Cultural transmission in the tool use and communicatory signaling of chimpanzees?

Not all population differences are cultural in origin: For example, naturalistic observations have revealed that one population of wild rats dives into the Po River for mollusks, whereas another population of rats living on that same river does not.

Abstract

One of the most exciting findings to emerge from recent observations of freeranging chimpanzees in equatorial Africa is that different populations behave differently: They eat different foods, use different tools, and communicate in different ways. These differences seem to persist across generations, and their geographical distribution (neighbors often differ more than do populations living a continent apart) makes it unlikely that they are due to genetic factors. Some researchers have therefore taken to speaking of chimpanzee "culture" (e.g., Goodall, 1973, 1986; McGrew, 1983; McGrew & Tutin, 1978; McGrew, Tutin, & Baldwin, 1979; Nishida, 1980; Nishida, Wrangham, Goodall, & Uehara, 1983; Sugiyama, 1985).