Sakamaki Tetsuya
Primate Research Institute, Kyoto University, 41 Kanrin, Inuyama, Aichi, 484-8506, Japan,
Primates. 2013 Oct;54(4):349-59. doi: 10.1007/s10329-013-0354-6. Epub 2013 Apr 27.
Chimpanzees (Pan troglodytes) groom in gatherings in which many individuals may be connected via multiple chains of grooming and they often exchange partners with each other. They sometimes groom another while receiving grooming; that is, one animal can play two roles (i.e., groomer and groomee) simultaneously. Although this feature of chimpanzees is notable from the viewpoint of the evolution of human sociality, information on our other closest living relative, the bonobo (Pan paniscus), is still lacking. In this study, I describe grooming interactions of bonobos at Wamba in the Luo Scientific Reserve, Democratic Republic of the Congo (DR Congo), with a particular focus on the formation of grooming gatherings. Like chimpanzees, the bonobos also performed mutual grooming (two individuals grooming each other simultaneously) and polyadic grooming (three or more individuals). However, unlike chimpanzees, these sessions lasted for only a short time. Bonobos rarely groomed another while receiving grooming. Because social grooming occurred not only in trees but also in open spaces, including treefall gaps, the conditions did not necessarily limit the opportunity to make multiple chains of grooming. However, bonobos also engaged in social grooming in different ways from chimpanzees; That is, many individuals were involved simultaneously at a site, in which they separated for dyadic grooming. Some cases clearly showed that bonobos preferred a third party not to join while grooming in a dyad, suggesting that bonobos have a preference for grooming in dyads and that immature individuals formed the preference that was shared among adults while growing up. Most members of the study group ranged together during the majority of the study period. Although bonobos show a fission-fusion grouping pattern, when group members frequently encounter one another on a daily basis, they may not be motivated to form multiple grooming chains at this site, as do chimpanzees.
黑猩猩（Pan troglodytes）在群体中进行梳理毛发行为，在这些群体中，许多个体可能通过多条梳理毛发的链条联系在一起，并且它们经常相互交换伙伴。它们有时在接受梳理毛发时还会为其他个体梳理；也就是说，一只动物可以同时扮演两个角色（即梳理者和被梳理者）。尽管从人类社会性进化的角度来看，黑猩猩的这一特征很显著，但关于我们另一个现存的近亲倭黑猩猩（Pan paniscus）的相关信息仍然匮乏。在本研究中，我描述了刚果民主共和国（DR刚果）洛科学保护区万巴的倭黑猩猩的梳理毛发互动情况，特别关注梳理毛发群体的形成。与黑猩猩一样，倭黑猩猩也会进行相互梳理（两个个体同时相互梳理）和多元梳理（三个或更多个体）。然而，与黑猩猩不同的是，这些活动持续时间很短。倭黑猩猩很少在接受梳理时为其他个体梳理。由于社交性梳理不仅发生在树上，也发生在开阔空间，包括树木倒伏形成的缺口处，所以环境条件不一定会限制形成多条梳理毛发链条的机会。然而，倭黑猩猩进行社交性梳理的方式也与黑猩猩不同；也就是说，可以有许多个体同时在一个地点参与，在那里它们会分开进行二元梳理。一些案例清楚地表明倭黑猩猩在二元梳理时更倾向于不让第三方加入，这表明倭黑猩猩更喜欢二元梳理，并且未成熟个体在成长过程中形成了这种为成年个体所共有的偏好。在研究期间的大部分时间里，研究群体的大多数成员都一起活动。尽管倭黑猩猩表现出裂变 - 融合的群体模式，但当群体成员每天频繁相遇时，它们可能不像黑猩猩那样有动力在这个地点形成多条梳理毛发的链条。
