Abstract: In primate species with unidirectional dominance relationships, rank order restricts the access of nondominant females to clumped resources. However, females might attempt to bypass the rank order by reaching feeding sites before the highest ranking individuals (early arrival tactic) when there are net benefits. We therefore analyzed the order of arrival to the feeding site of the adult members of a captive group of long-tailed macaques. We used 2 experimental conditions that differed in the spatial distribution of a fixed amount of food (large vs. small patch). Though each condition induced contest competition, it was stronger in the small-patch condition. Arrival order does not correlate with dominance rank in either experimental condition. The α-male and α-female reached the feeding site 10-30 s after the beginning of the test. Some females seized on opportunities to reach the feeding site before them, especially in the large-patch condition. They used the early arrival tactic when the risks of aggression were relatively low, which subjects accomplished either by being dominant or by being nondominant but tolerated by the α-male. Social tolerance may provide individuals with an alternative means to obtain resources. In sum, variation in food abundance and distribution may affect the extent to which rank order determines order of arrival to feeding sites. A higher rank may confer priority in the choice of tactics, but not necessarily priority of access to the resources themselves.

Abstract: Conservation of quantity occurs through recognition that changes in the physical arrangement of a set of items do not change the quantity of items in that set. Rhesus monkeys (Macaca mulatta) were presented with a computerized quantity judgment task. Monkeys were rewarded for selecting the greater quantity of items in one of two horizontal arrays of items on the screen. On some trials, after a correct selection, no reward was given but one of the arrays was manipulated. In some cases, this manipulation involved moving items closer together or farther apart to change the physical arrangement of the array without changing the quantity of items in the array. In other cases, additional items were added to the initially smaller array so that it became quantitatively larger. Monkeys then made another selection from the two rows of items. Monkeys were sensitive to these manipulations, changing their selections when the number of items in the rows changed but not when the arrangement only was changed. Therefore, monkeys responded on the basis of the quantity of items, and they were not distracted by non-quantitative manipulations of the sets.

Abstract: Abstract  Researchers have often explained order of progression of group members during joint movement in terms of the influence of ecological pressures but rarely that of social constraints. We studied the order of joining by group members to a movement in semifree-ranging macaques with contrasting social systems: 1 group of Tonkean macaques (Macaca tonkeana) and 1 group of rhesus macaques (M. mulatta). We used network metrics to understand roles and associations among individuals. The way the macaques joined a movement reflected the social differences between the species in terms of dominance and kinship. Old and dominant male rhesus macaques were more often at the front of the movement, contrary to the Tonkean macaques, which exhibited no specific order. Moreover, rhesus macaques preferred to join high-ranking or related individuals, whereas Tonkean macaques based associations during joining mostly on sexual relationships with a subgroup of peripheral males.

Abstract: Aggression can generate anxiety, create uncertainty about its aftermath and jeopardise social relationships. Postconflict interactions serve as conflict management strategies to mitigate these consequences. Whereas postconflict interactions are well characterized in many animals, their functions are still insufficiently investigated. Four functional hypotheses have been proposed: stress reduction, relationship repair, self-protection and benign intent. We aimed to test these hypotheses in females of a tolerant macaque species, the crested macaque, Macaca nigra, under natural conditions, for three postconflict interactions: reconciliation, affiliation and aggression with third parties. Our results provide meaningful contrasts compared with findings in other species. We found no evidence that aggression had consequences for individuals' behavioural indicators of anxiety, although it increased the likelihood of secondary aggression with third parties. There was little evidence for the stress reduction hypothesis as the occurrence of any of the three postconflict interactions investigated had little effect on the measured behavioural indicators of anxiety. Conflict and dyad characteristics also had limited influence on anxiety. The relationship repair function was only partly validated: dyads with stronger bonds or that exchanged more support did not reconcile more often, but dyads with attributes related to the symmetry, stability and predictability (i.e. security) within relationships did. Patterns of initiation and directionality of postconflict interactions in this study population suggest that reconciliation may constitute the signalling of appeasement and benign intent. Furthermore, we found that aggression towards third parties may serve as a source of self-protection and reassertion of the females' social status. The distinctive pattern of postconflict management strategies revealed in wild female crested macaques appears to be related to their typically tolerant social style. These results demonstrate the usefulness of concomitantly studying aggression, postconflict interactions and their functions, to understand conflict management strategies comprehensively, while taking into account the level of social tolerance characterizing the studied society.