The challenge of behavioral diversity / Richard W. Wrangham, Frans B.M. de Waal and W. C. McGrew -- Overview--ecology, diversity, and culture / Richard W. Wrangham -- Tools compared : the material of culture / W. C. McGrew -- Party size in chimpanzees and bonobos : a reevaluation of theory based on two similarly forested sites / Colin A. Chapman, Frances J. White, and Richard W. Wrangham -- The significance of terrestrial herbaceous foods for bonobos, chimpanzees, and gorillas / Richard K. Malenky ... [et al.] --Hunting strategies of Gombe and Taï chimpanzees / Christophe Boesch -- Comparative locomotor behavior of chimpanzees and bonobos : species and habitat differences / Diane M. Doran and Kevin D. Hunt -- Comparative analyses of nest-building behavior in bonobos and chimpanzees / Barbara Fruth and Gottfried Hohman -- Diversity of medicinal plant use by chimpanzees in the wild / Michael H. Huffman and Richard W. Wrangham -- Overview--diversity in social relations / W.C. McGrew -- Social role and development of noncopulatory sexual behavior of wild bonbobos / Chie Hashimoto and Takeshi Furuichi.

Grooming relationships in two species of chimpanzees / Yasuyuki Muroyama and Yukimaru Sugiyama -- Reproductive success story : variability among chimpanzees and comparisons with gorillas / Caroline E.G. Tutin -- Ethological studies of chimpanzee vocal behavior / John C. Mitani -- Pacifying interventions at Arnhem Zoo and Gombe / Christopher Boehm -- Social relationships of female chimpanzees : diversity between captive social groups / Kate C. Baker and Barbara B. Smuts -- Chimpanzee's adaptive potential : a comparison of social life under captive and wild conditions / Frans B.M. de Waal -- Overview--culture and cognition / Frans B.M. de Waal -- Understanding chimpanzee understanding / Jan A.R.A.M. van Hooff -- What chimpanzees (might) know about the mind / Daniel J. Povinelli -- The question of chimpanzee culture / Michael Tomasello -- Biobehavioral roots of language : a comparative perspective of chimpanzee, child, and culture / Duane M. Rumbaugh, E. Sue Savage-Rumbaugh, and Rose A. Sevcik -- Individual differences in the cognitive abilities of chimpanzees / Sarah T. Boysen.

Field experiments on use of stone tools in the wild / Tetsuro Matsuzawa -- Afterword--review of recent findings on Mahale chimpanzees : implications and future research directions / Toshisada Nishida -- Postscript--conservation and the future of chimpanzee and bonobo research in Africa / Jane Goodall.