Culture in Bonobos? Between-species and within-species variation in behavior

Long-term studies on wild chimpanzees (Pan troglodytes) conducted over the past four decades have revealed extensive behavioral variation within and between local populations (McGrew 1983, Nishida et al. 1983, McGrew 1992, Boesch et al. 1994, Wrangham, de Waal, and McGrew 1994, McGrew et al. 1997, Whiten et al. 1999, McGrew et al. 2001). Because chimpanzees live in different habitats across the African continent, they have to cope with a variety of environmental conditions, and therefore the extent of behavioral variation among them is not unexpected. In response to seasonal drought, populations in West and Central Africa have developed special techniques for obtaining water (Hunt and McGrew 2002, Lanjouw 2002). Chimpanzees in dry habitats with low tree density are reported to use nests repeatedly while those living in dense forest habitats rarely use the same nest twice (Fruth and Hohmann 1996). Similarly, the frequency of combining several small trees to construct a single nest varies between populations, probably as a function of forest structure (Fruth and Hohmann 1994). Variation in the extent and quality of insectivory across populations often reflects differences in the availability of prey species (McGrew 1992). Chimpanzees at different sites use different strategies to hunt red colobus monkeys (Colobus badius), and some of this variation can be related to the behavior of the prey species, density of forest cover, and, perhaps, food competition between predator and prey (Boesch 1994, Stanford 1998).