黑猩猩将木棍伸进蚁巢“钓”白蚁，是动物也会使用工具的典型例证。科学家也早就知道，黑猩猩会把细木棍伸进蚁巢，等着白蚁沿着木棍爬上来，美餐一顿。但以往对这一现象的了解十分有限，观察证据不多。
科学家新近对野生黑猩猩所作的一项隐蔽观察，进一步证实了这种现象的存在，并且表明黑猩猩比我们认为的更聪明：针对不同类型的蚁巢，它们会使 用不同的工具。
据美国《科学》杂志网站报道，德国马克斯·普朗克进化人类学研究所等机构的研究人员，在刚果盆地一个偏远地区的白蚁蚁巢附近，安装了隐蔽的摄像机。这个地区生活着数以千计的黑猩猩，它们从未接触过人类。有关观察报告发表在１１月号的《美国博物学家》杂志上。
科学家介绍说，在６个月时间里，摄像机拍到１２１只黑猩猩反复地到６个蚁巢取食。它们使用了人们迄今在野生黑猩猩中观察到的最复杂的工具和技巧，并且会针对不同类型的蚁巢使用不同工具。
黑猩猩觅食的蚁巢一般有两类，一类是隆起在地面上的蚁丘，一类是地下蚁巢。对于蚁丘，黑猩猩会先用一根较短的小木棍伸进去，再换成一根“探针”，方便白蚁爬上来。而对于地下蚁巢，黑猩猩先用一根较长的木棍刺下去找到蚁巢，然后换成“探针”。观察发现，黑猩猩在交替使用这些工具时非常灵巧敏捷。
此外，“发掘”地下蚁巢时，黑猩猩有时会把一只脚踩在木棍上，将木棍往土里推，就像人类使用铲子那样。还有一只雌性黑猩猩将木棍的一端嚼碎，形成刷子模样，以便让更多的白蚁爬上来。
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What's in a Chimp's Toolbox?
Hidden cameras in the Congo rainforest have captured the closest look yet at tool use by chimps in the wild, finding that the wily primates use different types of sticks depending on the termite colony they're trying to pillage.
While scientists know chimps use sticks to "fish" for termites, the knowledge is based only on indirect evidence and fleeting field observations. Now David Morgan of the Wildlife Conservation Society and Crickette Sanz, a postdoc at the Max Planck Institute for Evolutionary Anthropology in Leipzig, have obtained an abundance of direct evidence after planting motion-sensing video cameras near termite mounds and nests in a remote area of the Congo Basin called the Goualougo Triangle, which is home to thousands of chimps that have never had any dealings with humans. Over 6 months they filmed 121 chimps that repeatedly visited six termite nests.
Right tool for the job.
Hidden cameras have revealed that wild chimps select tools that suit the task.
In a report published in the November issue of the American Naturalist, the authors describe what they say are "some of the most complex tool kits and techniques that have been observed in wild chimpanzees." The chimpanzees regularly visit two kinds of termite nests and use two different sets of tools to extract their prey. For mounds, the chimps first punch into the nest with a small, short stick. Then they switch to a "fishing probe" that the termites crawl onto. For underground nests, the chimps use a longer "puncturing stick" to get to the nest and follow up with their probes. The videos show them nimbly switching back and forth between the two tools. They can also be seen placing a foot on the stick to push it into the ground like a shovel. In one video, a female chimp pulls a stick through her teeth, shredding the end to make it like a brush, which picks up more termites.
The study fills in a big gap in our knowledge about chimp tool use, says Harvard primatologist Richard Wrangham. "Until now our view of chimpanzee termite-fishing has been overly biased by data on the fringe populations in East Africa." But those chimps only use their hands to puncture termite nests. Wrangham says some scientists have considered tool-use a special adaptation for drier habitats. But this research, which shows it's widespread in equatorial forests, "heralds a new wave of information about the ecological and cultural significance of termite-fishing."
Related sites
An article and videos of the chimps from National Geographic, which sponsored the research
Max Planck chimp project
Information about chimps from the Jane Goodall Institute
