, Volume 20, Issue 2, pp 161–183 | Cite as

Grouping of the pygmy chimpanzees

  • Suehisa Kuroda


The group formation inPan paniscus is flexible as inP. troglodytes. A group consisted of 16.9 chimps on the average, and a large groups of more than 30 chimps were often observed. The most frequent groups are of the mixed group type, which occupied 80% of the observed cases. The group size varies in accordance with the seasonal changes of the abundance and distribution of food resources, but in general it is larger than that ofP. troglodytes. The socionomic sex ratio does not seem to be highly correlated with the group size, and was around 76 on the average. And neither the proportion of females with infants in a group nor that of estrous females seems to be correlated with the group size. Therefore, the group composition appears to be rather uniform. This uniformity may be attributable toP. paniscus's concentrative nature and high male/female affinity. In comparison with the other African anthropoid apes,P. paniscus shows less sexual differentiation in its social structure.


Social Structure Group Size Seasonal Change Food Resource Group Formation 
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  1. Coolidge, H. J., 1933.Pan paniscus, pygmy chimpanzee from south of the Congo River.Am. J. Phys. Anthrop., 18: 1–59.CrossRefGoogle Scholar
  2. Harcourt, A. H., K. S. Stewart, &D. Fossey, 1976. Male emigration and female transfer in wild gorilla.Nature, 263: 226–227.CrossRefGoogle Scholar
  3. Itani, J., 1972.Social Structure of Primates. Kyoritsu-shuppan, Tokyo. (in Japanese)Google Scholar
  4. ————, 1977. Evolution of primate social structure.J. Hum. Evol., 6: 235–243.Google Scholar
  5. Izawa, K., 1970. Unit groups of chimpanzees and their nomadism in the savanna woodland.Primates, 11: 1–46.CrossRefGoogle Scholar
  6. Kano, T., 1974. The pygmy chimpanzee.Shizen, 7: 28–37. (in Japanese)Google Scholar
  7. ----, in press a. An ecological and sociological study of the pygmy chimpanzee (Pan paniscus) on the right bank of the Njali River. In:The Pygmy Chimpanzee.T. Kano (ed.), NHK, Tokyo. (in Japanese)Google Scholar
  8. ----, in press b. Social interaction among pygmy chimpanzees. In:The Pygmy Chimpanzee.T. Kano (ed.), NHK, Tokyo. (in Japanese)Google Scholar
  9. Kuroda, S., 1977. Pygmy chimpanzees in Wamba.Monkey, 21(6): 6–15. (in Japanese)Google Scholar
  10. ----, in press a. Social behavior of pygmy chimpanzees in Wamba. In:The Pygmy Chimpanzee,T. Kano (ed.), NHK, Tokyo. (in Japanese)Google Scholar
  11. ----, in press b. Natural life of pygmy chimpanzees in Wamba. In:The Pygmy Chimpanzee,T. Kano (ed.), NHK, Tokyo. (in Japanese)Google Scholar
  12. Lawick-Goodall, J. van, 1968. The behaviour of free-living chimpanzees in the Gombe Stream Reserve.Anim. Behav. Monogr., 1(3): 161–311.Google Scholar
  13. Nishida, T., 1968. The social group of wild chimpanzees in the Mahali Mountains.Primates, 9: 167–224.CrossRefGoogle Scholar
  14. ————, 1972. Preliminary information of the pygmy chimpanzees (Pan paniscus) of the Congo Basin.Primates, 13: 415–425.Google Scholar
  15. ————, 1977a. Chimpanzees in the Mahali Mountains (I): Their natural life and structure of the unit group. In:Chimpanzee-ki,J. Itani (ed.), Kôdansha, Tokyo, pp. 543–638. (in Japanese)Google Scholar
  16. ————, 1977b. Social structure of chimpanzees. In:Jinruigaku-Kôza (Anthropology), Vol. 2 (Primates),J. Itani (ed.), Yûzankaku, Tokyo, pp. 277–314. (in Japanese)Google Scholar
  17. Reynolds, V. &F. Reynolds, 1965. Chimpanzees of the Budongo Forest. In:Primate Behavior: Field Studies of Monkeys and Apes,I. DeVore (ed.), Holt, Rinehart & Winston, New York, pp. 368–424.Google Scholar
  18. Savage, S., 1976. Pygmy chimpanzees: Update.Yerkes Newslet., 13(2): 25–26.Google Scholar
  19. Schaller, G. B., 1963.The Mountain Gorilla: Ecology and Behavior. Univ. of Chicago Press, Chicago & London.Google Scholar
  20. Sugiyama, Y., 1968. Social organization of chimpanzees in the Budongo Forest, Uganda.Primates, 9: 225–258.CrossRefGoogle Scholar
  21. Suzuki, A., 1969. An ecological study of chimpanzees in a savanna woodland.Primates, 10: 103–148.CrossRefGoogle Scholar
  22. ————, 1976. Diversity of primate societies. In:A Special Number of Saiensuon Animal Sociology—Hominization.Hominization-Kenkyukai (ed.), The Nihon Keizai, Tokyo, pp. 22–35. (in Japanese)Google Scholar
  23. ————, 1977. Primate ecology. In:Jinruigaku-kôza (Anthropology), Vol. 2 (Primates),J. Itani (ed.), Yûzankaku, Tokyo, pp. 147–194. (in Japanese)Google Scholar
  24. Uehara, S., 1976. Pygmy chimpanzees in Nkele.Monkey, 20(4): 6–11. (in Japanese)Google Scholar

Copyright information

© Japan Monkey Centre 1979

Authors and Affiliations

  • Suehisa Kuroda
    • 1
  1. 1.Laboratory of Physical Anthropology, Faculty of ScienceKyoto UniversityKyotoJapan

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