Conciliatory Tendency in Captive Brown Capuchin Monkeys (Cebus apella)

J. R. Daniel, A. J. Santos, M. G. Cruz

Unidade de Investigação em Psicologia Cognitiva do Desenvolvimento e Educação- Instituto Superior de Psicologia Aplicada, Portugal


Key Words: Cebus apella . Conflict resolution . Contextual aggression

Conflict resolution has been one of the major topics in primatology in the last decades, nevertheless we still know little about postconflict behaviour in Neotropical species. In this study we investigated conflict resolution behaviour in a captive group of 15 brown capuchins (Cebus apella), using the traditional PC-MC method, in two different contexts: 1) when clumped food was present and 2) in the absence of it. In food condition we identified 72 agonistic events comprising 44.9% of the existent dyads. Tested across all individuals, the proportion of attracted (n=21) and dispersed pairs (n=13) was not statistically different (Wilcoxon signed-ranks: n=11, Z=-1.381, n.s.). In the absence of food we recorded 42 conflicts comprising 34.6% of the existent dyads. As before the proportion of attracted (n=6) and dispersed pairs (n=15) was not statistically different (Wilcoxon signed-ranks: n=11, Z=-1.634, n.s.). Removing from the analyses individuals that contribute with less than three PC-MC pairs did not change the results. Also, in both periods the proportion of affiliative contacts with former opponents was similar in PC and MC observations. The absence of reconciliation in food-related conflicts is in accordance with previous findings. Other authors have pointed out that food-related aggression may be limited to the displacement from the food source without damaging the relationship between the opponents. However, contrarily to Verbeek and de Waal’s results we did not found opponents to be selectively attracted to each other in non-food condition. These differences may be linked to differences in group structure (e.g. assimetry in dominance relationships, number of kin dyads).


M. G. Cruz, A. J. Santos, J. R. Daniel & T. S. Fortes

Unidade de Investigação em Psicologia Cognitiva do Desenvolvimento e da Educação – Instituto Superior de Psicologia Aplicada

Despite high costs of raising an infant, alloparenting is a common practice in the primate order. Individuals other than the mother frequently carry, handle (e.g. inspect, nuzzle, touch) and sometimes nurse the infant during the first months of life. Nevertheless, the function of these interactions is not well understood. Four captive brown capuchin (Cebus apella) infants (all males) were observed during 30 minutes, each week, for their first 5 months of life, from 2004 to 2005. Subjects belonged to a group of 15-16 individuals, housed at the Lagos Zoo, Portugal. As expected, the time during which mothers carried their infants was inversely correlated with infants’ age for all 4 subjects, with alpha female’s infants being carried by others from an earlier age (first month versus third month for the lower ranking females). However, the rate of handling received by infants while being carried by their mother was not influenced by her rank. Approach rates to the mother-infant dyad were neither correlated with the infant’s age nor with the mother’s rank. Harassment episodes were rare, but mother’s frequently interrupted other individuals’ interactions with their infants, either by turning away from, pushing or leaving the handler. Generally, interactions with infants seemed to be more related with characteristics of dyadic relationship between mother and handler, than to mechanisms of dominance rank attraction. Theoretical explanations of alloparenting have been tested in a limited taxonomic group, and as such evaluating the extension of these explanations to a wider number of species is of critical importance.

Keywords: alloparenting, brown capuchin, dominance rank, handling

Affiliative structure and agonistic support in captive brown capuchin monkeys (Cebus apella)

J. R. Daniel, A. J. Santos & M. G. Cruz

Unidade de Investigação em Psicologia Cognitiva do Desenvolvimento e da Educação- Instituto Superior de Psicologia Aplicada

Alliance formation (i.e. one animal intervenes in an ongoing conflict between two parties to support one side) has received considerable attention since it might provide evidence that supporting animals possess relational knowledge of the conflicting parties as well as their relations to other individuals. The purpose of this study was to describe the coalitionary behaviour of a captive group of brown capuchins (Cebus apella), detecting possible effects of spatial proximity and rank. Affiliative subgroups were determined following Strayer & Santos 1996 (Social Development 5, 117-130), while dominance rank was assessed trough David’s score (David 1987, Biometrika 74, 432-436). We recorded 37 occurrences of agonistic support in favour of the aggressor (one supporter n=23, two supporters n=10, three supporters n=2; one excluded), and only one occurrence in favour of the victim (one supporter). Supporters always ranked above victims of conflicts, but only 28% ranked above both aggressor and victim. No significant correlation was found between individual David’s score and support given or received, neither individuals belonging to same subgroups tend to support each other often (nevertheless subgroups existence has been externally validated by social attention data). The fact that most coalitions are directed to the two lowest ranking individuals and involve a restrict number of dyads, seems to suggest the presence of a simple mechanism, opposed to a more complex social-cognitive explanation, underlying alliance formation. Unfortunately, due to lack of records, kinship effect could not be assessed.


Os Primatas do ZooLagos e a sua interacção com os visitantes-Parque Zoológico de Lagos
Conciliatory Tendency in Captive Brown Capuchin Monkeys (Cebus apella)