Preface Andrea B. Taylor and Michele L. Goldsmith; Acknowledgements; Part I. Gorilla Taxonomy and Comparative Morphology: 1. Gorillas: how important, how many, how long? Russell H. Tuttle; 2. A history of gorilla taxonomy Colin P. Groves; 3. Patterns of diversity in gorilla cranial morphology Rebecca M. Stumpf, John D. Polk, John F. Oates, William L. Jungers, Christopher P. Heesy, Colin P. Groves and John G. Fleagle; 4. The hierarchy of intraspecific craniometric variation in gorillas: a population-thinking approach with implications for fossil species recognition studies Gene H. Albrecht, Bruce R. Gelvin and Joseph M. A. Miller; 5. Morphological differentiation of Gorilla subspecies Steven R. Leigh, John H. Relethford, Paul B. Park and Lyle W. Konigsberg; 6. Ontogeny and function of masticatory form in Gorilla: functional, evolutionary and taxonomic implications Andrea B. Taylor; 7. Ontogenetic variation in Gorilla postcranial morphology Sandra E. Inouye; Part II. Molecular Genetics: 8. Gorilla systematics, taxonomy and conservation in the era of genomics Oliver A. Ryder; 9. Mitochondrial and nuclear DNA estimates of divergence between western and eastern gorillas Michael I. Jensen-Seaman, Amos S. Dienard and Kenneth K. Kidd; 10. Genetic studies of western gorillas Stephen L. Clifford, Katherine A. Abernethy, L. J. T. White, Caroline E. G. Tutin, M. W. Bruford and E. Jane Wickings; Part III. Behavioral Ecology: 11. Behavioral ecology Caroline E. Tutin; 12. Gorilla social relationships: a comparative overview David P. Watts; 13. Within-group feeding competition and socioecological factors influencing social organisation of gorillas in the Kahuzi-Biega National Park, Democratic Republic of Congo Juichi Yamagiwa, Kanyunyi Basabose, Kiswele Kaleme and Takakazu Yumoto; 14. Comparative behavioral ecology of a lowland and highland gorilla population: where do Bwindi gorillas fit? Michele L. Goldsmith; 15. Are gorillas vacuum cleaners of the forest floor? The roles of body size, habitat and food preferences on gorilla dietary flexibility and nutrition Melissa J. Remis; Part IV. Gorilla Conservation: 16. Gorilla conservation Alexander H. Harcourt; 17. The current status of gorillas and threats to their existence at the beginning of a new millennium Andrew J. Plumptre, Alastair McNeilage and Jefferson D. Hall; 18. Distribution, taxonomy, genetics, ecology and causal links of gorilla survival: the need to develop practical knowledge for gorilla conservation Esteban E. Sarmiento; 19. The Cross River gorilla: the natural history and status of a neglected and critically endangered subspecies John F. Oates, Kelly L. McFarland, Jacqueline L. Groves, Richard A. Bergl, Joshua M. Linder and Todd R. Disotell; Afterword Michele L. Goldsmith and Andrea B. Taylor.