The use of tools, long thought to be uniquely human, has now been observed in other animal taxa including several species of birds, non-primate mammals as well as some non-human primate species. Chimpanzees, one of humankind’s closest living relatives, exceed all other non-human animal species as they have been reported to use an exceptionally large toolkit. However, relatively little is known about the tool-use skills of the other great ape species. While the majority of tools described are inanimate objects, the use of social tools has received relatively little attention. Here we provide the first evidence of naturally occurring spontaneous exploitative behaviour of a conspecific as a social tool for food acquisition in non-human animals. We observed gorillas in captivity utilising a conspecific as a ladder to gain access to unreachable food. We discuss our findings in the light of other studies on social tool use and suggest the need for more nuanced interpretations of gorillas’ cognitive skills.

中文翻译：

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大猩猩 (Gorilla g. gorilla) 对同种动物可供性的了解：种内社交工具用于获取食物

长期以来被认为是人类独有的工具的使用现在已经在其他动物分类群中观察到，包括几种鸟类、非灵长类哺乳动物以及一些非人类灵长类动物。黑猩猩是人类最亲近的近亲之一，超过所有其他非人类动物物种，因为据报道它们使用异常大的工具包。然而，对其他类人猿物种的工具使用技能知之甚少。虽然所描述的大多数工具都是无生命的物体，但社交工具的使用却很少受到关注。在这里，我们提供了同种自然发生的自发剥削行为的第一个证据，作为非人类动物获取食物的社会工具。我们观察到圈养的大猩猩利用同种作为梯子来获取无法获得的食物。