Abstract # 46:

Scheduled for Saturday, September 13, 2014 07:00 PM-09:00 PM: Session 11 (Decatur B) Poster Presentation


EXPERIMENTAL REMOVAL OF HIGH-RANKING NATAL MALES ALTERS THE STRUCTURE OF SILENT-BARED-TEETH DISPLAY NETWORKS IN CAPTIVE GROUPS OF RHESUS MACAQUES (MACACA MULATTA)

B. A. Beisner1,2 and B. McCowan1,2
1University of California - Davis, Department of Population Health & Reproduction, Davis 95616, USA, 2California National Primate Research Center, University of California, Davis, CA, USA
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     In captivity male rhesus macaques often reside in their natal groups because facilitating natural dispersal behavior is difficult. Previous work by our research team suggests that the presence of high-ranking natal males negatively impacts group stability – high-raking natal males receive agonistic support from female kin and attain sufficiently high rank to challenge alpha males. The patterning of subordination signaling (i.e., silent-bared-teeth displays in peaceful contexts, pSBT) appears to be a good measure of group stability, as frequency and diversity of signals received predicts policing ability and the loss of hierarchical structure in the pSBT network was associated with social collapse in a captive rhesus group. We hypothesized that experimental removal of young, high-ranking natal males would improve group stability by increasing the hierarchical complexity of the SBT network and improving policing success. Aggressive and submissive interactions were recorded in four social groups of rhesus macaques at the California National Primate Research Center for 6 weeks before and after removal of a single natal male. Removal of natal males who occupied a similar network position as the alpha male increased SBT network complexity (i.e. more first- and second-order pathways) and improved overall policing success (B=1.14, p=0.02). We suggest that natal males that have attained a network position that structurally mimics the alpha male indicate a challenge to the alpha position, which may contribute to instability.