Chimpanzees make and use a diverse and rich kit of tools and, with the exception of humans, they are the only living primates to consistently and habitually use and make tools. Each community of chimpanzees has a unique repertoire of tool use behaviours that may differ from that of other communities. Tool use in chimpanzees may serve several purposes including extracting, probing, body cleaning, displaying and pounding. A total of 51% of tools employed by wild chimpanzees are used in a feeding context, while 17% are used in aggressive contexts against conspecifics or other species (mainly leopards, snakes or even humans), 12% are used for communication purposes, 11 % are used to inspect the environment and 9% are used to clean their own bodies.
Cracking is probably the most sophisticated one performed by chimpanzees and has only ever been observed among some populations of the West African subspecies of chimpanzee, although nut-bearing tree species are available at many sites where chimpanzees have been studied elseÂwhere in Central and East Africa.
Tool use in chimpanzees has been shown to play an important role in survival by enabling them to exploit food resources that would be otherwise difficult to access. The other tool use behaviours reported so far include the use of wands to dip for driver ants Dorylus sp. (Chimpanzees may also use a digging stick to dig up the underground nests of these ants) or as probes to fish for termites from their mounds Macrotermes sp.
Studies of chimpanzees in different regions of Africa have revealed that chimpanzee communities exhibit different tool use behaviours and may use different tools for the same purpose at different sites. Nut cracking behaviour is pervasive only in a very small area within the evergreen forest perimeter of West Africa, more precisely west of the N’Zo Sassandra River, which seems to demarcate the eastern limit of its distribution. Chimpanzees clearly demonstrate the ability to fashion tools adapted for the specific purpose of their task and demonstrate variability across sites in their use of raw materials for tool manufacture. Not all of this regional and local variation can be explained by the demands of the physical and biotic environments in which they live. These variations in tool use behaviour have been suggested recently to represent cultural behaviours.