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International Journal of Primatology

, Volume 19, Issue 2, pp 207–235 | Cite as

Survey of Grauer's Gorillas (Gorilla gorilla graueri) and Eastern Chimpanzees (Pan troglodytes schweinfurthi) in the Kahuzi-Biega National Park Lowland Sector and Adjacent Forest in Eastern Democratic Republic of Congo

  • Jefferson S. Hall
  • Lee J. T. White
  • Bila-Isia Inogwabini
  • Ilambu Omari
  • Hilary Simons Morland
  • Elizabeth A. Williamson
  • Kristin Saltonstall
  • Peter Walsh
  • Claude Sikubwabo
  • Dumbo Bonny
  • Kaleme Prince Kiswele
  • Amy Vedder
  • Kathy Freeman
Article

Abstract

We describe the distribution and estimate densities of Grauer's gorillas (Gorilla gorilla graueri) and eastern chimpanzees (Pan troglodytes schweinfurthi) in a 12,770-km2area of lowland forest between the Lowa, Luka, Lugulu, and Oku rivers in eastern Democratic Republic of Congo, the site of the largest continuous population of Grauer's gorillas. The survey included a total of 480 km of transects completed within seven sampling zones in the Kahuzi-Biega National Park lowland sector and adjacent Kasese region and approximately 1100 km of footpath and forest reconnaissance. We estimate total populations of 7670 (4180–10,830) weaned gorillas within the Kahuzi-Biega lowland sector and 3350 (1420–5950) individuals in the Kasese survey areas. Within the same area, we estimate a population of 2600 (1620–4500) chimpanzees. Ape nest site densities are significantly higher within the Kahuzi-Biega lowland sector than in the more remote Kasese survey area in spite of a significantly higher encounter rate of human sign within the lowland sector of the park. Comparison of our data with information obtained by Emlen and Schaller during the first rangewide survey of Grauer's gorillas in 1959 suggests that gorilla populations have remained stable in protected areas but declined in adjacent forest. These findings underscore the key role played by national parks in protecting biological resources in spite of the recent political and economic turmoil in the region. We also show that forest reconnaissance is a reliable and cost-effective method to assess gorilla densities in remote forested areas.

Grauer's gorilla chimpanzee survey conservation Democratic Republic of Congo 

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REFERENCES

  1. Aveling, C., and Aveling, R. (1987). Report from the Zaire gorilla conservation project. Primate Conserv. 8: 162-164.Google Scholar
  2. Aveling, C., and Harcourt, A. H. (1984). A census of the Virunga gorillas. Oryx 18: 8-13.Google Scholar
  3. Barnes, R. F. W., and Barnes, K. L. (1992). Estimating decay rates of elephant dung piles in forest. Afr. J. Ecol. 30: 316-321.Google Scholar
  4. Barnes, R. F. W., and Jensen, K. L. (1987). How to count elephants in forests. IUCN Afr. Elephant Rhino Special. Group Tech. Bull. 1: 1-6.Google Scholar
  5. Basabose, K., Mbake, S., and Yamagiwa, J. (1995). Research and conservation of eastern lowland gorillas in the Kahuzi-Biega National Park, Zaire. Gorilla Conserv. News 9: 11-12.Google Scholar
  6. Buckland, S. T., Anderson, D. R., Burnham, K. P., and Laake, J. L. (1993). Distance Sampling: Estimating Abundance of Biological Populations, Chapman and Hall, London and New York.Google Scholar
  7. Carroll, R. W. (1988). Relative density, range extension, and conservation potential of lowland gorilla (Gorilla gorilla gorilla) in the Dzanga-Sangha region of southwestern Central African Republic. Mammalia 52: 309-323.Google Scholar
  8. East, R. 1996. Antelope Survey Update, Vol. 3, IUCN, Gland.Google Scholar
  9. Emlen, J. T., and Schaller, G. B. (1960). Distribution and status of the mountain gorilla (Gorilla gorilla beringei)—1959. Zoologica 45: 41-52.Google Scholar
  10. Fay, J. M. (1989). Partial completion of a census of the lowland gorilla (Gorilla g. gorilla (Savage and Wayman)) in southwestern Central African Republic. Mammalia 53: 203-215.Google Scholar
  11. Fay, J. M., and Agnagna, M. (1992). Census of gorillas in northern Republic of Congo. Am. J. Primatol. 27: 275-284.Google Scholar
  12. Ghiglieri, M. P. (1984). The Chimpanzees of Kibale Forest: A Field Study of Ecology and Social Structure, Columbia University Press, New York.Google Scholar
  13. Goodall, A. G. (1980). Pilot survey for conservation management of eastern gorillas in Zaire. Final Report, IUCN/WWF Project 1731.Google Scholar
  14. Goodall, A. G., and Groves, C. P. (1977). The conservation of eastern gorillas. In Rainier, P., and Bourne, G. H. (eds.), Primate Conservation, Academic Press, New York, pp. 599-637.Google Scholar
  15. Groom, A. F. (1973). Squeezing out the mountain gorilla. Oryx 12: 207-215.Google Scholar
  16. Hall, J., and Wathaut, W. M. (1992). A Preliminary Survey of the Eastern Lowland Gorilla, Wildlife Conservation Society, New York.Google Scholar
  17. Hall, J. S., Inogwabini, B. I., Williamson, E. A., Omari, I., Sikubwabo, C., and White, L. J. T. (1997). A survey of elephants (Loxodonta africana) in the Kahuzi-Biega National Park lowland sector in eastern Zaire. Afr. J. Ecol. 35: 213-223.Google Scholar
  18. Hall, J., Saltonstall, K., Inogwabini, B. I., and Omari, I. (1998). Distribution, abundance, and conservation status of Grauer's gorilla Gorilla gorilla graueri. Oryx (in press).Google Scholar
  19. Harcourt, A. H., and Groom, A. F. G. (1972). Gorilla census. Oryx 28: 59-70.Google Scholar
  20. Harcourt, A. H., Fossey, D., and Sabater-Pi, J. (1981). Demography of Gorilla gorilla. J. Zool. Lond. 195: 215-233.Google Scholar
  21. Harcourt, A. H., Stewart, K. J., and Inahoro, I. M. (1989). Nigeria's gorillas: A survey and recommendations. Primate Conserv. 10: 73-76.Google Scholar
  22. Harris, D., Fay, J. M., and MacDonald, N. (1987). Report of gorillas from Nigeria. Primate Conserv. 8: 40.Google Scholar
  23. Hart, J. A., and Sikubwabo, C. (1994). Exploration of the Maiko National Park of Zaire 1989–1992: History, Environment and the Distribution and Status of Large Mammals, Wildlife Conservation Society, New York.Google Scholar
  24. Hashimoto, C. (1995). Population census of the chimpanzees in the Kalinzu Forest, Uganda: Comparison between methods with nest counts. Primates 36: 477-488.Google Scholar
  25. Laake, J. L., Buckland, S. T., Anderson, D. R., and Burnham, K. P. (1994). DISTANCE User's Guide V2.1, Colorado Cooperative Fish and Wildlife Research Unit, Colorado State University, Fort Collins.Google Scholar
  26. Marchesi, P., Marchesi, N., Fruth, B., and Boesch, C. (1995). Census and distribution of chimpanzees in Côte D'Ivoire. Primates 36: 591-607.Google Scholar
  27. Merz, G. (1989). Etat actuel des éléphants et des gorilles dans le parc national de Kahuzi-Biega, Zaire. Raport dans le cadre du projet “IZCN—Conservation de la Nature intégrée au Zaire—est” PN 82.2130.1-01.200.Google Scholar
  28. Murnyak, D. F. (1981). Censuing the gorillas in Kahuzi-Biega National Park. Biol. Conserv. 21: 163-176.Google Scholar
  29. Mwanza, N., Maruhashi, T., Yumoto, T., and Yamagiwa, J. (1988). Conservation of eastern lowland gorillas in the Masisi region, Zaire. Primate Conserv. 9: 111-114.Google Scholar
  30. Norton-Griffiths, M. (1978). Counting Animals, African Wildlife Foundation, Nairobi.Google Scholar
  31. Plumptre, A. J., and Reynolds, V. (1996). Censusing chimpanzees in the Budongo Forest, Uganda. Int. J. Primatol. 17: 85-99.Google Scholar
  32. Refisch, J. (1991). Presence des grands mammifères dans le Parc National de Kahuzi-Biega et l'influence humaine sur les populations des animaux. Rapport dans le cadre du Projet IZCN/GTZ—Conservation de la Nature Intégrée, l'Est Zaire.Google Scholar
  33. Remis, M. J. (1993). Nesting behavior of lowland gorillas in the Dzanga-Sangha Reserve, Central African Republic: Implications for population estimates and understanding of group dynamics. Tropics 2: 245-255.Google Scholar
  34. Schaller, G. B. (1963). The Mountain Gorilla, Ecology and Behavior, University of Chicago Press, Chicago.Google Scholar
  35. Stromayer, A. K., and Ekobo, A. (1991). Biological Surveys of Southeastern Cameroon, Wildlife Conservation Society, New York.Google Scholar
  36. Sugiyama, Y., and Soumah, A. G. (1988). Preliminary survey of the distribution and population of chimpanzees in the Republic of Guinea. Primates 29: 569-574.Google Scholar
  37. Tutin, C., and Fernandez, M. (1984). Nationwide census of gorilla (Gorilla g. gorilla) and chimpanzee (Pan t. troglodytes) populations in Gabon. Am. J. Primatol. 6: 313-336.Google Scholar
  38. Tutin, C. E. G., Parnell, R. J., White, L. J. T., and Fernandez, M. (1995). Nest building by lowland gorillas in the Lopé Reserve, Gabon: Environmental influences and implications for censusing. Int. J. Primatol. 16: 55-76.Google Scholar
  39. Vedder, A. L. (1989). Ecology and Conservation of the Mountain Gorilla (Gorilla gorilla berengei), Ph.D. thesis, University of Wisconsin, Madison.Google Scholar
  40. Weber, A. W., and Vedder, A. (1983). Population dynamics of the Virunga gorillas 1959–1978. Biol. Conserv. 26: 341-366.Google Scholar
  41. White, L. J. T. (1994). Biomass of rain forest mammals in the Lopé Reserve, Gabon. J. Trop. Ecol. 63: 499-512.Google Scholar
  42. Williamson, L., and Usongo, L. (1995). I. Survey of primate populations II. Survey of elephants, gorillas, and chimpanzees. Reserve de Faune du Dja, Cameroun. Report to Projet ECOFAC composante Cameroun and Ministère de l'Environment, Cameroun.Google Scholar
  43. Yamagiwa, J. (1983). Diachronic changes in two eastern lowland gorilla groups (Gorilla gorilla graueri) in the Mt. Kahuzi region, Zaire. Primates 24: 174-183.Google Scholar
  44. Yamagiwa, J., Maruhashi, T., Yumoto, T., and Mwanza, N. (1989). A preliminary survey on sympatric populations of Gorilla gorilla graueri and Pan troglodytes schweinfurthi in eastern Zaire. In Interspecies Relationships of Primates in the Tropical and Montane Forests, Grant-in-Aid for Overseas Scientific Research Report, Japan Zaire Cooperative Studies of Primates, pp. 23-40.Google Scholar
  45. Yamagiwa, J., Mwanza, N., Spangenberg, A., Maruhashi, T., Yumoto, T., Fischer, A., Steinhauer-Burkart, B., and Refisch, J. (1992a). Population density and ranging pattern of chimpanzees in Kahuzi-Biega National Park, Zaire: A comparison with a sympatric population of gorillas. Afr. Study Monogr. 13: 217-230.Google Scholar
  46. Yamagiwa, J., Mwanza, N., Yumoto, T., and Maruhashi, T. (1992b). Travel distances and food habits of eastern lowland gorillas. In Itoigawa, N., Sugiyama, Y., Sackett, G. P., and Thompson, R. K. R. (eds.), Topics in Primatology, Vol. 2, University Tokyo Press, Tokyo, pp. 267-282.Google Scholar
  47. Yamagiwa, J., Mwanza, N., Spangenberg, A., Maruhashi, T., Yumoto, T., Fischer, A., and Steinhauer-Burkart, B. (1993). A census of the eastern lowland gorillas Gorilla gorilla graueri in Kahuzi-Biega National Park with reference to mountain gorillas G. g. beringei in the Virunga Region, Zaire. Biol. Conserv. 64: 83-89.Google Scholar

Copyright information

© Plenum Publishing Corporation 1998

Authors and Affiliations

  • Jefferson S. Hall
    • 1
    • 2
  • Lee J. T. White
    • 1
  • Bila-Isia Inogwabini
    • 1
  • Ilambu Omari
    • 2
  • Hilary Simons Morland
    • 1
  • Elizabeth A. Williamson
    • 3
  • Kristin Saltonstall
    • 4
  • Peter Walsh
    • 5
  • Claude Sikubwabo
    • 2
  • Dumbo Bonny
    • 6
  • Kaleme Prince Kiswele
    • 6
  • Amy Vedder
    • 1
  • Kathy Freeman
    • 1
  1. 1.Wildlife Conservation SocietyBronx10460
  2. 2.Marsh Hall, School of Forestry and Environmental StudiesYale UniversityNew Haven
  3. 3.Department of PsychologyUniversity of StirlingStirlingU.K
  4. 4.School of Forestry and Environmental StudiesYale UniversityNew Haven
  5. 5.Department of EntomologyAmerican Museum of Natural HistoryNew York
  6. 6.Laboratoire de Mammalogie, Departement de BiologieCentre de Recherche des Sciences NaturellesLwiroDemocratic Republic of Congo

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