Panthropology of the Fourth Chimpanzee: A Contribution to Cultural Primatology

Abstract

A trademark of Homo sapiens is the enormous variation in behavioural patterns across populations. Insight into the development of human cultures can be aided by studies of Pan communities across Africa, which display unique combinations of social behaviour and elementary technology. Only cross-population comparisons can reveal whether this diversity reflects differential genetics, environmental constraints, or arbitrary cultural patterns. However, the recently recognised and most endangered subspecies Pan troglodytes vellerosus remains completely unstudied in this respect. We report on the Nigerian chimpanzees at Gashaka. At this site, diet composition is highly varied and the apes have to cope with high concentrations of anti-feedant defenses of plants against consumption. It is not surprising therefore, that Gashaka chimpanzees use a varied tool-kit for extractive foraging. For example, they harvest insects throughout the year, employing digging sticks and probes to obtain honey from nests of stingless bees and honey bees, dipping wands to prey on army ants and fishing rods to eat arboreal ants. Tools appeared to be custom-made with a considerable degree of standardisation and preferential use of distal ends. Many of these expressions of subsistence technology seem to be environmentally constrained. Most notably, the absence of termite eating could reflect a low abundance of mounds. Other traits may represent arbitrary cultural variation. For example, two types of hard-shelled nuts found in the habitat are not opened with tools, unlike what is observed elsewhere in West Africa. The prevalence of elementary technology may indicate that the material culture of Gashaka chimpanzees is most closely related to core cultural tendencies of Central African populations of these apes.