The knowledge that chimpanzees hunt vertebrates and share meat continues to fuel the imagination and grant proposals of many field researchers who study Pan. Hunting and food sharing have played an important role in constructing models of human origins (Dart 1953; Isaac 1978; Lovejoy 1981; Stanford ' Bunn, 2001). The presence of sharing in Pan helps us to speculate about how the last common ancestor of living apes and humans may have dealt with scarce and contested food resources (Marchant, in press).

It was in 1963 that Jane Goodall published her findings revealing how powerfully meat figures in the lives of chimpanzees. More recently, we have also learned that bonobos are intensely interested in eating vertebrate flesh and share the prey (Ihobe 1992; Hohmann & Fruth 1993). The three chapters in this section provide new insights into both Pan species and enlarge our understanding of species differences and similarities.

Boesch et al. discuss chimpanzee predation on red colobus monkeys (Chapter 16), sharpening our understanding of this predator–prey system, and adding more complexity to how we might model ancestral hominid hunting patterns. The chapter is unusual in providing a three-site comparison (Gombe and Mahale in East Africa, and Ta in West Africa) by the same observer (C. Boesch). Boesch (1994) studied chimpanzee hunting behavior at Gombe and Ta and here extends the analysis, while Uehara and Ihobe provide an update and further analysis of prey availability at Mahale (Uehara et al. 1992). We learn that demographic changes in either predator or prey may have a significant impact on hunting frequency, species targeted, and number of monkeys taken annually.