The Basics of Chimp Technology

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"The chimpanzee uses the objects of his environment as tools to a greater extent than any other living animal with the exception of man himself." ~ Jane Goodall, In the Shadow of Man

It's been nearly 50 years since Jane Goodall made the observations that inspired these words. Today, they are still true—chimpanzees are second only to humans in the variety of tools they use and the innovative ways they employ those tools.

Since Jane Goodall's pioneering work began in the early 1960s, she and other scientists have discovered that chimpanzees not only use tools, they combine them, use them in sequence, and create new tools from various subcomponents.

In the April 30 issue of Science, Cambridge University anthropologist William McGrew summarizes what we currently know about chimpanzee technology. In his article, William McGrew provides several definitions that are useful in understanding what he refers to as "chimpanzee technology". These include:

  • Tool kit - A tool kit is the repertoire of tools that a group of chimpanzees use. Most chimpanzee groups have tool kits that consist of about 20 different tools. Tools in a tool kit are used for various functions such as feeding, sociality, courtship, grooming.
  • Tool set - A tool set is a group of two or more tools that are used in sequence to achieve a goal. An example of a tool set comes from a chimpanzee population in Gabon. These chimps use a tool set that consists of five tools (pounder, perforator, enlarger ,collector, and swab) to obtain honey. Tools in a tool set must be used in the correct sequential order to work. This complexity, the ordered use of several tools, has some primatologists saying this signifies chimps are capable of complex cognitive machinations.
  • Tool composite - A tool composite consists of two or more objects that are used simultaneously to achieve a goal. An example of a tool composite would be a stone hammer that is used to crack nuts against a stone anvil.
  • Compound tools - A compound tool consists of two or more component tools are combined into a single device. An example of a tool composite used by chimpanzees is a leaf sponge. A leaf sponge is made from several fresh leaves that are combined to form an absorbent clump. The clump is used by the chimps to extract water from crevices such as tree holes.

    Of all the living great apes only two groups, bonobos and gorillas, have not developed the habit of using tools. Laboratory studies reveal that these apes are as intelligent as chimpanzees, so there must be some other reason for their disinterest in tools. Orangutans are more similar to chimpanzees in that they have tool kits. But since orangutans spend much of their lives in treetops, they tend to use tools to a lesser extent than their more grounded chimp cousins.

    Scientists still wonder when ancestral chimpanzees began using and making complex tools. The answer to this question has been so far elusive. Although experts can tell the difference between ancient tools and damaged rocks or petrified twigs (the tools show diagnostic patterns of wear and use) there are few clues to identity of the organism that used the tools. Scientists are still searching for diagnostic wear patterns on tools that would enable them to distinguish tools used by ancient chimpanzees from tools used by other great ape ancestors.

    References

    McGrew, W. (2010). Chimpanzee Technology Science, 328 (5978), 579-580 DOI: 10.1126/science.1187921