Abstract
Tool-using behaviors of animals have been compared with those of early-man and examined the factors which differentiated the human culture from that of animals. Many tool-using behaviors of animals which are mainly found among birds and primates, particularly in chimpanzees, are flexible to environmental change and have local differences. The reason why they are remarkable only among some separated animal taxa are to be examined through their environment, life form, feeding repertoire and technique. Chimpanzees use and make many different kinds of tools, occasionally do more than one kind of tool for a single purpose and are expected to use a tool for making another tool which needs high intelligence and capability. Examination of local differences of tool-using repertoire of chimpanzees and their environment made clear that they maintain techniques through social tradition, which can be called “culture”. However, its elaboration to man-like culture needs further development of the motor function coordinating both hands and communication method by language.
