Western Species (Gorilla gorilla)
Both the western lowland gorilla and the Cross River gorilla are threatened by bushmeat hunting and habitat loss. In the Congo basin these threats are particularly due to commercial logging, which accelerates habitat loss and increases access to remote areas, facilitating hunting (Wilkie et al 2000). Western lowland gorillas have also been significantly impacted by a series of Ebola outbreaks in recent years. These outbreaks may have reduced the gorilla population by as much as 90% in some areas and are estimated to have reduced the entire Gabon population by 50% (Walsh 2003).
Cross River gorillas have, to date, not been affected by the Ebola epidemic. However, intense hunting over many years has lead to a small and fragmented population of gorillas. The current concentration of the Cross River gorillas in rugged highland areas is likely a direct result of hunting pressure, as these areas are extremely difficult for hunters to access. The small size and potential fragmentation of the population could potentially expose the gorillas to inbreeding, which would have serious negative consequences for the long-term survival of these animals.
As a result of the above threats, The World Conservation Union (IUCN) classifies both western lowland gorillas and Cross River gorillas as Critically Endangered. The Cross River gorillas are the most endangered ape in Africa.
In response to the threats faced by these gorillas, conservationists from around the world have recently produced action plans for the conservation of both western lowland gorillas (Tutin et al., 2005) and Cross River gorillas (Oates et al., 2007). These plans provide specific strategies for addressing the many challenges to the continued survival of western gorillas. Examples of these strategies include building capacity in national organizations to allow enforcement of existing wildlife laws, developing alternative livelihood strategies for those who depend on hunting or forest products, purchasing or leasing land for conservation, ecotourism, continued conservation-relevant research, and implementation of controls to halt the spread of Ebola. Copies of the action plans are available from:
- Text by Richard Bergl, Ph.D.
Eastern Species (Gorilla beringei)
Despite recent increases in numbers, both mountain gorilla populations face serious threats to their survival from habitat loss for agriculture and extraction of resources (cattle grazing, firewood collection, poaching for smaller animals; Mehlman 2007). In addition, poaching, a serious problem in the 1960s and 1970s, has again become of considerable concern. In 2007 alone, 10 mountain gorillas were killed in the Democratic Republic of Congo. A final threat is disease. Both populations live in some of the highest human densities found in Africa, and there are no buffer zones between human settlements and park boundaries. As a result, gorillas are susceptible to diseases transmitted by local populations and their livestock. In addition, both populations are visited daily by tourists, which represent another potential method of disease cross transmission (MGVP, Inc. & WCS, 2007).
Grauer's gorillas are threatened by habitat loss and fragmentation for agricultural expansion. In addition, mining for gold, diamonds, and ores such as coltan and cassiterite (used in small electronics like cell phones) has a considerable impact on gorilla habitat as mining practices result in both direct and indirect environmental damage through forest clearance, stream pollution, erosion, firewood cutting, tree debarking (panning trays), liana cutting, disturbance to freshwater ecology, and bushmeat hunting (Mehlman, 2007).
Conservation programs are widespread throughout the eastern gorilla range. In addition to the work of the national parks services of the three habitat countries (Rwanda Office of Tourisme and National Parks (ORTPN); Uganda Wildlife Authority, and Institut Congolais pour la Conservation de la Nature (ICCN), Democratic Republic of Congo), a host of NGOs are involved in conservation activities including research, anti-poaching patrols, and support programs for local communities which include education, health and microfinance initiatives. In addition, the funds generated by ecotourism programs contribute significantly towards the protection of the gorillas and their habitats.
- Text by Tara S. Stoinski, Ph.D.
Mehlman, P.T. 2007. Current status of wild gorilla populations and strategies for their conservation. In Stoinski, T.S., Steklis, H.D. & Mehlman, PT, eds. Conservation in the 21st Century: Gorillas as a Case Study. New York: Springer, pp. 3-54.
Mountain Gorilla Veterinary Project (MGVP, Inc.) & Wildlife Conservation Society (WCS). 2007. Conservation medicine for gorilla conservation. In Stoinski, T.S., Steklis, HD& Mehlman, PT, eds. Conservation in the 21st Century: Gorillas as a Case Study. New York: Springer, pp. 57-78.
Oates, J., Sunderland-Groves, J., Bergl, R., Dunn, A., Nicholas, A., Takang, E., Omeni, F., Imong, I., Fotso, R., Nkembi, L. and Williamson, L. 2007. Regional Action Plan for the Conservation of the Cross River Gorilla (Gorilla gorilla diehli). IUCN/SSC Primate Specialist Group and Conservation International, Arlington, VA, USA.
Tutin, C., Stokes, E., Boesch, C., Morgan, D., Sanz, C., Reed, T., Blom, A., Walsh, P., Blake, S., Kormos, R. 2005. Regional Action Plan for the Conservation of Chimpanzees and Gorillas in Western Equatorial Africa. Conservation International. Washington, DC.
Walsh, P.D., Abernethy, K. A., Bermejo, M., Beyers, R., De Wachter, P., Akou, M. E. Huijbregts, B., Mambounga, D. I., Toham, A. K., Kilbourne, A. M., Lahm, S. A., Latour, S., Maisels, F., Mbina, C., Mihindou, Y., Obiang, S. N., Effa, E. N., Stakey, 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.
Wilkie, D.S., Shaw, E., Rotberg, F., Moreilli, G. & Auzel, P. 2000. Roads, development, and conservation in the Congo Basin. Conservation Biology 14: 1614-1622.