International Journal of Primatology

, Volume 25, Issue 5, pp 1033–1041 | Cite as

Male Masturbation in Free-Ranging Japanese Macaques

  • Ruth Thomsen
  • Joseph Soltis


We studied masturbatory behavior of males over a 14-mo period in free-ranging Japanese macaques (Macaca fuscata yakui) on Yakushima island, Japan. We distinguished 2 types: (1) masturbation only and (2) masturbation with final ejaculation. Both types occurred in all 15 adult troop males. We calculated masturbation only as an index (M/h). It occurred over the whole year; however, it was more frequent during the mating than during the non-mating periods. Masturbation with ejaculation was restricted to the mating period. Male mating success correlated positively with social status. Both rate of masturbation only and masturbatory ejaculations increased as male social status and male mating success declined. Lower-ranking males had higher rates of masturbation only, i.e., they spent more time masturbating than higher-ranking males did. Lower-ranking males also had higher proportions of ejaculates for masturbation, while higher-ranking males used most of their ejaculates for mating.

masturbation Japanese macaques Yakushima 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Altmann, J. (1974). Observational study of behavior: Sampling methods. Behaviour 49: 227–265.PubMedGoogle Scholar
  2. Baker, R. R., and Bellis, M. A. (1993). Human sperm competition: Ejaculate adjustment by males and the function of masturbation. Anim. Behav. 46: 861–885.CrossRefGoogle Scholar
  3. Berard, J. D., Nurnberg, P., Epplen, J. T., and Schmidtke, J. (1994). Alternative reproductive tactics and reproductive success in male rhesus macaques. Behaviour 129: 177–201.Google Scholar
  4. Bercovitch, F. B. (1989). Body size, sperm competition, and determinants of reproductive suc-cess in male savanna baboons. Evolution 43: 1507–1521.Google Scholar
  5. Bielert, C., and van der Walt, L. A. (1982). Male chacma baboon (Papio ursinus)sexual arousal: Mediation by visual cues from female conspecifics. Psychoneuroendocrinology 7: 31–48.CrossRefPubMedGoogle Scholar
  6. Carpenter, C. R. (1942). Sexual behavior of free ranging rhesus monkeys (Macaca mulatta). J. Comp. Psychol. 33: 143–164.Google Scholar
  7. Conover, W. J. (1980). Practical Nonparametric Statistics, Wiley, New-York.Google Scholar
  8. Dunbar, R. I. M. (1984). Reproductive decisions: An economic analysis of gelada Baboon strate-gies, Princeton University Press, Princeton NJ.Google Scholar
  9. Gage, M. J. G. (1994). Associations between body size, mating pattern, testis size and sperm lengths across butterflies. Proc. R. Soc. Lond. B 258: 247–254.Google Scholar
  10. Harcourt, A. H., Harvey, P. H., Larson, S. G., and Short, R. V. (1981). Testis weight, body weight and breeding system in primates. Nature 293: 55–57.PubMedGoogle Scholar
  11. Linnankoski, I., Grönros, M., and Pertovãara, A. (1993). Eye contact as a trigger of male sexual arousal in stump-tailed macaques. Folia primatol. 60: 181–184.PubMedGoogle Scholar
  12. Manson, J. (1996). Male dominance and mount series duration in Cayo Santiago rhesus macaques. Anim. Behav. 51: 1219–1231.CrossRefGoogle Scholar
  13. Maple, T. (1977). Unusual sexual behavior of non-human primates. In Money, J. and Musaph, H. (eds.), Handbook of Sexology, Exerpta Medica, Amsterdam.Google Scholar
  14. Martin, P., and Bateson, P. (2002). Measuring Behaviour, Cambridge University Press, Cambridge, UK.Google Scholar
  15. Maruhashi, T. (1980). Feeding behavior and diet of the Japanese monkey (Macaca fuscata yakui)on Yakushima Island, Japan. Primates 21: 141–160.Google Scholar
  16. Matsubayashi, K., and Enomoto, T. (1983). Longitudinal studies on annual changes in plasma testosterone, body weight and spermatogenesis in adult Japanese monkeys (Macaca fuscata fuscata) under laboratory conditions. Primates 24: 521–529.Google Scholar
  17. Mootnick, A. R., and Baker, E. (1994). Masturbation in captive Hylobates(Gibbons). Zoo. Biol. 13: 345–353.Google Scholar
  18. Nieuwenhuijsen, K., de Neef, K. J., van der Werff, J. J., Bosch, T., and Slob, A. K. (1987). Testosterone, testiz size, seasonality, and behavior in group-living stumptail macaques (Macaca arctoides). Horm. Behav. 21: 153–169.CrossRefPubMedGoogle Scholar
  19. Ohsawa, H., Inoue, M., and Takenaka, O. (1993). Mating strategy and reproductive success of male patas monkeys (Erythrocebus patas). Primates 34: 533–544.Google Scholar
  20. Parker, G. A. (1970). Sperm competition and its evolutionary consequences in the insects. Biol. Rev. 45: 525–567.Google Scholar
  21. Parker, G. A. (1982). Why are there so many tiny sperm? Sperm competition and the mainte-nance of two sexes. J. Theor. Biol. 96: 281–294.PubMedGoogle Scholar
  22. Pound, N., Javed, M. H., Ruberto, C., Anis Shaikh, A., and Del Valle, A. P. (2002). Duration of sexual arousal predicts semen parameters for masturbatory ejaculates. Physiol. Behav. 76: 685–689.CrossRefPubMedGoogle Scholar
  23. Ransom, T. W. (1981). Beach Troop of Gombe, Bucknell University Press, Lewisburg, PA.Google Scholar
  24. Ridley, M. (1999). Book review: Sperm competition and sexual selection. Nature 397: 576–577.CrossRefGoogle Scholar
  25. Soltis, J., Mitsunaga, F., Shimizu, K., Yanagihara, Y., and Nozaki, O. (1999). Female mating strategy in an enclosed group of Japanese macaques. Am. J. Primatol. 47: 263–278.CrossRefPubMedGoogle Scholar
  26. Soltis, J., Thomsen, R., Matsubayashi K., and Takenaka, O. (2000). Infanticide by resident males and female counter-strategies in wild Japanese macaques (Macaca fuscata). Behav. Ecol. Sociobiol. 48: 195–202.CrossRefGoogle Scholar
  27. Soltis, J., Thomsen, R., and Takenaka, O. (2001). The interaction of male and female reproduc-tive strategies and paternity in wild Japanese macaques, Macaca fuscata. Anim. Behav. 62: 485–494.CrossRefGoogle Scholar
  28. Thomsen, R., Soltis, J., and Teltscher, C. (2003). Sperm competition and the function of male masturbation in non-human primates. In Jones, C. B. (ed.), Sexual Selection and Reproductive Competition in Primates: New Perspectives and Directions, ASP-Book Se-ries, Special Topics in Primatology, Vol. 3: pp. 436–453.Google Scholar
  29. Tokuda, K. (1961). A study of the sexual behavior in the Japanese monkey troop. Primates 3: 1–40.Google Scholar

Copyright information

© Springer Science+Business Media, Inc. 2004

Authors and Affiliations

  • Ruth Thomsen
    • 1
  • Joseph Soltis
    • 2
  1. 1.Department of Evolutionary EcologyInstitute for Zoo and Wildlife ResearchBerlinGermany
  2. 2.Animal Programs Administration, Disney's Animal Kingdom, P.O. BoxWildlife Tracking CenterLake Buena VistaUSA

Personalised recommendations