, Volume 18, Issue 2, pp 331–357

Intra-troop spacing mechanism of the wild Japanese monkeys of the Koshima troop

  • Akio Mori


The average frequencies of communicative behavior, social behavior, and social encounters (inter-individual proximity within three meters) per hour for a monkey were obtained in their natural habitat by tracing several adult males and females of a Japanese monkey troop living in the Koshima islet. The spatial distribution patterns and the density of troop members within the expanse of the troop at any moment were investigated by tracing several adult femals. Frequency distributions of the monkeys found within five and 10 meters were compared with a Poisson distribution. The frequencies of social encounters and of social interactions of Japanese monkeys were distinctly low, except between mothers and their offspring. The density of monkeys within the expanse of the troop at any moment was very low. Both aggressive behavior and inter-individual proximity (within three meters) were distinctly low when monkeys were foraging for natural food. An avoiding mechanism among troop members plays an important role in maintaining the social structure of these Japanese monkeys. This mechanism works in two ways: each individual does not approach others too closely; the density of monkeys within the expanse of the troop is low at all times.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Crook, J. H. &J. S. Gartlan, 1966. Evolution of primate societies.Nature, London 210: 1200–1203.PubMedGoogle Scholar
  2. Itani, J., 1954.Takasakiyama no Saru (Japanese Monkeys at Takasakiyama). Kobunsha, Tokyo. (in Japanese)Google Scholar
  3. Kawai, M., 1958. On the rank system in a natural group of Japanese monkeys (I), (II).Primates, 1: 111–148. (in Japanese)Google Scholar
  4. Kawamura, S., 1958. The matriarchal social order in the Minoo-B group.Primates, 1: 149–156. (in Japanese)CrossRefGoogle Scholar
  5. Koyama, N., 1967. On dominance rank and kinship of a wild Japanese monkey troop in Arashiyama.Primates, 8: 189–216.CrossRefGoogle Scholar
  6. Kummer, H., 1968.Social Organization of Hamadryas Baboons. A Field Study. Univ. Chicago Press, Chicago.Google Scholar
  7. ————, 1971.Primate Societies: Group Techniques of Ecological Adaptation. Aldine, Chicago.Google Scholar
  8. Marler, P., 1968. Aggregation and dispersal: Two Functions in primate communication. In:Primates: Studies on Adaptation and Variability,P. Jay (ed.), Holt, Rinehart, & Winston, New York, pp. 420–438.Google Scholar
  9. Mori, A., 1975. Signals found in the grooming interactions of wild Japanese monkeys of the Koshima troop.Primates, 16: 107–140.CrossRefGoogle Scholar
  10. Struhsaker, T. T., 1969. Correlates of ecology and social organization among African cercopithecines.Folia primat., 11: 80–118.Google Scholar

Copyright information

© Japan Monkey Centre 1977

Authors and Affiliations

  • Akio Mori
    • 1
  1. 1.Koshima Field Laboratory of the Kyoto University Primate Research InstituteMiyazakiJapan

Personalised recommendations