Local behavioral variations and acquisition processes of cultural behavior patterns among wild chimpanzees

我们访问了马哈勒、贡贝（坦桑尼亚）、坎亚瓦拉、恩戈戈、布东戈（乌干达）和博苏（几内亚）六个黑猩猩的野外栖息地，并比较了它们的行为模式。我们还研究了马哈尔文化行为的发展。我们发现了许多地方性的行为差异，比如社交抓痕模式、梳理声音、玩耍、接触水的行为、恐吓表现、求爱表现和自我用药。一种名为“拉叶堆”的游戏模式在许多马哈尔的幼崽和大婴儿身上都有表现，并且至少持续了10多年。然而，这种模式在其他地方并没有被证实是一种传统。马哈勒的幼鱼对溪流的流水表现出不同的游戏模式。面对水面，一些雄性幼鱼和青少年可能会猛烈地纵向摇头，好像在享受自己镜像的运动。一些幼鱼会进行所谓的“吸叶”，也会使用叶中脉来达到类似的目的。这种多样化的水上游戏模式可能是一种时尚或早期的传统，因为它们有可能从一个幼崽传给另一个幼崽，但从录像片段中可以看出，2000年和1994年之间存在一些微妙的行为差异。“泼水”这样的恐吓行为和“剪树叶”、“折灌木”这样的求爱行为很可能是马哈尔黑猩猩的传统。在博苏新记录的“脚后跟踢”、“外阴寄生虫的手掌挤压”和“性皮肤的相互接触”等模式，在马哈尔从未见过。马哈尔大学的一项纵向研究证明，个体是按顺序获得文化模式的：首先是进食行为，然后是梳理行为，然后是使用工具和求爱行为，最后是恐吓行为。他们很可能在断奶期就掌握了几乎所有的传统。社会学习过程被认为是“梳理-握手”形成的原因，在这个过程中，母亲可能会通过“塑造”来教她们的婴儿子女如何握住手。研究表明，一只成年雌鸟在移居到一个新群体20年后，仍能保持原群体的扣扣模式。个体的创新可能在野生黑猩猩中反复发生，但可能很少被固定为一种文化模式。我们能在黑猩猩身上发现许多局部的行为差异，这一事实可能部分地解释为从一个群体传播到另一个群体的缓慢过程。为了研究父亲和后代之间的相似性，我们收集了M组所有个体的粪便等DNA样本，并正在分析y染色体上的基因。少

We visited six field sites of chimpanzees: Mahale, Gombe (Tanzania), Kanyawara, Ngogo, Budongo (Uganda), and Bossou (Guinea) and compared their behavioral patterns among them. We also studied the development of the cultural behavior at Mahale. We discovered many local differences in behavior such as patterns of social scratch, grooming vocalizations, play, water contact behavior, intimidation displays, courtship displays, and self-medications. A play pattern named "Leaf-pile pulling" is shown by many juveniles and old infants of Mahale and has persisted for at least more than 10 years. However, this pattern has not been confirmed to exist as a tradition elsewhere. Juveniles at Mahale show various play patterns in response to running water of streams. Facing with the water surface, several male juveniles and adolescents may shake their head longitudinally violently as if enjoying the movements of their own mirror images. Several juveniles engage in so-called "leaf-sponging" and also use … More the leaf midrib for the similar purpose. Such diversified patterns of water play may be fashions or incipient traditions since they have a likelihood of having been transmitted from a juvenile to another, but there are some subtle behavioral differences between 2000 and 1994 as observed in video clips. It is very likely that intimidation displays such as "Throw splash" and courtship displays such as "Leaf-clipping" and "Shrub-bend" are among the traditions of Mahale chimpanzees. Patterns such as "Heel kick," "Palm squash of ecto-parasites," and "mutual touching of sexual skin" that have been newly recorded at Bossou have never been observed at Mahale. From a longitudinal study at Mahale, it has proved that individuals acquire cultural patterns sequentially: first feeding behavior then grooming behavior, and followed by tool-using and courtship displays, and finally intimidation displays. It is likely that they acquire almost all traditions by the weaning period. Social learning process has been suggested for the formation of "Grooming-hand-clasp," in which mothers may teach their infant offspring how to grasp hands by "molding." An adult female was shown to keep the mode of clasp pattern of her old group even 20 years after her immigration to a new group. Innovation by individuals likely occurs repeatedly among wild chimpanzees, but may rarely be fixed as a cultural pattern. The fact that we can find many local behavioral differences in chimpanzees may be partly explained by the slow process of dissemination from a group to another. In order to investigate the similarity between fathers and offspring, we have collected DNA sample such as feces from all the individuals of M group and are analyzing genes on the Y-chromosome. Less