Selection of tool diameter by New Caledonian crows Corvus moneduloides
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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.
KeywordsNew Caledonian crow Tool manufacture Diameter Folk physics
S1: Photograph of one of the oak branches used in the experiment.
S2: This movie shows the first attempt by the female to use a tool in the 4mm hole.
Quicktime MPEG4 (1.74 MB)
S3: In this movie, the female modifies this tool to reduce diameter of the end, and then uses this successfully to remove the food. Both movies form a continuous sequence.
- Anderson JR, Henneman MC (1994) Solutions to a tool-use problem in a pair of Cebus apella. Mammalia 58:351–361Google Scholar
- Aumann T (1990) Use of stones by the Black-breasted Buzzard Hamirostra melanosternon to gain access to egg contents for food. Emu 90:141–144Google Scholar
- Beck BB (1980) Animal tool use: the use and manufacture of tools by animals. Garland, New YorkGoogle Scholar
- Bermejo M, Illera G (1999) Tool-set for termite-fishing and honey extraction by wild chimpanzees in the Lossi Forest, Congo. Primates 40:619–627Google Scholar
- Bowman R (1961) Morphological differentiation and adaptation in the Galapagos finches. Univ Calif Publ Zool 58:1–326Google Scholar
- Boysen ST, Kuhlmeier VA, Halliday P, Halliday YM (1999) Tool use in captive gorillas. In: Parker ST, Mitchell RW (eds) The mentalities of gorillas and orangutans: comparative perspectives. Cambridge University Press, New York, N.Y., pp 179–187Google Scholar
- Fox EA, Sitompul AF, Van Schaik CP (1999) Intelligent tool use in wild Sumatran orangutans. In: Parker ST, Mitchell RW(eds) The mentalities of gorillas and orangutans: comparative perspectives. Cambridge University Press, New York, N.Y., pp 99–116Google Scholar
- Hunt GR (1996) Manufacture and use of hook-tools by New Caledonian crows. Nature 379:249–251Google Scholar
- Hunt GR (2000b) Tool use by the New Caledonian crow Corvus moneduloides to obtain Cerambycidae from dead wood. Emu 100:109–114Google Scholar
- Parker ST, Gibson KR (1977) Object manipulation, tool use and sensorimotor intelligence as feeding adaptations in Cebus monkeys and great apes. J Hum Evol 6:623–641Google Scholar
- Povinelli DJ (2000) Folk physics for apes: a chimpanzee’s theory of how the world works. Oxford University Press, OxfordGoogle Scholar
- Thouless CR, Fanshawe JH, Bertram BCR (1989) Egyptian vultures Neophron percnopterus and Ostrich Struthio camelus eggs—the origins of stone-throwing behavior. Ibis 131:9–15Google Scholar
- Tomasello M, Call J (1997) Primate cognition. Oxford University Press, New YorkGoogle Scholar