International Journal of Primatology

, Volume 34, Issue 2, pp 281–302 | Cite as

The Distribution, Status, and Conservation Outlook of the Drill (Mandrillus leucophaeus) in Cameroon

  • Bethan J. Morgan
  • Ekwoge E. Abwe
  • Alan F. Dixson
  • Christos Astaras


The populations of many endangered species are becoming increasingly fragmented, and accurate, current information on the status of these subpopulations is essential for the design of effective conservation strategies within a human-dominated landscape. The drill (Mandrillus leucophaeus) is one of the most spectacular and endangered primates in Africa, yet up-to-date information on its distribution, population status, and conservation outlook is lacking. Cameroon has been estimated to encompass 80 % of the species’ range. We examined the distribution, population status, and conservation outlook for the drill throughout its historic range in Cameroon. To do this, we divided the historic range of the drill in Cameroon (46,000 km2) into 52 survey units along natural and manmade boundary features. Based on a series of field surveys in 2002–2009, village interviews, analysis of geospatial data, and bibliographical research, we assigned each survey unit a rank of 0–4 for 15 parameters indicative of current situation for drills, habitat suitability, and conservation outlook. We obtained direct evidence for the presence of drills in 16 of the 52 survey units, with those of Ejagham, Korup, Ebo, and Nta Ali receiving the highest index scores. We warn of local extirpations and increased isolation among drill populations due to loss of dispersal corridors, e.g., Douala Edea survey unit. In some cases drills persist in forest fragments within human-dominated landscapes, e.g., Kupe-Manenguba, but the species’ future is probably dependent on effective wildlife management in a handful of isolated strongholds where probability of long-term protection is higher, particularly in Korup National Park, Takamanda National Park, and the proposed Ebo National Park. Pressure from current and proposed large-scale commercial plantations, oil prospecting, logging, and the continual human population growth in this region means that a concerted conservation effort will be needed to safeguard the remaining drill habitat if the species is to survive in Cameroon.


Africa Cameroon Conservation Drill Mandrillus leucophaeus Primate Survey Rain forest 



We thank the Government of Cameroon’s Ministry of Forestry and Wildlife and Ministry of Research and Technical Innovation for providing research permission as well as supporting this study on the ground. Funding was provided by the Margot Marsh Biodiversity Foundation, the Offield Family Foundation, the US Fish and Wildlife Great Ape Conservation Fund, and the Arcus Foundation, to whom we are very grateful. We thank our entire field teams, in particular Abwe Enang Abwe, Mfossa Daniel, Cletus Arong, Daniel Awoh, and Chris Wild, as well as all the village chiefs and interviewees who assisted with this study. We thank James Higham and two anonymous reviewers who commented on earlier versions of this manuscript.


  1. Astaras, C. (2009). Ecology and status of the drill (Mandrillus leucophaeus) in Korup National Park: Implications for conservation. Ph.D. thesis, Georg-August-Universität Göttingen, Göttingen, Germany. Available at
  2. Brashares, J. S., Golden, C. D., Weinbaum, K. Z., Barrett, C. B., & Okello, G. V. (2011). Economic and geographic drivers of wildlife consumption in rural Africa. PNAS, 108(34), 13931–13936.PubMedCrossRefGoogle Scholar
  3. Center for International Earth Science Information Network (CIESIN), Columbia University; International Food Policy Research Institute (IFPRI); The World Bank; and Centro Internacional de Agricultura Tropical (CIAT). (2004). Global Rural-Urban Mapping Project, Version 1 (GRUMPv1): Population Density Grid. Palisades, NY: Socioeconomic Data and Applications Center (SEDAC), Columbia University. Available at (Accessed October 5, 2011).
  4. Fa, J., Garcia Yuste, J. E., & Castelo, R. (2000). Bushmeat markets on Bioko Island as a measure of hunting pressure. Conservation Biology, 14, 1602–1613.CrossRefGoogle Scholar
  5. Fa, J. E., Peres, C. A., & Meuuwig, J. (2002). Bushmeat exploitation in tropical forests: an intercontinental comparison. Conservation Biology, 16, 232–241.CrossRefGoogle Scholar
  6. Fa, J. E., Seymour, S., Dupain, J., Amin, R., Albrechtsen, L., & Macdonald, D. (2006). Getting to grips with the magnitude of exploitation: bushmeat in the Cross-Sanaga rivers region, Nigeria and Cameroon. Biological Conservation, 129, 497–510.CrossRefGoogle Scholar
  7. Gadsby, E. L. (1992). Drill survey in Cameroon. Oryx, 26(3), 177–178.Google Scholar
  8. Gadsby, E. L., & Jenkins Jr., P. D. (1997–1998). The drill-integrated in situ and ex situ conservation. African Primates, 3(1–2), 12–18.Google Scholar
  9. Gartlan, J. S. (1970). Preliminary notes on the ecology and behavior of the drill, Mandrillus leucophaeus Ritgen, 1824. In J. R. Napier & P. H. Napier (Eds.), Old world monkeys (pp. 445–480). New York: Academic Press.Google Scholar
  10. Grubb, P. (1973). Distribution, divergence and speciation of the drill and mandrill. Folia Primatologica, 20, 161–177.CrossRefGoogle Scholar
  11. Hearn, G. W., & Berghaier, R. W. (1996). Census of diurnal primate groups in the Gran Caldera Volcanica de Luba, Bioko Island, Equatorial Guinea: January, 1996. Report to the Government of Equatorial Guinea.Google Scholar
  12. Hearn, G., & Morra, W. (2001). The approaching extinction of monkeys and duikers on Bioko Island, Equatorial Guinea, Africa. Publication no. 7. Glenside: Arcadia University, Bioko Biodiversity Protection Program.Google Scholar
  13. IEA. (1998). Mandrillus leucophaeus. In African mammals databank: A databank for the conservation and management of the African mammals. Institute of Applied Ecology. Available at:
  14. Macdonald, D. W., Johnson, P. J., Albrechtsen, L., Seymour, S., Dupain, J., Hall, A., & et al. (2011). Bushmeat trade in the Cross-Sanaga rivers region: evidence for the importance of protected areas. Biological Conservation. Available at:
  15. Maley, J. (1991). The African rain forest vegetation and palaeoenvironments during late quaternary. Climatic Change, 19, 79–98.CrossRefGoogle Scholar
  16. Maley, J., & Brenac, P. (1998). Vegetation dynamics, paleoenvironments and climatic changes in the forest of western Cameroon during the last 28,000 years B.P. Review of Paleobotany and Palynology, 99, 157–187.CrossRefGoogle Scholar
  17. Morgan, D., & Sanz, C. (2007). Best practice guidelines for reducing the impact of commercial logging on great apes in western Equatorial Africa. Gland: IUCN/SSC Primate Specialist Group.CrossRefGoogle Scholar
  18. Morgan, B. J., Adeleke, A., Bassey, T., Bergl, R., Dunn, A., Fotso, R., et al. (2011). Regional action plan for the conservation of the Nigeria–Cameroon chimpanzee (Pan troglodytes ellioti). Escondido: IUCN/SSC Primate Specialist Group and Zoological Society of San Diego.Google Scholar
  19. Oates, J. F. (1996). African primates: Status survey and conservation action plan, revised edition. Gland: IUCN/SSC Primate Specialist Group.CrossRefGoogle Scholar
  20. Oates, J. F., & Butynski, T. M. (2008). Mandrillus leucophaeus. In IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. Available at: (Accessed December 18. 2011).
  21. Oates, J. F., Bergl, R. A., & Linder, J. M. (2004). Biodiversity and conservation in the Gulf of Guinea. Advances in Applied Biodiversity Science, no. 6. Washington, DC: Conservation International Center for Applied Biodiversity Science Press.Google Scholar
  22. Olson, D. M., Dinerstein, E., Wikramanayake, E. D., Burgess, N. D., Powell, G. V. N., Underwood, E. C., et al. (2001). Terrestrial ecoregions of the world: a new map of life on earth. Bioscience, 51(11), 933–938.CrossRefGoogle Scholar
  23. Ting, N., Astaras, C., Hearn, G., Honarvar, S., Corush, J., Burrell, A. S., et al. (2012). Genetic signatures of a demographic collapse in a large-bodied forest dwelling primate (Mandrillus leucophaeus). Ecology and Evolution, 2(3), 550–561.PubMedCrossRefGoogle Scholar
  24. Wild, C., Morgan, B. J., & Dixson, A. (2005). Conservation of drill populations in Bakossiland, Cameroon: historical trends and current status. International Journal of Primatology, 26(4), 759–773.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Bethan J. Morgan
    • 1
    • 2
    • 3
  • Ekwoge E. Abwe
    • 3
  • Alan F. Dixson
    • 4
  • Christos Astaras
    • 5
    • 6
  1. 1.Institute for Conservation ResearchZoological Society of San DiegoEscondidoUSA
  2. 2.School of Natural SciencesUniversity of StirlingStirlingScotland
  3. 3.Ebo Forest Research ProjectMessaCameroon
  4. 4.School of Biological SciencesVictoria University of WellingtonWellingtonNew Zealand
  5. 5.Centre for Nature Conservation, Department of Conservation BiologyGeorg-August-Universität GöttingenGöttingenGermany
  6. 6.Wildlife Conservation Research Unit, Recanati-Kaplan Centre, Department of ZoologyUniversity of OxfordTubneyUK

Personalised recommendations