability is positively correlated with social dominance. Competitive rank orders, however, did not correlate significantly with agonistic rank orders. Situation-specific foraging neophobia was suggested: individuals showed consistency in their latencies to feed near a variety of novel objects, but no significant correlation was found between this measure of object neophobia and latency to feed in a novel environment. Starlings fastest to feed in the novel environment were fastest in solving the foraging task. We discuss the implications of these findings for researchers studying hierarchy formation in animal groups, social intelligence and animal personalities.
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Noirot, E., & Richards, M. P. M. (1966). Maternal behaviour in virgin female golden hamsters: Changes consequent upon initial contact with pups. Anim. Behav., 14(1), 7–10.
Abstract: Summary Initial contact with pups of a certain age causes changes in virgin female hamsters' behaviour with pups of another age. This was shown by comparing the behaviour with 5-day-old pups in groups of naive (control) animals and of animals given one previous contact either with 1, 5 or 9-day-old pups. Maternal responses were more intense in the animals previously presented with 1 or 9-day-old pups than in the control animals. Attacking was increased after initial contact with 1-day-old pups and decreased after initial contact with 9-day-old pups. Animals presented twice with the same pattern did not show marked changes in either of the two activities.
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Chase, I. D. (1985). The sequential analysis of aggressive acts during hierarchy formation: an application of the `jigsaw puzzle' approach. Anim. Behav., 33(1), 86–100.
Abstract: The `jigsaw puzzle' approach is a general method for investigating how interactions among individuals cumulate to form the overall patterns of dominance behaviour in groups. Here, the model is used to discover how aggressive interactions between pairs of individuals modify subsequent interactions with bystanders or third parties. The model indicates that four sequences of successive, aggressive acts are possible in component triads of larger groups: two ensure transitive attack relationships and two can lead to either transitive or intransitive relationships. An application of the model to 14 groups of four hens demonstrates that the two sequences guaranteeing transitivity make up 77% of all sequences. More specifically, hens attacking one group member usually go on to attack a second member, and hens receiving one attack frequently receive a second attack from a bystander. In contrast, an attacked hen rarely `redirects' an attack to a bystander, and a bystander rarely attacks a group member who has just attacked another individual. The application of the jigsaw puzzle approach to aggressive sequences in other species is discussed. Data available for several primate species corroborate the findings in hens and provide support for the method as a general tool for investigating the proximate mechanisms of hierarchy formation.
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Boyd, R., & Silk, J. B. (1983). A method for assigning cardinal dominance ranks. Anim. Behav., 31(1), 45–58.
Abstract: Dominance hierarchies are widely described in nature. Commonly, an individual's ordinal rank is used as a measure of its position in the hierarchy, and, therefore its priority of access to resources. This use of ordinal ranks has several related drawbacks: (1) it is difficult to assess the magnitude or the significance of the difference in degree of dominance between two individuals; (2) it is difficult to evaluate the significance of differences between dominance matrices based on different behaviours or on the same behaviour at different times, and (3) it is difficult to use parametric statistical techniques to relate dominance rank to other quantities of interest. In this paper we describe a method for assigning cardinal dominance indices that does not suffer from these drawbacks. This technique is based on the Bradley-Terry model from the method of paired comparisons. We show how this model can be reinterpreted in terms of dominance interactions. and we describe a simple iterative technique for computing cardinal ranks. We then describe how to evaluate (1) whether the rank differences between individuals are significant, and (2) whether differences in the cardinal hierarchies based on different behaviours or the same behaviour at different times are significant. We then show how to generalize the method to deal with behaviours that sometimes have ambiguous outcomes, or behaviours for which the rank difference between a pair of individuals affects the rate of interaction between them.
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Wolff, P. R., & Powell, A. J. (1984). Urine patterns in mice: An analysis of male/female counter-marking. Anim. Behav., 32(4), 1185–1191.
Abstract: Counter-marking in mice, Mus musculus was investigated by analysing urine deposition on filter paper marked asymmetrically with urine of the opposite sex. Intact males deposited large numbers of urine spots with a marked angular bias towards previously marked quadrants. More spots were deposited on proestrous and ovariectomized donor urine patterns, their distribution being more centrifugal on oestrous urine and more centripetal in quadrants containing a large female urine spot in a central position. In contrast, castrated male mice deposited very few spots with no angular bias. Female urine patterns showed angular bias in response to intact, but not castrated male donor urine, a larger number of spots being produced by oestrous females. Thus the pattern of deposition offers scope for two-way communication of information about reproductive potential.
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Kacelnik, A., & Houston, A. I. (1984). Some effects of energy costs on foraging strategies. Anim. Behav., 32(2), 609–614.
Abstract: We consider the effect of including energy costs on the optimal strategy for animals exploiting a depleting food resource. In the context of central place foraging this leads to the problem of what load size should be brought back to the central place. Two strategies are discussed: (i) maximize gross rate of energy delivery and (ii) maximize net rate of energy delivery. The optimal load size (or optimal patch time) for net maximizers is not always larger than for gross maximizers, as has been claimed. Instead, the difference in optimal load size has the same sign as the difference between metabolic rates of travelling and foraging. We point out that the influence of costs has not always been correctly incorporated in experimental tests of the theory.
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Chapais, B., Girard, M., & Primi, G. (1991). Non-kin alliances, and the stability of matrilineal dominance relations in Japanese macaques. Anim. Behav., 41(3), 481–491.
Abstract: Alliances among kin play a major role in a female's acquisition of her mother's dominance rank in many species of cercopithecines. It is noteworthy, however, that kin rarely form coalitions to challenge females from higher-ranking matrilines, and that matrilineal hierarchies are remarkably stable. One possible reason for the rarity of destabilizing coalitions is that members of high-ranking matrilines form alliances against lower ranking ones. In this paper the patterning of aggressive support among non-kin, and its effect on the stability of rank relations are analysed in a captive group of Japanese macaques, Macaca fuscata, composed of three unrelated matrilines. Analysis of the distribution of non-kin interventions in conflicts between matrilines over a 52-month period revealed a clear pattern of preferential support between the two dominant matrilines against the third-ranking one. This pattern was confirmed experimentally. Any member of the two dominant matrilines was unable, individually, to maintain its rank above the third-ranking matriline, but was able to do so in the presence of the other dominant matriline. Non-kin alliances appear to prevent subordinate females from challenging higher ranking females through revolutionary coalitions (formed among subordinates) or through bridging coalitions (formed among individuals ranking above and below the target). Non-kin support is interpreted in terms of cooperation versus reciprocal altruism.
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Powell, A. J., & Wolff, P. R. (1982). Sex differences in mouse urination patterns. Anim. Behav., 30(4), 1207–1211.
Abstract: When tested in circular open fields male and female mice (Mus musculus) produced strongly centrifugal urination patterns, which showed a clear `edge-dependency' in all the field sizes used. However, striking sex differences in the pattern of deposition were shown in terms of both the number and distribution of the urine spots. Male mice produce large numbers of spots which are regularly dispersed, while females produce relatively fewer spots with a more clumped distribution. It is suggested that a hitherto unsuspected level of intersexual communication may explain these differences.
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Kacelnik, A. (1990). R.C. Bolies and M.D. Beecher, Editors, Evolution and Learning, Lawrence Erlbaum, Hillsdale, New Jersey (1988), p. x. Anim. Behav., 40(3), 602–603.
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