Non-reciprocal but peaceful fruit sharing in wild bonobos in Wamba

in Behaviour
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Food sharing is considered to be a driving force in the evolution of cooperation in human societies. Previously postulated hypotheses for the mechanism and evolution of food sharing, e.g., reciprocity and sharing-under-pressure, were primarily proposed on the basis of meat sharing in chimpanzees. However, food sharing in bonobos has some remarkably different characteristics. Here I report details pertaining to fruit sharing in wild bonobos in Wamba based on 150 events of junglesop fruit sharing between independent individuals. The bonobos, primarily adult females, shared fruit that could be obtained individually without any cooperation or specialized skills. There was no evidence for reciprocal exchange, and their peaceful sharing seems to contradict the sharing-under-pressure explanation. Subordinate females begged for abundant fruit from dominants; this might indicate that they tested the dominants’ tolerance based on social bonds rather than simply begging for the food itself, suggesting existence of courtesy food sharing in bonobos.

Non-reciprocal but peaceful fruit sharing in wild bonobos in Wamba

in Behaviour



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    (a) Junglesop (Anonidium mannii) fruit, and (b) its remains after a bonobo ate the fruit. Some flesh remained around the seeds (photo by Shinya Yamamoto). This figure is published in colour in the online edition of this journal, which can be accessed via

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    Sharing between adult females. Sl (above) begged for a portion of junglesop (Anonidium mannii) fruit from Nv’s mouth (video-still by Shinya Yamamoto). This figure is published in colour in the online edition of this journal, which can be accessed via

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    Numbers of times eating junglesop fruits individually and receiving them through sharing. Each dot represents an independent individual.

  • View in gallery

    Numbers of times of giving and receiving. Each dot represents an independent individual. No significant correlation was observed between the two. Even for an individual (Hs, indicated by ‘A’ in this figure) who frequently gave and received fruits, the giving and receiving partners did not overlap (see text for details).


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