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Will the Nigeria-Cameroon Chimpanzee Go Extinct? Models Derived from Intake Rates of Ape Sanctuaries

Part of the Developments in Primatology: Progress and Prospects book series (DIPR,volume 35)

Abstract

All great ape taxa are considered endangered due to a combination of habitat loss, hunting, disease outbreaks and human population increase. The bush-meat trade is thought to be the biggest threat to the survival of chimpanzees, bonobos and gorillas. However, assessments of the reduction of wild populations are notoriously unreliable since they are mostly based on indirect evidence such as brief surveys of markets and interviews with hunters. We use a direct approach and measure annual loss from the wild through intake rates of sanctuaries in Africa which currently hold close to 1000 apes. From these, we calculate loss to the wild populations by relating arrivals into sanctuaries to the proportions of infants in wild groups, hunting strategies, and the likelihood that captured babies make it to a sanctuary. We focus on the most endangered chimpanzee subspecies, Pan troglodytes vellerosus, found in eastern Nigeria / western Cameroon. Our calculations, based on intake rates since 1986 into four sanctuaries in Cameroon and Nigeria, suggest that current rates of hunting are 2 – 13 times higher than sustainable rates. Moreover, VORTEX – a population viability analysis tool – predicts that this chimpanzee subspecies will go extinct in as little as 20 years. The dramatic results emphasise the need for immediate conservation measures. Ape sanctuaries are, at times, considered to be a waste of resources, which could be better diverted to habitat protection. However, it is extremely unlikely that hunting pressure can be significantly reduced, and many local ape populations are already effectively extinct. Sanctuaries will therefore play an increasingly important role as ape conservation tools, if only for the fact that they may, in a couple of decades, harbour more apes than survive in the wild. We propose to apply our method of measuring extinction risk to other taxa of apes across Africa and Asia.

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Literature

  • Adanu, J. (1997). Determination of Life-span of Chimpanzee Nests (Nest-aging) in Gashaka-Gumti National Park. Report to NCF & WWF-UK.

    Google Scholar 

  • Akçakaya, H. R. (1998). RAMAS metapop: Viability analysis for stage-structured metapopulations, Version 3.0. Software Program.

    Google Scholar 

  • Ammann, K. (2001). Bushmeat hunting and the great apes. In Beck, B. B., Stoinski, T. S., Hutchins, M., Maple, T. L., Norton, B., Rowan, A., Stevens, E. F. & Arluke, A. (eds.), Great Apes and Humans: the Ethics of Co-existence. Washington: Smithsonian Institution Press, pp. 71–85.

    Google Scholar 

  • Ammann, K. & Pearce, J. (1995). Slaughter of the Apes: How the Tropical Timber Industry is Devouring Africa’s Great Apes. London: WSPA.

    Google Scholar 

  • Baillie, J. E. M., Hilton-Taylor, C. & Stuart, S. (2004). IUCN Red List of Threatened Species: A Global Species Assessment. Gland, Switzerland & Cambridge / UK: IUCN.

    Google Scholar 

  • Beck, J. & Chapman, H. (2008). A population estimate of the endangered chimpanzee Pan troglodytes vellerosus in a Nigerian montane forest: implications for conservation. Oryx 42: 448–451.

    Article  Google Scholar 

  • Boesch, C. & Boesch-Achermann, H. (2000). The Chimpanzees of the Taï Forest. Behavioural Ecology and Evolution. Oxford: Oxford University Press.

    Google Scholar 

  • Bowen-Jones, E. (1998). A Review of the Commercial Bushmeat Trade with Emphasis on Central / West Africa and the Great Apes. Cambridge / UK: Flora and Fauna International.

    Google Scholar 

  • Bowen-Jones, E. & Pendry, S. (1999). The threat to primates and other mammals from the bushmeat trade in Africa, and how this threat could be diminished. Oryx 33: 233–246.

    Google Scholar 

  • Butynski, T. M. (2001). Africa’s great apes. In Beck, B. B., Stoinski, T. S., Hutchins, M., Maple, T. L., Norton, B., Rowan, A., Stevens, E. F. & Arluke, A. (eds.), Great Apes and Humans: the Ethics of Co-Existence. Washington: Smithsonian Institution Press, pp. 3–56.

    Google Scholar 

  • Butynski, T. M. & Kalina, J. (1998). Gorilla tourism: a critical look. In Milner-Gullard, E. J. & Mace, R. (eds.), Conservation of Biological Resources. Oxford: Blackwell, pp. 280–300.

    Google Scholar 

  • Caldecott, J. & Miles, L. (ed.) (2005). World Atlas of Great Apes and Their Conservation. Los Angeles: University of California Press.

    Google Scholar 

  • Campbell, G., Kuehl, H., N’Goran Kuamé, P. & Boesch, C. (2008). Alarming decline of West African chimpanzees. Current Biology 18: R903–R904.

    Article  CAS  PubMed  Google Scholar 

  • Cavalieri, P. & Singer, P. (ed.) (1993). The Great Ape Project. Equality Beyond Humanity. New York: St. Martin’s Press.

    Google Scholar 

  • Chapman, C. A. & Peres, C. A. (2001). Primate conservation in the new millennium: the role of scientists. Evolutionary Anthropology 10: 16–33.

    Article  Google Scholar 

  • Chapman, C. A., Wrangham, R. & Chapman, L. J. (1994). Indices of habitat-wide fruit abundance in tropical forests. Biotropica 26: 160–171.

    Article  Google Scholar 

  • Cowlishaw, G. & Dunbar, R. (2000). Primate Conservation Biology. Chicago: The University of Chicago Press.

    Google Scholar 

  • Cole, L. C. (1954). The population consequences of life history phenomena. The Quarterly Review of Biology 29: 103–137.

    Article  CAS  PubMed  Google Scholar 

  • De Merode, E., Homewood, K. & Cowlishaw, G. (2004). The value of bushmeat and other wild foods to rural households living in extreme poverty in Democratic Republic of Congo. Biological Conservation 118: 573–581.

    Article  Google Scholar 

  • Dunn, A. (1993). The Large Mammals of Gashaka-Gumti National Park, Nigeria: Line Transect Surveys from Forest and Savannah. Report to WWF-UK, NCF & Federal Ministry of Agriculture, Water Resources and Rural Development / Nigeria.

    Google Scholar 

  • Dunn, A. (1999). Gashaka Gumti National Park: a Guidebook. Lagos: Gashaka Gumti National Park, NCF / WWF-UK.

    Google Scholar 

  • Edroma, E. L., Rosen, N. & Miller, P. S. (1997). Conserving the Chimpanzees of Uganda: Population and Habitat Viability Assessment for Pan troglodytes schweinfurthii. Apple Valley, Minnesota: IUCN / SSC Conservation Breeding Specialist Group.

    Google Scholar 

  • Fa, J. E. & Purvis, A. (1997). Body size, diet and population density in Afrotropical forest mammals: a comparison with neotropical species. Journal of Animal Ecology 66: 98–112.

    Article  Google Scholar 

  • Fa, J. E., Currie, D. & Meeuwig, J. (2003). Bushmeat and food security in the Congo Basin: linkages between wildlife and people’s future. Environmental Conservation 30: 71–78.

    Article  Google Scholar 

  • Fa, J. E., Garcia Yuste, J. E. & Castelo, R. (2000). Bushmeat markets on Bioko island as a measure of hunting pressure. Conservation Biology 14: 1602–1613.

    Article  Google Scholar 

  • Fa, J. E., Peres, C. A. & Meeeuwig, J. (2002). Bushmeat exploitation in tropical forests: an intercontinental comparison. Conservation Biology 16: 232–237.

    Article  Google Scholar 

  • Foster, K. L. (1998). Censusing Chimpanzees in Gashaka-Gumti National Park, Taraba and Adamawa States, Nigeria. Report to WWF-UK, NCF & Federal Ministry of Agriculture, Water Resources and Rural Development / Nigeria.

    Google Scholar 

  • Fowler, A. (2006). Socio-ecology of Nigerian Chimpanzees at Gashaka. PhD thesis, University of London.

    Google Scholar 

  • Fowler, A & Sommer, V. (2007). Subsistence technology in Nigerian chimpanzees. International Journal of Primatology 28: 997–1023.

    Article  Google Scholar 

  • Gonder, M. K., Oates, J. F., Disotell, T. R., Forstner, M. R. J., Morales, J. C. & Melnick, D. J. (1997). A new West African chimpanzee subspecies? Nature 338: 337.

    Article  Google Scholar 

  • Goodall, J. (1986). The Chimpanzees of Gombe: Patterns of Behaviour. Cambridge, MA: Harvard University Press.

    Google Scholar 

  • Hill, K., Boesch, C., Goodall, J., Pusey, A., Williams, J. & Wrangham, R. W. (2001). Mortality rates among wild chimpanzees. Journal of Human Evolution 40: 437–450.

    Article  CAS  PubMed  Google Scholar 

  • Hogarth, S. A. (1997). The Distribution and Abundance of the Chimpanzees (Pan troglodytes troglodytes) of the Lowland Gallery Forest of Gashaka-Gumti National Park Nigeria: A Preliminary Report to the Gashaka Sector. Report to WWF-UK, NCF & Federal Ministry of Agriculture, Water Resources and Rural Development / Nigeria.

    Google Scholar 

  • Hughes, N. (2003). Great Ape Sanctuaries in Nigeria and Cameroon: a Window into the Bushmeat-Trade. MSc in Human Evolution and Behaviour thesis, University College London.

    Google Scholar 

  • Inskipp, T. (2005). Chimpanzee (Pan troglodytes). In Caldecott, J. & Miles, L. (eds.), World Atlas of Great Apes and Their Conservation. Los Angeles: University of California Press, pp. 53–81.

    Google Scholar 

  • IUCN (2007). IUCN Red List of Threatened Species. Gland / Switzerland & Cambridge / UK: IUCN / SSC.

    Google Scholar 

  • Kemf, E. & Wilson, A. (1997). Great Apes in the Wild. Gland: WWF.

    Google Scholar 

  • Kormos, R., Boesch, C., Bakarr, M. I. & Butynski, T. M. (eds.) (2003). West African Chimpanzees. Status Survey and Conservation Action Plan. Gland & Cambridge UK: IUCN / SSC Primate Specialist Group.

    Google Scholar 

  • Lacy, R., M. Borbat & Pollack, J. (2003). VORTEX: A Stochastic Simulation of the Extinction Process. Version 9 User’s Manual. Apple Valley / Minnesota: Conservation Breeding Specialist Group (SSC / IUCN).

    Google Scholar 

  • Lameed, G. A. (2002). Chimpanzee (Pan troglodytes) population density and structure in Gashaka Gumti National Park. ROAN: The Journal of Conservation 1: 88–93.

    Google Scholar 

  • Leendertz, F., Ellerbock, H. Boesch, C., Couacy-Hymann, E., Mätz-Rensing, K., Hakenback, R., Bergmann, C., Abaza, P. Junglen, S., Moebius, Y., Vigilant, L., Formenty, P. Pauli, G. (2004). Anthrax kills wild chimpanzees in a tropical rainforest. Nature 430: 451–452.

    Article  CAS  PubMed  Google Scholar 

  • MacKinnon, J. 1977. The future of orang-utans. New Scientist 74: 697–699.

    Google Scholar 

  • Matthews, A. & Matthews, A. (2004). Survey of Gorillas (Gorilla gorilla gorilla) and ­chimpanzees (Pan troglodytes troglodytes) in Southwestern Cameroon. Primates 45: 15–24.

    Article  PubMed  Google Scholar 

  • McManus, E. (2005). Federal Republic of Nigeria. In Caldecott, J. & Miles, L. (eds.), World Atlas of Great Apes and Their Conservation. Los Angeles: University of California Press, pp. 378–383.

    Google Scholar 

  • Miller, P. S. & Lacey, R. C. (1997). VORTEX: A Stochastic Simulation of the Extinction Process. Version 8 User’s Manual. Apple Valley / Minnesota: Conservation Breeding Specialist Group (SSC / IUCN).

    Google Scholar 

  • Milner-Gullard, E. J. & Akçakaya, H. R. 2001. Sustainability indices for exploited populations. Trends in Ecology and Evolution 18: 686–692.

    Article  Google Scholar 

  • Mittermeier, R. & Cheney, D. (1987). Conservation of primates and their habitats. In Smuts, B. B., Cheney, D. L., Seyfarth, R. M., Wrangham, R. W. & Struhsaker, T. T. (eds.), Primate Societies. Chicago: The University of Chicago Press, 477–490.

    Google Scholar 

  • Morgan, B. J & Abwe, E. E. (2006). Chimpanzees use stone hammers in Cameroon. Current Biology 16: R632–R633.

    Article  CAS  PubMed  Google Scholar 

  • Morin, P. A. (1993). Reproductive strategies in chimpanzees. Yearbook of Physical Anthropology 36: 179–212.

    Article  Google Scholar 

  • Ngalla, P. T., Miles, L. & Caldecott, J. (2005). Republic of Cameroon. In Caldecott, J. & Miles, L. (eds.), World Atlas of Great Apes and Their Conservation. Los Angeles: University of California Press, pp. 305–314.

    Google Scholar 

  • Oates, J. F. (2006) Is the chimpanzee, Pan troglodytes, an endangered species? It depends on what endangered means. Primates 47: 102–112.

    Article  PubMed  Google Scholar 

  • Oates, J. F., Groves, C. & Jenkins, P. D. (2008). The type locality of Pan troglodytes vellerosus (Gray, 1862), and implications for the nomenclature of West African chimpanzees. Primates 50: 78–80.

    Article  PubMed  Google Scholar 

  • Peres, C. A. (1991). Humboldt’s woolly monkeys decimated by hunting in Amazonia. Oryx 25: 89–95.

    Google Scholar 

  • Peterson, D. & Ammann, K. (2003). Eating Apes. California: University of California Press.

    Google Scholar 

  • Peterson, D. & Goodall, J. (1993). Visions of Caliban: on chimpanzees and people. Boston: Houghton Mifflin Company.

    Google Scholar 

  • Robinson, J. G. & Redford, K. H. (1991). Neotropical wildlife use and conservation. Chicago: The University of Chicago Press.

    Google Scholar 

  • Rose, A. L. (1998). Finding paradise in a hunting camp: turning poachers to protectors. Journal of the Southwestern Anthropological Association 38: 4–11.

    Google Scholar 

  • Rose, A. L., Mittermeier, R. A., Langrand, O., Ampadu-Agyei, O., Butynski, T. M. & Ammann, K. (2003). Consuming Nature. A photo essay on African rain forest exploitation. Palos Verdes, CA: Altisima.

    Google Scholar 

  • Rosen, N., Cox, D., Montgomery, C. & Cress, D. (2002). Pan African Sanctuaries Alliance (PASA) Workshop Report. Apple Valley / Minnesota: Conservation Breeding Specialist Group (SSC / IUCN).

    Google Scholar 

  • Rosen, N., Seal, U. S., Cox, D., Montgomery, C. Boardman, W. (2001). Pan African Sanctuary Alliance (PASA) Workshop Report. Apple Valley / Minnesota: Conservation Breeding Specialist Group (SSC / IUCN).

    Google Scholar 

  • Ross, C. (1992). Environmental correlates of the intrinsic rate of natural increase in primates. Oecologica 90: 383–390.

    Article  Google Scholar 

  • Slade, N. A., Gomulkiewicz, R. & Alexander, H. M. (1998). Alternatives to Robinson and Redford’s method for assessing over harvest from incomplete demographic data. Conservation Biology 12: 148–155.

    Article  Google Scholar 

  • Soave, O. (1982). The rehabilitation of chimpanzees and other apes. Laboratory Primate Newsletter 21: 3–8.

    Google Scholar 

  • Sommer, V. (2008). Schimpansenland. Wildes Leben in Afrika. Munich: C. H. Beck.

    Google Scholar 

  • Sommer, V. & Ammann, K. (1998). Die Großen Menschenaffen: Orang-utan, Gorilla, Schimpanse, Bonobo. Munich: BLV.

    Google Scholar 

  • Sommer, V., Adanu, J., Faucher, I. & Fowler, A. (2004). The Nigerian Chimpanzee (Pan troglodytes vellerosus) at Gashaka: Two years of habituation efforts. Folia Primatologica 75: 295–316.

    Article  Google Scholar 

  • Teleki, G. (1980). Hunting and Trapping Wildlife in Sierra Leone: Aspects of Exploitation and Exportation. Washington: WWF.

    Google Scholar 

  • Teleki, G. (1989). Population status of wild chimpanzees (Pan troglodytes) and threats to survival. In Heltne, P. G. & Marquardt, L. A. (eds.), Understanding Chimpanzees. Cambridge: Harvard University Press, pp. 312–353.

    Google Scholar 

  • Teleki, G. (2001). Sanctuaries for great ape refugees. In Beck, B. B., Stoinski, T. S., Hutchins, M., Maple, T. L., Norton, B., Rowan, A., Stevens, E. F. & Arluke, A. (eds.), Great Apes and Humans: The Ethics of Co-Existence. Washington: Smithsonian Institution Press, pp. 133–149.

    Google Scholar 

  • The Sunday Times (1999). Chimps on the menu in Brussels restaurants. 16th May.

    Google Scholar 

  • Tutin, C. E. G., Ancrenaz, M., Paredes, J., Vacher-Vallas, M., Vidal, C., Goossens, B., Bruford, M. W. & Jamart, A. (2001). Conservation biology framework for the release of wild-born orphaned chimpanzees into the Conkouati Reserve, Congo. Conservation Biology 15: 1247–1257.

    Article  Google Scholar 

  • Walsh, P. D., Abernathy, K. A., Bermejo, M., Beyers, R., De Wachter, P., Akou, E. M., Huijbregts, B., Mambounga, DI, Toham, A. K., Kilbourn, A. M., Lahm, S. A., Latour, S., Maisels, F., Mbina, C., Mihindou, Y., Obiang, S. N., Effa E. N., Starkey, M. P., Telfer, P., Thibault, M., Tutin, C. E. G., White, L. J. T. & Wilkie, D. S. (2003). Catastrophic ape decline in western equatorial Africa. Nature 422: 611–614.

    Article  CAS  PubMed  Google Scholar 

  • Werikhe, S., Macfie, L., Rosen, N. & Miller, P. (1998). Can the Mountain Gorilla Survive? Population and Habitat Viability Assessment Workshop for Gorilla gorilla beringei. Conservation Breeding Specialist Group. Minnesota: Apple Valley.

    Google Scholar 

  • Whiten A., Goodall, J., McGrew, W. C., Nishida, T., Reynolds, V., Sugiyama, Y., Tutin, C. E. G, Wrangham, R. W. & Boesch, C. (1999). Cultures in chimpanzees. Nature 399: 682–685.

    Article  CAS  PubMed  Google Scholar 

  • Wilkie, D. S. & Carpenter, J. F. (1999). Bushmeat hunting in the Congo Basin: an assessment of impacts and options for mitigation. Biodiversity and Conservation 8: 927–955.

    Article  Google Scholar 

  • Wilkie, D. S. (2001). Bushmeat trade in the Congo Basin. In Beck, B. B., Stoinski, T. S., Hutchins, M., Maple, T. L., Norton, B., Rowan, A., Stevens, E. F. & Arluke, A. (eds.), Great Apes and Humans: the Ethics of Co-Existence. Washington: Smithsonian Institution Press, pp. 86–109.

    Google Scholar 

  • Wilkie, D. S. & Godoy, R. A. (2001). Income and price elasticities of bushmeat demand in lowland Amerindian societies. Conservation Biology 15: 761–769.

    Article  Google Scholar 

  • Williams, J. M., Liu, H. Y. & Pusey, A. E. (2002). Costs and benefits of grouping for female chimpanzees at Gombe. In Boesch, C., Hohmann, G. & Marchant, L. F. (eds.), Behavioural Diversity in Chimpanzees and Bonobos. Cambridge: Cambridge University Press, pp. 192–203.

    Chapter  Google Scholar 

  • World Bank (2002). World Development Indicators 2002.

    Google Scholar 

  • Wrangham, R. W. (2002). The cost of sexual attraction: is there a trade-off in female Pan between sex appeal and received coercion? In Boesch, C., Hohmann, G. & Marchant, L. F. (eds.), Behavioural Diversity in Chimpanzees and Bonobos. Cambridge: Cambridge University Press, pp. 204–215.

    Chapter  Google Scholar 

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Hughes, N., Rosen, N., Gretsky, N., Sommer, V. (2011). Will the Nigeria-Cameroon Chimpanzee Go Extinct? Models Derived from Intake Rates of Ape Sanctuaries. In: Sommer, V., Ross, C. (eds) Primates of Gashaka. Developments in Primatology: Progress and Prospects, vol 35. Springer, New York, NY. https://doi.org/10.1007/978-1-4419-7403-7_14

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