Abstract
In order to characterize the social unit in chimpanzees, about which several conflicting views have been proposed, the proximity matrix among 55 recognized chimpanzees and the range covered by each of them are examined, on the basis of data obtained at the Mahale Mountains during 12 months in 1978–1979. It is shown once again that chimpanzees have a bisexual social unit (unit-group). Two such unit-groups were detected in the study area. All animals belonged to one of the two unit-groups except a few cycling females (and a juvenile male accompanied by his cycling mother) which were seen to associate alternately with members of two neighboring unit-groups, covering a whole range of one or even two unit-groups. The problem of such females is discussed in relation to the spatial relationships between the two unit-groups. Reexamining the membership of a unit-group, it is demonstrated that a unit-group was most likely patrilineal. While nulliparous females transferred between unit-groups, parous females tended to remain in a unit-group where they first gave birth to infants and to have several offspring therein. This appeared significant for ensuring recruitment of members of the next generation to a patrilineal unit-group. Although some adult males left their natal unit-group, they never joined the other. Male departure from a unit-group seemed to be forced by the other males and to be the sociological equivalent of going into exile, which is unique in nonhuman primates.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Goodall, J. (van Lawick) (1973). The behaviour of the chimpanzees in their natural habitat.AM. J. Psychiat. 130: 1–12.
Goodall, J. (van Lawick) (1975). The behaviour of the chimpanzee. In Hurth, G., and Eibl-Eibesfeldt, I. (eds.),Hominisation und Verhalten, Gustav Fischer Verlag, Stuttgart, pp. 74–136.
Goodall, J. (1977). Infant killing and cannibalism in free-living chimpanzees.Folia primalol. 28: 258–282.
Goodall, J. (1979). Life and death at Gombe.Natl. Geogr. Mag. 155: 592–621.
Goodall, J., Bandora, A., Bergmann, E., Busse, C., Matama, H., Mpongo, E., Pierce, A., and Riss, D. (1979). Intercommunity interactions in the chimpanzee population of the Gombe National Park. In Hamburg, D. A., and McCown, E. R. (eds.),The Great Apes. Benjamin/Cummings, Menlo Park, Calif., pp. 13–53.
Itani, J. (1977a). Evolution of primate social structure.J. hum. Evol. 6: 235–243.
Itani, J. (1977b).Chimpanzees in the Wild, Heibon-sha, Tokyo (Japanese).
Hani, J. (1980). Social structure of African great apes. In Short, R. V., and Weir, B. J. (eds.),The Great Apes of Africa: J. Reprod. Fert. Suppl. 28: 33–41.
Kano, T. (1982). The social group of pygmy chimpanzees (Pan paniscus) of Wamba.Primates 23: 171–188.
Kawanaka, K. (1981). Infanticide and cannibalism in chimpanzees, with special reference to the newly observed case in the Mahale Mountains.Afr. Stud. Monogr. 1: 69–99.
Kawanaka, K. (1982). A case of inter-unit-group encounter in chimpanzees of the Mahale Mountains.Primates 23: 558–562.
Kawanaka, K., and Nishida, T. (1975). Recent advances in the study of inter-unit-group relationships and social structure of wild chimpanzees of the Mahale Mountains. In Kondo, S., Ehara, A., Kawai, M., and Kawamura, S. (eds.),Proc. Symp. 5th Int. Primatol. Soc, Japan Science Press, Tokyo, pp. 137–186.
Nishida, T. (1968). The social group of wild chimpanzees in the Mahali Mountains.Primates 9: 167–224.
Nishida, T. (1977). Social structure of chimpanzees. In Itani, J. (ed.),Anthropology II: Primates, Yuzankaku, Tokyo, pp. 277–314. (Japanese).
Nishida, T. (1979). The social structure of chimpanzees of the Mahale Mountains. In Hamburg, D. A., and McCown, E. R. (eds.),The Great Apes, Benjamin/Cummings, Menlo Park, Calif., pp. 73–121.
Nishida, T. (1981).The World of Wild Chimpanzees, Chuokoron-sha, Tokyo (Japanese).
Nishida, T., and Kawanaka, K. (1972). Inter-unit-group relationships among wild chimpanzees of the Mahale Mountains.Kyoto Univ. Afr. Stud. 7: 131–169.
Nishida, T., Uehara, S., and Nyundo, R. (1979). Predatory behavior among wild chimpanzees of the Mahale Mountains.Primates 20: 1–20.
Pusey, A. (1979). Intercommunity transfer of chimpanzees in Gombe National Park. In Hamburg, D. A., and McCown, E. R. (eds.),The Great Apes, Benjamin/Cummings, Menlo Park, Calif., pp. 465–479.
Pusey, A. (1980). Inbreeding avoidance in chimpanzees.Anim. Behav. 28: 543–552.
Sugiyama, Y. (1981a).Studies on Behavior and Society of Wild Chimpanzees, Kodan-sha, Tokyo (Japanese).
Sugiyama, Y. (1981b). Observation of the population dynamics and behavior of wild chimpanzees at Bossou, Guinea, in 1979-1980.Primates 22: 435–444.
Sugiyama, Y., and Koman, J. (1979). Social structure and dynamics of wild chimpanzees at Bossou, Guinea.Primates 20: 323–339.
Teleki, G. (1977).Spatial and Temporal Dimensions of Routine Activities Performed by Chimpanzees in Combe National Park, Tanzania: An Ethological Study of Adaptive Strategy, Ph.D. thesis, Pennsylvania State University, University Park.
Uehara, S. (1981). The social unit of wild chimpanzees: A reconsideration based on the diachronic data accumulated at Kasoje in the Mahale Mountains, Tanzania.Africa-Kenkyu 20: 15–32. (Japanese with English summary).
Wrangham, R. W. (1975).Behavioural Ecology of Chimpanzees in Combe National Park, Tanzania, Ph.D. thesis. University of Cambridge, Cambridge.
Wrangham, R. W. (1979). Sex difference in chimpanzee dispersion. In Hamburg, D. A., and McCown, E. R. (eds.),The Great Apes, Benjamin/Cummings, Menlo Park, Calif., pp. 481–489.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Kawanaka, K. Association, ranging, and the social unit in chimpanzees of the Mahale Mountains, Tanzania. Int J Primatol 5, 411–434 (1984). https://doi.org/10.1007/BF02692268
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02692268