Kopp Kathrin S, Liebal Katja
Department of Education and Psychology; Comparative Developmental Psychology, Freie Universität Berlin, Berlin, Germany.
PeerJ. 2018 Jul 31;6:e5303. doi: 10.7717/peerj.5303. eCollection 2018.
Peaceful conflict resolution strategies have been identified as effective mechanisms for minimising the potential costs of group life in many gregarious species, especially in primates. The knowledge of conflict-management in orangutans, though, is still extremely limited. Given their semi-solitary lives in the wild, there seems to be barely a need for orangutans to apply conflict management strategies other than avoidance. However, because of the rapid loss of orangutan habitat due to deforestation, opportunities to prevent conflicts by dispersion are shrinking. Additionally, more and more orangutans are brought into rehabilitation centres where they are bound to live in close contact with conspecifics. This raises the questions of whether and how orangutans are able to cope with conflicts, which are inevitably connected with group life.
Observational zoo-studies provide a valuable method to investigate such potential: in zoos, orangutans usually live in permanent groups and face the challenges of group life every day. Therefore, we observed a group of six socially-housed Sumatran orangutans at the Dortmund Zoo, Germany, both in their spacious outdoor enclosure in the summer and in the less spacious indoor enclosure in the winter. During 157.5 h of observation, we collected data on aggressive interactions, third-party interventions and post-conflict affiliations. We applied the post-conflict/matched-control observation (PC/MC) and the time rule method to investigate the occurrence of reconciliation and post-conflict third-party affiliations.
We recorded a total of 114 aggressive interactions (including conflicts in the context of weaning and of male sexual coercion). As expected, we found an increase of both open conflicts and peaceful conflict resolution under less spacious conditions. In accordance with previous reports, we observed interventions by initially uninvolved individuals. Whereas we found no clear evidence for post-conflict third-party affiliations, we were able to demonstrate the occurrence of reconciliation among orangutans.
Notwithstanding the small sample size and the explorative character of our study, we found evidence that orangutans possess a potential for prosocial conflict resolution. When living in groups and under conditions in which dispersion is no longer an option, orangutans are capable to flexibly apply strategies of conflict resolution to cease open conflicts and to repair the potential social damage of aggressive interactions. These strategies are similar to those of other great apes.
和平解决冲突的策略已被确认为许多群居物种，尤其是灵长类动物，将群体生活潜在成本降至最低的有效机制。然而，对于红毛猩猩冲突管理的了解仍然极为有限。鉴于它们在野外过着半独居生活，除了回避之外，红毛猩猩似乎几乎没有必要运用冲突管理策略。然而，由于森林砍伐导致红毛猩猩栖息地迅速丧失，通过分散来预防冲突的机会正在减少。此外，越来越多的红毛猩猩被送往康复中心，在那里它们必然会与同类密切接触。这就引发了红毛猩猩是否以及如何能够应对与群体生活不可避免相关的冲突的问题。
动物园观察研究为调查此类可能性提供了一种有价值的方法：在动物园里，红毛猩猩通常生活在固定群体中，每天都面临群体生活的挑战。因此，我们观察了德国多特蒙德动物园一群六只群居的苏门答腊红毛猩猩，夏天在宽敞的室外围场，冬天在空间较小的室内围场。在157.5小时的观察期间，我们收集了有关攻击性行为、第三方干预和冲突后关系的数据。我们应用冲突后/匹配对照观察法（PC/MC）和时间规则法来研究和解以及冲突后第三方关系的发生情况。
我们总共记录了114次攻击性行为（包括断奶和雄性性胁迫背景下的冲突）。正如预期的那样，我们发现在空间较小的条件下，公开冲突与和平解决冲突的情况都有所增加。与先前的报告一致，我们观察到最初未参与的个体进行了干预。虽然我们没有找到冲突后第三方关系的明确证据，但我们能够证明红毛猩猩之间存在和解现象。
尽管我们的研究样本量较小且具有探索性质，但我们发现有证据表明红毛猩猩具有亲社会冲突解决的潜力。当生活在群体中且分散不再是一种选择的情况下，红毛猩猩能够灵活运用冲突解决策略来停止公开冲突，并修复攻击性行为可能造成的社会损害。这些策略与其他大型猿类的策略相似。
