Behavioral Ecology and Sociobiology

, Volume 64, Issue 11, pp 1875–1885

Sequence of quorums during collective decision making in macaques

Authors

    • Unit of Social EcologyUniversité Libre de Bruxelles
    • Université de Strasbourg, IPHC
    • CNRS
    • Department of Ecology and Evolutionary BiologyPrinceton University
    • DEPE, IPHC
  • Jean-Louis Deneubourg
    • Unit of Social EcologyUniversité Libre de Bruxelles
    • CNRS
  • Odile Petit
    • Unit of Social EcologyUniversité Libre de Bruxelles
    • Université de Strasbourg, IPHC
    • CNRS
Original Paper

DOI: 10.1007/s00265-010-0999-8

Cite this article as:
Sueur, C., Deneubourg, J. & Petit, O. Behav Ecol Sociobiol (2010) 64: 1875. doi:10.1007/s00265-010-0999-8

Abstract

Synchronization of activity is one of the major challenges of any society, and to what extent social animals reach a consensus still remains to be established. In the case of group movements, recent studies have underlined the importance of the pre-departure period and suggested that some individuals in a group express their motivation to move by showing a preference for a specific direction. However, how do other group members really choose the time and direction of movement? This study shows that in two semi-free ranging Tonkean macaque (Macaca tonkeana) groups, several individuals propose different directions for movement by displaying unique behavior. The whole group eventually moves in the choice of direction supported by the majority of individuals according to a sequence of three quorum rules. Moreover, when the number of individuals choosing another direction is higher than their own group, individuals that proposed alternative directions eventually renounce and follow the majority. Despite conflict of interests, group members reach a consensus before the actual start of group movement. This demonstrates that processes of this type, which can be considered to be voting processes, are not exclusive to human societies and may be explained by a complex sequence of simple rules.

Keywords

ConsensusVoting processVoteThresholdPrimatesGroup movementSelf-organization

Supplementary material

265_2010_999_MOESM1_ESM.doc (698 kb)
Fig. S1Two instances of the evolution of the number of notifying individuals according to the time for group 1 (a, b) and for group 2 (c, d). The blue line represents the number of notifying individuals in direction 1. The red line represents the number of notifying individuals in direction 2. The black line represents the departure time of the initiator (DOC 698 kb)

Copyright information

© Springer-Verlag 2010