International Journal of Primatology

, Volume 8, Issue 6, pp 635–650 | Cite as

Rank and density correlates of inclusive fitness measures in a natural chacma baboon (Papio ursinus) troop

  • John Bulger
  • William J. Hamilton


Some demographic characteristics of a group of chacma baboons (Papio ursinus)in a natural environment in northern Botswana were monitored for an 8-year interval. The group size ranged from 73 to 43 individuals. After 3 years at a high density, the group size declined over a 2-year interval, then stabilized again at reduced numbers (−41 %) and biomass (−40%) for over 2 years. The reduction in group size and biomass was followed by an increase in fecundity, greater for high-ranking than for low-ranking females. At the larger group size, survival was lower for infants born to low-ranking than to high-ranking females. Infant survival rates by female rank were equal at the lower density. The mean weight of adult females increased as the density decreased, but there was no correlation between female rank and body mass. We conclude that there is a negative relationship of density to individual condition and reproductive success and that there are fitness advantages to high female rank.

Key words

baboon field study fecundity group size infant survival 


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  1. Busse, C. (1982). Leopard and lion predation upon chacma baboons living in the Moremi Wildlife Reserve.Botswana Notes Rec. 12: 15–21.Google Scholar
  2. Busse, C. (1984). Triadic interactions among male and infant chacma baboons. In Taub, D. M. (ed.),Primate Paternalism, Van Nostrand Reinhold, New York, pp. 186–212.Google Scholar
  3. Dunbar, R. I. M. (1980). Determinants and evolutionary consequences of dominance among female gelada baboons.Behav. Ecol. Sociobiol. 7: 253–265.CrossRefGoogle Scholar
  4. Glassman, D. M., Coelho, A. M., Jr., Carey, K. D., and Bramblett, C. A. (1984). Weight growth in savannah baboons: A longitudinal study from birth to adulthood.Growth 48: 425–433.PubMedGoogle Scholar
  5. Hamilton, W. J., III (1982). Baboon sleeping site preferences and relationships to primate grouping patterns.Am. J. Primatol. 3: 41–53.CrossRefGoogle Scholar
  6. Hamilton, W. J., III (1985). Demographic consequences of a food and water shortage to desert chacma baboons,Papio ursinus.Int. J. Primatol. 6: 451–462.CrossRefGoogle Scholar
  7. Hamilton, W. J., III, Buskirk, R. E., and Buskirk, W. H. (1976). Defense of space and resources by chacma (Papio ursinus) baboon troops in an African desert arid swamp.Ecology 57: 1264–1272.CrossRefGoogle Scholar
  8. Mori, A. (1979). Analysis of population changes by measurement of body weight in the Koshima troop of Japanese monkeys.Primates 20: 371–397.CrossRefGoogle Scholar
  9. Van Schaik, C. P. (1983). Why are diurnal primates living in groups?Behaviour 87: 120–144.Google Scholar
  10. Sharman, M., and Dunbar, R. I. M. (1982). Observer bias in selection of study group in baboon field studies.Primates 23: 567–573.CrossRefGoogle Scholar
  11. Smith, K. S. (1986).Dominance and Mating Strategies of Chacma Baboons, Papio ursinus,in the Okavango Delta, Botswana, Ph.D. dissertation, University of California, Davis.Google Scholar
  12. Stacey, P. B. (1986). Group size and foraging efficiency in yellow baboons.Behav. Ecol. Sociobiol. 18: 175–187.CrossRefGoogle Scholar
  13. Strum, S. C., and Western, J. D. (1982). Variations in fecundity with age and environment in olive baboons (Papio anubis).Am. J. Primatol. 3: 61–76.CrossRefGoogle Scholar

Copyright information

© Plenum Publishing Corporation 1987

Authors and Affiliations

  • John Bulger
    • 1
  • William J. Hamilton
    • 1
  1. 1.Division of Environmental StudiesUniversity of CaliforniaDavis, Davis

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