抄録
Primate societies can be described by networks constructed from many different types of dyadic interactions or relationships, which combined produce the complex dynamics we observe. Of particular interest is the relationship between status signaling and aggression networks, as formalized dominance relationships established via status signals are a strategy to mitigate conflict in groups, guiding prioritization of access to resources thereby reducing deleterious aggression. In Rhesus macaques, Silent Bared Teeth Displays given in peaceful contexts (pSBT) are consistently unidirectional signals given from subordinate to dominant that are thought to represent formalized long-term dominance relationships. We compare the use of these signals to dominance probability as calculated from outcomes of aggressive interactions by a Beta Random Field Percolation and Conductance method to test the prediction that dyads connected via both direct and indirect pathways in a pSBT network have greater dominance certainty. We collected data on all occurrences of dominance interactions (aggression, submission, displacements, and SBT) in seven groups of captive rhesus macaques, each containing between 80-150 individuals, at the California National Primate Research Center between June 2008 and December 2009. All pSBT networks showed perfect transitivity, and multilevel generalized linear regression models revealed that dyads with any pSBT path (direct or indirect) had significantly more certain dominance relationships than dyads with no signaling pathway. Compared to dyads that did not have any SBT signal pathway, dyads with a 1-step path (p< 0.01), a 1-step path plus a longer signaling pathway (p< 0.01), a 2-step path (p< 0.01), a 2-step path plus a longer pathway, and a 3-step path (p<0.05) all had higher dominance certainty. Further, dyads with multiple pathways between them showed either the same level of dominance certainty or greater dominance certainty than dyads with only a single path. This demonstrates that, in addition to their value as alternative mechanisms of direct interaction for indicating subordination, the redundant combination of having both direct and indirect signaling pathways may also act to increase the robustness of dominance relationships. These results highlight the connection between two levels of rhesus macaque society - that pathways in a pSBT network exist between individuals that have greater directional consistency in aggression. We argue that pSBT networks are critical for understanding dominance relationships and the maintenance of stability in these complex monkey systems.
