Eastern Chimpanzee
Pan troglodytes schweinfurthii is one of four recognized subspecies of robust chimpanzee. It has a geographic range that spans the Ubangi River/Congo River in Central African Republic (CAR) and Democratic Republic of Congo (DRC), to western Uganda, Rwanda and western Tanzania. There are also small isolated populations in Burundi and south-eastern South Sudan (Plumptre et al. 2010). Their numbers are thought to have been previously underestimated and population modelling indicates a total population size of 200,000–250,000 individuals (Plumptre et al. 2010). There is a dearth of survey information from some countries, such as South Sudan, due to years of civil war. Despite persisting insecurity, camera-trap studies have enabled researchers in Chinko, CAR, to estimate that 910 chimpanzees live in the project area, and predict that a further 2,700 individuals may inhabit adjacent hunting zones (Aebischer et al. 2017).The eastern chimpanzee is classified as Endangered on the IUCN Red List of Threatened Species (Plumptre et al. 2016) indicating that it has a high risk of extinction in the wild.
Threats
The four subspecies of P. troglodytes face similar threats to varying degrees in different regions. The major threats to the survival of eastern chimpanzees are illegal hunting for bushmeat, habitat loss and fragmentation, and disease transmission (Plumptre et al. 2016). Chimpanzees occur at low densities across their range, and with their slow reproductive rates (one infant born every 4–5 years), they take a long time to recover from any reduction in numbers.
Poaching occurs across their geographic range, but is particularly intense in CAR and DRC, where they are targeted for the commercial bushmeat trade (chimpanzees are larger than other primates, so provide more meat). Bushmeat poaching in CAR is exacerbated by well-armed South Sudanese and Sudanese poachers and militia, inadequate capacity to implement law and order, and high levels of poverty (e.g., Ondoua Ondoua et al. 2017). When chimpanzee females with infants are killed, their offspring are often kept alive and traded as pets. Although such trade is illegal in all range countries that are signatories to CITES, it persists across Africa. DRC has been identified as a key source country of live infants being illegally traded in the region (Hicks et al. 2010).
Chimpanzee habitat is gradually being fragmented by roads and human settlements. Roads are constructed to link settlements and/or for the removal of timber, facilitating access of hunters to previously remote areas and better transportation routes. In East Africa (including Tanzania, Rwanda and Burundi), there is little to no killing of chimpanzees for bushmeat, but their populations are declining due to habitat loss and degradation as land is converted for agriculture. People sometimes kill chimpanzees to protect their crops, or in retribution for crop raiding (Hockings & Humle 2009). They may also be maimed or killed unintentionally when caught in snares set for other animals (Gilardi et al. 2015).
There is a great risk of disease transmission in East Africa as chimpanzee populations often live in close proximity to humans. Human gut fauna are found in chimpanzees and other primates in Kibale National Park that live adjacent to human settlements, and similarities between the gut fauna of people and primates increases with increasing forest fragmentation (Plumptre et al. 2010). This is further exacerbated by tourism in several East African countries, where tourists can come within 7–10 metres to habituated chimpanzees. Given the use of tourism in chimpanzee conservation, strict guidelines have been developed to minimise the risks of disease transmission (Macfie & Williamson 2010).
Conservation
This subspecies is probably the best known due to long-term behavioural and ecological research undertaken at Gombe National Park (began by Jane Goodall), in the Mahale National Mountains Park (started by Toshisada Nishida), at Kibale Forest, Uganda (led by Richard Wrangham), and in Budongo Forest Reserve, also in Uganda (initiated by Vernon Reynolds). To address their population decline, experts were convened in 2009 to develop a 10-year action plan for the subspecies. The aim of the plan was to produce strategies to reduce (or halt) the decline of eastern chimpanzees across their range by identifying key populations and priority conservation actions. All available data on the distribution and density of this subspecies were collated, a priority setting process undertaken. Projects tackling the greatest threats (poaching, habitat loss and degradation, and lack of law enforcement) were given the highest priority, as they are likely to have the conservation greatest impact.
Priority actions were grouped as follows: (1) policy and legislation (creation of protected areas where needed; country-specific conservation plans where they do not already exist i.e., CAR and Sudan; implementation of guidelines for regulations with habituated chimpanzees; revision of land-use plans and implementation of village land-use plans); (2) species and habitat (strengthening law enforcement i.e., increasing surveillance, eco guards and judiciary efficiency; restoration of degraded habitat); (3) monitoring and research (e.g., study of the distribution and drivers of poaching of chimpanzees; training to build capacity in survey and monitoring methodology; standardised health monitoring implemented for habituated communities); (4) public awareness and training (e.g., development of environmental materials for teachers; production and dissemination of materials to enhance community awareness and inform people about existing laws; (5) community involvement (development of ecotourism projects; conservation management programmes to incorporate local community employment); projects to supply alternative protein sources and replace bushmeat; (6) sustainable finance (business plans for conservation area).
Successful implementation of the action plan could conserve about 96% of known eastern chimpanzee populations, and capture the range of ecological and cultural variation that exists within the subspecies (Plumptre et al. 2010).
References
Aebischer, T., Siguindo, G., Rochat, E., Arandjelovic, M., Heilman, A., Hickisch, R., Vigilant, L., Joost, S. & Wegmann, D. (2017). First quantitative survey delineates the distribution of chimpanzees in the eastern Central African Republic. Biological Conservation 213: 84–94.
Gilardi, K.V., Gillespie, T.R., Leendertz, F.H., Macfie, E.J., Travis, D.A., Whittier, C.A. & Williamson, E.A. (2015). Best Practice Guidelines for Health Monitoring and Disease Control in Great Ape Populations. IUCN SSC Primate Specialist Group, Gland, Switzerland [published in English, French & Bahasa Indonesia].
Hicks, T.C., Darby, L., Hart, J., Swinkels, J., van Hooff, J., January, N. & Menken, S. (2010). Trade in orphans and bushmeat threatens one of the Democratic Republic of the Congo’s most important populations of eastern chimpanzees, Pan troglodytes schweinfurthii. African Primates 7: 1–18.
Hockings, K. & Humle, T. (2009). Best Practice Guidelines for the Prevention and Mitigation of Conflict Between Humans and Great Apes. IUCN SSC Primate Specialist Group, Gland, Switzerland [published in English, French & Bahasa Indonesia].
Macfie, E.J. & Williamson, E.A. (2010). Best Practice Guidelines for Great Ape Tourism. IUCN SSC Primate Specialist Group, Gland, Switzerland [published in English, French & Bahasa Indonesia].
Ondoua Ondoua, G., Beodo Moundjim, E., Mambo Marindo, J.C., Jiagho, R., Usongo, L. & Williamson, L. (2017). An Assessment of Poaching and Wildlife Trafficking in the Garamba-Bili-Chinko Transboundary Landscape. TRAFFIC, Cambridge, UK. http://www.traffic.org/
Plumptre, A., Hart, J.A., Hicks, T.C., Nixon, S., Piel, A.K. & Pintea, L. (2016). Pan troglodytes ssp. schweinfurthii. The IUCN Red List of Threatened Species 2016: e.T15937A17990187.
Plumptre, A.J., Nixon, S., Critchlow, R., Vieilledent, G., Nishuli, R., Kirkby, A., Williamson, E.A., Hall, J.S. & Kujirakwinja, D. (2015). Status of Grauer’s Gorilla and Chimpanzee in Eastern Democratic Republic of Congo: Historical and Current Distribution and Abundance. Wildlife Conservation Society, Fauna & Flora International and Institut Congolais pour la Conservation de la Nature, New York. http://www.albertinerift.org/about-us/publications.aspx
Plumptre, A.J., Rose, R., Nangendo, G., Williamson, E.A., Didier, K., Hart, J., Mulindahabi, F., Hicks, C., Griffin, B., Ogawa, H., Nixon, S., Pintea, L., Vosper, A., McClennan, M., Amsini, F., McNeilage, A., Makana, J.R., Kanamori, M., Hernandez, A., Piel, A., Stewart, F., Moore, J., Zamma, K., Nakamura, M., Kamenya, S., Idani, G., Sakamaki, T., Yoshikawa, M., Greer, D., Tranquilli, S., Beyers, R., Furuichi, T., Hashimoto, C. & Bennett, E. (2010). Eastern Chimpanzee (Pan troglodytes schweinfurthii): Status Survey and Conservation Action Plan 2010–2020. IUCN SSC Primate Specialist Group, Gland, Switzerland [published in English & French]