Abstract
Few data exist regarding long-term changes in primate populations in old-growth, tropical forests. In the absence of this information, it is unclear how to assess population trends efficiently and economically. We addressed these problems by conducting line-transect censuses 23.5 years apart at the Ngogo study area in Kibale National Park, Uganda. We conducted additional censuses over short time intervals to determine the degree to which the temporal distribution of censuses affected estimates of primate numbers. Results indicate that two species, blue monkeys and red colobus, may have experienced significant reductions over the past 23.5 years at Ngogo. In contrast, five other species, baboons, black-and-white colobus, chimpanzees, mangabeys, and red-tailed guenons, have not changed in relative abundance. Additional findings indicate that different observers may vary significantly in their estimates of sighting distances of animals during censuses, thus rendering the use of measures of absolute densities problematic. Moreover, censuses conducted over short periods produce biased estimates of primate numbers. These results provide guidelines for the use of line-transect censuses and underscore the importance of protecting large blocks of forests for primate conservation.
Similar content being viewed by others
REFERENCES
Butynski, T. (1990). Comparative ecology of blue monkeys (Cercopithecus mitis) in high-and low-density subpopulations. Ecol. Monogr. 60: 1-26.
Caughley, G. (1980). Analysis of Vertebrate Populations. Wiley, New York.
Chapman, C., Fedigan, L. M., and Fedigan, L. (1988). A comparison of transect methods of estimating population densities of Costa Rican primates. Brenesia 30: 67-80.
Connell, J. (1978). Diversity in tropical rain forests and coral reefs. Science 199: 1302-1310.
Defler, T., and Pintor, D. (1985). Censusing primates by transect in a forest of known primate density. Int. J. Primatol. 6: 243-259.
Freeland, W. (1979). Primate social groups as biological islands. Ecology 60: 719-728.
Ghiglieri, M. (1984). The Chimpanzees of the Kibale Forest, Columbia University Press, New York.
Hutchinson, G. E. (1961). The paradox of plankton. Am. Nat. 95: 137-145.
Lwanga, J. (1987). Group Fission in Blue Monkeys (Cercopithecus mitis stuhlmanni): Effects on the Socioecology in Kibale Forest, Uganda. M.Sc. thesis. Makerere University, Kampala, Uganda.
Mitani, J., and Watts, D. (1999). Demographic influences on the hunting behavior of chimpanzees. Am. J. Phys. Anthrop. 109: 439-454.
National Research Council (1981). Techniques for the Study of Primate Population Ecology. National Academy Press, Washington, D.C.
Newbery, D., Prins, H., and Brown, N. (1998). Dynamics of Tropical Communities, Blackwell Science, Oxford.
Nishida, T. (1968). The social group of wild chimpanzees in the Mahale Mountains. Primates 9: 167-224.
Rowe, N. (1996). The Pictorial Guide to the Living Primates. Pogonias Press, East Hampton, New York.
Seber, G. (1982). The Estimation of Animal Abundance, and Related Parameters. Macmillan, New York.
Siegel, S., and Castellan, N. J. (1988). Nonparametric Statistics for the Behavioral Sciences. McGraw-Hill, New York.
Siex, K., and Struhsaker, T. (1999) Ecology of the Zanzibar red colobus monkey: Demographic variability and habitat stability. Int. J. Primatol. 20: 163-192.
Skorupa, J. (1986). Responses of rainforest primates to selective logging in Kibale Forest, Uganda: A summary report. In Benirschke, K. (ed.), Primates: The Road to Self-Sustaining Populations. Springer-Verlag, New York, pp. 57-70.
Skorupa, J. (1988). The Effects of Selective Timber Harvesting on Rain-Forest Primates in Kibale Forest, Uganda. Ph.D. thesis, University of California, Davis, California.
Struhsaker, T. (1975). The Red Colobus Monkey. University of Chicago Press, Chicago.
Struhsaker, T. (1978). Food habits of five monkey species in the Kibale Forest, Uganda. In Chivers, D., and Herbert, J. (eds.), Recent Advances in Primatology. Academic Press, London, pp. 225-248.
Struhsaker, T. (1997). Ecology of an African Rain Forest. University Press of Florida, Gainesville.
Struhsaker, T. (in press). Variation in adult sex ratios of red colobus monkey social groups: implications for interspecific comparisons. In Kappeler, P. (ed.), Primate Males. Cambridge University Press, Cambridge.
Struhsaker, T., and Leakey, M. (1990). Prey selectivity by crowned hawk-eagles on monkeys in the Kibale Forest, Uganda. Behav. Ecol. Sociobiol. 26: 435-443.
Struhsaker, T., and Leland, L. (1979). Socioecology of five sympatric monkey species in the Kibale Forest, Uganda. Adv. Study Behav. 9: 159-228.
Struhsaker, T., and Leland, L. (1988). Group fission in redtail monkeys (Cercopithecus ascanius) in the Kibale Forest, Uganda. In Gautier-Hion, A., Bourliere, F., Gautier, J. P., and Kingdon, J. (eds.), A Primate Radiation: Evolutionary Biology of the Guenons. Cambridge University Press, Cambridge, pp. 364-388.
Whitesides, G., Oates, J., Green, S., and Kluberdanz, R. (1988). Estimating primate densities from transects in a West African rain forest: A comparison of techniques. J. Anim. Ecol. 57: 345-367.
Rights and permissions
About this article
Cite this article
Mitani, J.C., Struhsaker, T.T. & Lwanga, J.S. Primate Community Dynamics in Old Growth Forest over 23.5 Years at Ngogo, Kibale National Park, Uganda: Implications for Conservation and Census Methods. International Journal of Primatology 21, 269–286 (2000). https://doi.org/10.1023/A:1005477504728
Issue Date:
DOI: https://doi.org/10.1023/A:1005477504728