The 82nd Annual Meeting of the American Association of Physical Anthropologists (2013)

Effect of opponent distance on post-conflict behavior in wild chimpanzees, Kanyawara, Kibale National Park, Uganda


Department of Biological Sciences, University of Southern California

Thursday 1:30-1:45, Ballroom B Add to calendar

Post-conflict behavior has been extensively studied in captive populations, but field data are limited. I argue that wild chimpanzee fission-fusion social structure complicates applications of captive data to naturalistic populations. In particular, distancing strategies following aggression may play a key role in wild post-conflict behavior. I hypothesized that opponent distance affects wild chimpanzees’ post-conflict decisions. Specifically, I predicted that increased distance would decrease reconciliation and vice versa. This research investigated the reconciliation behavior of adult wild chimpanzees at Kanyawara over a one-year period. I analyzed post-conflict interactions from 636 aggressive observations between 181 adult dyads. Reconciliation occurred 122 times between 56 adult dyads. Overall, the Kanyawara chimpanzees had a corrected conciliatory tendency (14%) similar to other wild populations (Mahale-15%, Tai-16%, Budongo-19%), but notably lower than their captive counterparts (ranging 22-48%). Male-male dyads had the highest conciliatory tendency (23%), followed by male-female (14%) and female-female (3%) dyads. Generalized linear mixed models determined opponent distance was the best predictor of reconciliation. Opponents within 10 meters after the conflict were more likely to reconcile than those beyond 10 meters, indicating distancing strategies influence reconciliation. Higher reconciliation rates in captivity may be a byproduct of enforced proximity. However, close proximity following aggression presented a tradeoff at Kanyawara. Data showed that opponents within 10 meters also had a higher risk of renewed aggression, but this risk greatly decreased if/after opponents reconciled. This study demonstrates the importance of space in post-conflict decisions and explains how differences might emerge between wild and captive populations.

This study was funded by the Wenner-Gren Foundation (Grant # 8249), International Primatological Society, and University of Southern California.

comments powered by Disqus