Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China and Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Nay Pyi Taw, Myanmar.
University of Chinese Academy of Sciences, Beijing, China.
PLoS Biol. 2021 Sep 28;19(9):e3001391. doi: 10.1371/journal.pbio.3001391. eCollection 2021 Sep.
Cooperation is ubiquitous in the animal kingdom as it aims to maximize benefits through joint action. Selection, however, may also favor competitive behaviors that could violate cooperation. How animals mitigate competition is hotly debated, with particular interest in primates and little attention paid thus far to nonprimates. Using a loose-string pulling apparatus, we explored cooperative and competitive behavior, as well as mitigation of the latter, in semi-wild Asian elephants (Elephas maximus). Our results showed that elephants first maintained a very high cooperation rate (average = 80.8% across 45 sessions). Elephants applied "block," "fight back," "leave," "move side," and "submission" as mitigation strategies and adjusted these strategies according to their affiliation and rank difference with competition initiators. They usually applied a "fight back" mitigation strategy as a sanction when competition initiators were low ranking or when they had a close affiliation, but were submissive if the initiators were high ranking or when they were not closely affiliated. However, when the food reward was limited, the costly competitive behaviors ("monopoly" and "fight") increased significantly, leading to a rapid breakdown in cooperation. The instability of elephant cooperation as a result of benefit reduction mirrors that of human society, suggesting that similar fundamental principles may underlie the evolution of cooperation across species.
合作在动物王国中无处不在，因为它旨在通过联合行动来最大化利益。然而，选择也可能有利于可能违反合作的竞争行为。动物如何减轻竞争备受争议，人们对灵长类动物特别感兴趣，而对非灵长类动物关注甚少。我们使用松散的绳索拉动装置，探索了半野生亚洲象（Elephas maximus）的合作和竞争行为，以及对后者的缓解。我们的结果表明，大象首先保持了非常高的合作率（45 次会议的平均合作率为 80.8%）。大象应用了“阻止”、“反击”、“离开”、“移到一边”和“屈服”作为缓解策略，并根据与竞争发起者的关系和等级差异来调整这些策略。当竞争发起者排名较低或关系密切时，它们通常会应用“反击”缓解策略作为制裁，但如果发起者排名较高或关系不密切，则会屈服。然而，当食物奖励有限时，代价高昂的竞争行为（“垄断”和“争斗”）显著增加，导致合作迅速破裂。由于利益减少导致大象合作的不稳定与人类社会相似，这表明合作在物种间的演变可能存在类似的基本原理。
