Preface; Foreword: conserving Great Apes Jane Goodall; Part I. Apes Overviewed: 1. Towards an understanding of the orangutan's social system Carel van Schaik and Jan van Hooff; 2. Comparative socio-ecology of gorillas David Watts; 3. Comparative socio-ecology of Pan paniscus Frances J. White; Part II. Social Ecology: 4. Social ecology of Kanyawara chimpanzees Richard Wrangham; 5. Ranging and social structure of lowland gorillas in the Lope Reserve, Gabon Caroline Tutin; 6. Sympatric chimpanzees and gorillas in the Ndoki Forest, Congo Suehisa Kuroda, Tomoaki Nishihara, Shigeru Suzuki and Rufin A. Oko; 7. Dietary and ranin overlap in sympatric gorillas and chimpanzees in Kahuzi-Biega National Park, Zaire Juichi Yamagiwa, Tamaki Maruhashi, Takakazu Yumoto and Ndunda Nwanza; Part III. Social Relations: 8. Social grouping in Tai chimpanzees; 9. Coalition strategies among adult male chimpanzees of the Mahale Mountains, Tanzania Toshisada Nishida and Kazuhiko Hosaka; 10. Male rank order and copulation rate in a unit-group of bonobos at Wamba, Zaire Takayoshi Kano; 11. Comparing copulations of chimpanzees and bonobos Yukio Takahata, Hiroshi Ihobe and Gen'ichi Idani; Part IV. Minds: 12. Conflict as negotiation Frans de Waal; 13. Language perceived: Paniscus branches out E. S. Savage-Rumbaugh, S.Williams, T. Furuichi and T. Kano; 14. Reciprocation in apes C. K. Hemelrijk; 15. Chimpanzee intelligence in nature and captivity Tetsuro Matsuzawa; Part V. Apes Compared: 16. Comparative positional behavior of the African apes Diane Doran; 17. Nest-building behavior in the great apes Barbara Fruth and Gottfried Hohmann; 18. Comparative studies of African ape vocal behavior John Mitani; 19. On which side of the apes? Ethological study of laterality of hand use W. C. McGrew and L. F. Marchant; Part VI. Modelling Ourselves: 20. Savanna chimpanzees, referential models and the Last Common Ancestor Jim Moore; 21. Reconstructions reconsidered: Chimpanzee models and human evolution Adrienne Zihlman; Afterword - A new milestone in great ape research Junichiro Itani; Appendix: Study sites; Index.