Abstract: This study investigated post-conflict (PC) behavior among wild chimpanzees (Pan troglodytes) of the M-group in the Mahale Mountains, Tanzania, and examined what types of behavior characterize the PC situation in this group, and the factors that influence the occurrence of PC affiliation between opponents soon after the end of an aggressive conflict (i.e., reconciliation). We found that the opponents affiliated selectively soon after the end of aggression, suggesting that reconciliation occurred in this group. The mean individual corrected conciliatory tendency (CCT) (Veenema et al. 1994 in Behav Proc 31:29-38) was 14.4%, which is similar to or lower than frequencies observed in studies of captive and wild chimpanzees. The valuable relationship hypothesis predicts that the CCT is higher among individuals who share valuable relationships (e.g., males or affiliative dyads) than among individuals who do not (e.g., females or less-associative dyads). However, the analysis based on data for aggression between unrelated individuals (including one incident between an adult and non-adult) and aggression between unrelated adults, did not uncover this difference. Affiliation by a previously uninvolved individual with the victim (“consolation”) and with the aggressor (“appeasement”) occurred more frequently following aggression than in the control condition. The results are compared with previous studies of captive and wild chimpanzees.

Abstract: This study investigated capuchin monkeys' understanding of their own visual search behavior as a means to gather information. Five monkeys were presented with three tubes that could be visually searched to determine the location of a bait. The bait's visibility was experimentally manipulated, and the monkeys' spontaneous visual searches before tube selection were analyzed. In Experiment 1, three monkeys selected the baited tube significantly above chance; however, the monkeys also searched transparent tubes. In Experiment 2, a bent tube in which food was never visible was introduced. When the bent tube was baited, the monkeys failed to deduce the bait location and responded randomly. They also continued to look into the bent tube despite not gaining any pertinent information from it. The capuchin monkeys' behavior contrasts with the efficient employment of visual search behavior reported in humans, apes and macaques. This difference is consistent with species-related variations in metacognitive abilities, although other explanations are also possible.

Abstract: This study explored whether the tendency of chimpanzees and children to use emulation or imitation to solve a tool-using task was a response to the availability of causal information. Young wild-born chimpanzees from an African sanctuary and 3- to 4-year-old children observed a human demonstrator use a tool to retrieve a reward from a puzzle-box. The demonstration involved both causally relevant and irrelevant actions, and the box was presented in each of two conditions: opaque and clear. In the opaque condition, causal information about the effect of the tool inside the box was not available, and hence it was impossible to differentiate between the relevant and irrelevant parts of the demonstration. However, in the clear condition causal information was available, and subjects could potentially determine which actions were necessary. When chimpanzees were presented with the opaque box, they reproduced both the relevant and irrelevant actions, thus imitating the overall structure of the task. When the box was presented in the clear condition they instead ignored the irrelevant actions in favour of a more efficient, emulative technique. These results suggest that emulation is the favoured strategy of chimpanzees when sufficient causal information is available. However, if such information is not available, chimpanzees are prone to employ a more comprehensive copy of an observed action. In contrast to the chimpanzees, children employed imitation to solve the task in both conditions, at the expense of efficiency. We suggest that the difference in performance of chimpanzees and children may be due to a greater susceptibility of children to cultural conventions, perhaps combined with a differential focus on the results, actions and goals of the demonstrator.

Abstract: This study examines to what extent the concept of dominance can be used to describe the social structure of a group of semi-free-living chimpanzees. 15 behavioural variables, based on agonistic, competitive and affinitive behaviour patterns, have been compared with respect to the interindividual directions in which they occurred. In this analysis use was made of indices that reflect the position an individual occupies in the relationship structure. These indices were calculated per individual for all variables and subjected to factor analysis and cluster analysis. As a result, 13 of the variables could be grouped in three categories which have been labelled: (1) agonistic dominance; (2) bluff dominance, and (3) competitive dominance. Whereas the top positions in the hierarchies based on the first two closely related types of dominance were occupied by the adult males, the hierarchy based on the third type was headed by several adult females.

Abstract: This review highlights two areas of particular interest in the study of social learning in fowl. First, the role of social learning in the development of feeding and foraging behavior in young chicks and older birds is described. The role of the hen as a demonstrator and possible teacher is considered, and the subsequent social influence of brood mates and other companions on food avoidance and food preference learning is discussed. Second, the way in which work on domestic fowl has contributed to an understanding of the importance of directed social learning is examined. The well-characterized hierarchical social organization of small chicken flocks has been used to design studies which demonstrate that the probability of social transmission is strongly influenced by social relationships between birds. The practical implications of understanding the role of social learning in the spread of injurious behaviors in this economically important species are briefly considered.