Abstract # 4610 Event # 35:

Scheduled for Thursday, June 20, 2013 12:00 PM-12:15 PM: Session 4 (San Geronimo Ballroom C) Oral Presentation


WHAT DO OPPONENTS DO AFTER A FIGHT? ANALYZING THE DETERMINANTS OF RECONCILIATION AND RENEWED AGGRESSION IN WILD CHIMPANZEES (PAN TROGLODYTES), KANYAWARA, KIBALE NATIONAL PARK, UGANDA.

J. A. Hartel and C. B. Stanford
University of Southern California, Department of Biological Sciences, Los Angeles, CA 90089, USA
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Following conflicts, opponents can chose reconciliation, renewed aggression, or avoidance. This study aimed to determine what variables influenced wild chimpanzee opponent post-conflict decisions. I hypothesized that preferred social partner opponents would be more likely to reconcile than neutral partners, and in turn would avoid further aggression. Wild chimpanzee aggression and reconciliation data were collected over a one-year period at Kanyawara. I analyzed post-conflict interactions from 636 aggression observations between 181 adult dyads. Reconciliation occurred 122 times between 56 dyads, and renewed aggression occurred 102 times between 51 dyads. Reconciliation and renewed aggression occurred in the same conflict 8 times. The dyadic corrected conciliatory tendency was 14% and renewed aggression tendency was 12%. Generalized linear mixed models (GLMMs) determined that combining valuable relationship parameters into one composite measure and conflict intensity variables into another composite measure was the most effective means to predict reconciliation and renewed aggression, respectively. Mutual preferred social partners were significantly more likely to reconcile than were neutral partners (GLMM, p=0.0007). If the aggressor was an overall preferred social partner of the victim, this was an even better predictor of reconciliation (GLMM, p=0.0001). Conflict intensity variables, on the other hand, best predicted renewed aggression (GLMM, p<0.0001). While this study provides support for the valuable relationship hypothesis, it also suggests that aggressive decisions made during the conflict are equally important in preventing renewed aggression.