Chappell Jackie, Kacelnik Alex
Department of Zoology, South Parks Road, OX1 3PS, Oxford, UK.
Anim Cogn. 2004 Apr;7(2):121-7. doi: 10.1007/s10071-003-0202-y. Epub 2003 Nov 29.
One important element of complex and flexible tool use, particularly where tool manufacture is involved, is the ability to select or manufacture appropriate tools anticipating the needs of any given task-an ability that has been rarely tested in non-primates. We examine aspects of this ability in New Caledonian crows-a species known to be extraordinary tool users and manufacturers. In a 2002 study, Chappell and Kacelnik showed that these crows were able to select a tool of the appropriate length for a task among a set of different lengths, and in 2002, Weir, Chappell and Kacelnik showed that New Caledonian crows were able to shape unfamiliar materials to create a usable tool for a specific task. Here we examine their handling of tool diameter. In experiment 1, we show that when facing three loose sticks that were usable as tools, they preferred the thinnest one. When the three sticks were presented so that one was loose and the other two in a bundle, they only disassembled the bundle when their preferred tool was tied. In experiment 2, we show that they manufacture, and modify during use, a tool of a suitable diameter from a tree branch, according to the diameter of the hole through which the tool will have to be inserted. These results add to the developing picture of New Caledonian crows as sophisticated tool users and manufacturers, having an advanced level of folk physics.
复杂且灵活的工具使用，尤其是涉及工具制造时，一个重要因素是能够根据任何给定任务的需求选择或制造合适的工具——这种能力在非灵长类动物中很少得到测试。我们研究了新喀里多尼亚乌鸦这种能力的各个方面，这是一种以非凡的工具使用者和制造者而闻名的物种。在2002年的一项研究中，查佩尔和卡塞尼克表明，这些乌鸦能够从一组不同长度的工具中选择适合某项任务的长度的工具，并且在2002年，韦尔、查佩尔和卡塞尼克表明，新喀里多尼亚乌鸦能够将不熟悉的材料加工成用于特定任务的可用工具。在这里，我们研究它们对工具直径的处理。在实验1中，我们表明，当面对三根可用作工具的松散树枝时，它们更喜欢最细的那根。当三根树枝呈现为一根松散而另外两根捆在一起时，只有当它们喜欢的工具被系住时，它们才会拆开捆。在实验2中，我们表明，它们会根据工具必须插入的孔的直径，从树枝制造并在使用过程中修改出合适直径的工具。这些结果进一步描绘了新喀里多尼亚乌鸦作为复杂的工具使用者和制造者的形象，它们具有较高水平的朴素物理学知识。
