The role of the dominant male in group coordination by tufted capuchin monkeys (Sapajus nigritus)

SCARRY, C. J.; TUJAGUE, M. P.

Göttingen

Conferencia; X Göttinger Freilandtage Conference; 2015

German Primate Centre

Although consensus decision-making regarding collective movements requires that group members conform to the decision; individuals do not necessarily contribute equally to the decision-making process. Through the use of a natural removal experiment, we examined the decision-making process underlying post-departure coordination of group movements among Argentine tufted capuchin monkeys (Sapajus nigritus), focusing on the role of an undisputed dominant male for achieving a consensus among group members. We conducted all-day follows of two social groups, recording the spatial location of the group?s center of mass at 15-minute intervals. Although dominant males generally occupied a central spatial position and did not lead group progressions, following the death of the dominant male in one group, group movements became more erratic as directed forward movement decreased, and backtracking increased. In contrast, despite multiple changes in the identity and number of adult and subadult males within the second social group, similar interannual differences in the directness of travel were not apparent. Nevertheless, in spite of the increased frequency of short-term changes in the direction of group movement, the absence of the dominant male had no apparent effect on the number of long-distance, goal-directed travel segments per day. These differences in the impact of a stable male dominance hierarchy on group movements depending on the scale of analysis suggest: 1) selective mimitism of travel decisions by dominant males has a pronounced effect on the coordination of short-term group movements and 2) group coordination in landscape-scale space is governed by a separate mechanism.