Pan troglodytes ssp. ellioti 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Primates Hominidae

Scientific Name: Pan troglodytes ssp. ellioti (Matschie,1914)
Parent Species:
Common Name(s):
English Nigeria-Cameroon Chimpanzee
Taxonomic Source(s): Mittermeier, R.A., Rylands, A.B. and Wilson D.E. 2013. Handbook of the Mammals of the World: Volume 3 Primates. Lynx Edicions, Barcelona.
Taxonomic Notes:

The Nigeria-Cameroon Chimpanzee (Pan troglodytes ellioti), until recently known as P. t. vellerosus, occurs in Cameroon, west of the Sanaga River, and Nigeria (Gonder et al. 2006, Oates et al. 2009). Substantial genetic data indicate that P. t. ellioti groups evolutionarily with P. t. verus, while P. t. troglodytes and P. t. schweinfurthii form a second grouping (Prado-Martinez et al. 2013, Mitchell et al. 2015). Pan t. verus and P. t. ellioti separated from one another much earlier than did P. t. troglodytes and P. t. schweinfurthii. The degree of connectivity between Chimpanzee populations in western Nigeria and those in eastern Nigeria and western Cameroon has yet to be adequately examined. Published relationship trees based on analyses of mitochondrial DNA do not group western Nigerian Chimpanzees closely with those of either Upper Guinea or eastern Nigeria (Gonder et al. 2006); however, those analyses were based on a very small number of western Nigerian samples. A more comprehensive analysis using additional samples is urgently needed.

Assessment Information [top]

Red List Category & Criteria: Endangered A4cd ver 3.1
Year Published: 2016
Date Assessed: 2015-11-20
Assessor(s): Oates, J.F., Doumbe, O., Dunn, A., Gonder, M.K., Ikemeh, R., Imong, I., Morgan, B.J., Ogunjemite, B. & Sommer, V.
Reviewer(s): Williamson, E.A. & Mittermeier, R.A.
Contributor(s): Butynski, T.M. & Greengrass, E.J.

Pan t. ellioti has the smallest geographic range and the smallest population of all the Chimpanzee subspecies. It qualifies for Endangered status based on an inferred population size reduction exceeding 50% but less than 80% over a three-generation period from the mid-1980s to 2060 (generation time estimated to be 25 years). This reduction has not ceased, and is not easily reversible, therefore satisfying criterion A. Population reduction is being caused by human activities in a region of dense and increasing human population; these activities are reducing the extent and quality of Chimpanzee habitat (criterion 4c), and include the continuing exploitation of Chimpanzees through illegal hunting (criterion 4d) (Morgan et al. 2011). Habitat is being lost and fragmented by farming, logging, fire and the spread of commercial plantations. Although taboos protect some Chimpanzee subpopulations, poaching (for the bushmeat trade and to provide traditional medicines) is a serious threat over most of the subspecies’ range. Conservation efforts directed at Chimpanzees and other wildlife have increased significantly in many parts of their range over the last 20 years, and P. t. ellioti occurs in several important protected areas including Gashaka-Gumti National Park, Cross River National Park and Afi Mountain Wildlife Sanctuary in Nigeria, and Mbam and Djerem National Park, Korup National Park, Takamanda National Park, Mount Cameroon National Park, Banyang-Mbo Wildlife Sanctuary and the proposed Ebo National Park in Cameroon (Morgan et al. 2011). Management effectiveness varies across these protected areas; in most of them, poaching for bushmeat occurs, sometimes at high levels. Within its larger range, P. t. ellioti is most seriously threatened in two subregions: southwestern Nigeria and northwestern Cameroon. In each of these subregions, total Chimpanzee population numbers are very small (probably less than 250), suitable habitat is highly fragmented, and hunting pressure is intense; population reductions exceeding 80% are likely in the 1985–2060 period, justifying a Critically Endangered rating for P. t. ellioti at a subregional level (Greengrass 2009, Ogunjemite 2011, Ikemeh 2013, O. Doumbé pers. comm. 2015).

Previously published Red List assessments:

Geographic Range [top]

Range Description:

Pan troglodytes ellioti (Matschie, 1914) ranges from Cameroon, west of the Sanaga River, to Nigeria. Historically, chimpanzees were probably widespread in southern Nigeria, but west of the Cross River their range is now highly fragmented, restricted to a few isolated forest areas in southwestern Nigeria, and the floodplain and delta of the River Niger.

Countries occurrence:
Cameroon; Nigeria
Additional data:
Upper elevation limit (metres):2000
Range Map:Click here to open the map viewer and explore range.

Population [top]


Pan t. ellioti is the least numerous subspecies of Chimpanzee with a total population that is almost certainly less than 9,000 individuals and probably less than 6,000 individuals remaining (Morgan et al. 2011, J. Oates pers. comm. 2015). One of the largest, and probably most secure, subpopulations of P. t. ellioti is in Gashaka-Gumti National Park in Nigeria, which has an estimated subpopulation of 900–1,000 (Ogunjemite et al. 2010, Adanu et al. 2011). Other major subpopulations are found in Cameroon in Banyang-Mbo Wildlife Sanctuary (estimated at 500–900 or 800–1,450 individuals, depending on nest-decay parameters used; Greengrass and Maisels 2007), in the proposed Ebo National Park (estimated at 626–1,480 individuals, M. Ndimbe and B. Morgan pers. comm. 2015), and in Mbam and Djerem National Park (at least 500 individuals, Maisels et al. 2009).

Pan t. ellioti has been the focus of intensive, non-invasive sample collection efforts for genetic studies throughout much of its geographic range in Cameroon; this sampling has found that many Chimpanzees still survive outside protected areas, particularly in the mountainous regions along the Nigeria-Cameroon border and south of the Adamawa Plateau in central Cameroon (M.K. Gonder and M. Mitchell, pers. comm. 2015). From these genetic studies the current effective population size of P. t. ellioti in Cameroon is estimated at 3,000–4,500 individuals (Mitchell et al. 2015).

Current Population Trend:Decreasing
Additional data:
Continuing decline of mature individuals:Yes
Extreme fluctuations:NoPopulation severely fragmented:Yes
Continuing decline in subpopulations:Unknown
Extreme fluctuations in subpopulations:UnknownAll individuals in one subpopulation:No

Habitat and Ecology [top]

Habitat and Ecology:

The Nigeria-Cameroon Chimpanzee occurs in primary and secondary moist lowland forest, montane and submontane forest, dry forest, forest galleries in savanna woodland, and farmland (Oates 2011, Sesink Clee et al. 2015, O. Doumbé pers. comm. 2015).

Like other Chimpanzees, P. t. ellioti is omnivorous. Fruits (especially figs) comprise about half the diet, but leaves, bark, stems and animals are also eaten (Dutton and Chapman 2015). Tools made from plant parts are used to extract bees, ants and termites from their nests (Fowler and Sommer 2007), stone hammers are used to crack nuts (Morgan and Abwe 2006), and monkeys and other mammals are probably captured for food (Morgan et al. 2012).

Chimpanzees live in social communities. One community in Gashaka-Gumti National Park, Nigeria, was known to contain at least 35 individuals and range over at least 26 km² (Sommer et al. 2004). Another community of not more than 8 individuals in the Babanki-Finge forest, Cameroon, ranges over about 35 km² (O. Doumbé pers. comm. 2015).

Generation Length (years):25
Movement patterns:Not a Migrant

Use and Trade [top]

Use and Trade:

Great apes are completely protected by national and international laws in all countries of their range, and it is, therefore, illegal to kill, capture or trade in live Chimpanzees or their body parts.

Threats [top]

Major Threat(s):

Based on the Regional Action Plan for the Conservation of the Nigeria-Cameroon Chimpanzee (Morgan et al. 2011): The two main threats to the survival of Nigeria-Cameroon Chimpanzees are poaching and habitat loss. These threats are exacerbated by the expansion of human populations within P. t. ellioti’s range and economic growth in Cameroon and Nigeria. According to the United Nations, Cameroon’s population increased almost four-fold between 1950 and 2010 (from 4.5 to 20.6 million) and Nigeria’s population increased almost five-fold (from 37.9 to 159.4 million) in the same period. During the next 20 years to 2035, the human populations of these countries are expected to reach nearly 37 million and 294 million, respectively (UN 2015).

1. Poaching

As the human population has grown steadily in both Cameroon and Nigeria, the ease of obtaining arms, more efficient transport systems, and higher financial incentives for supplying urban markets with bushmeat and other forest commodities have led to a ‘bushmeat crisis’, whereby swathes of land have been cleared of wildlife and often also their forest cover. Illegal hunting of Chimpanzees to supply the bushmeat trade and, to a lesser extent, to provide body parts for traditional medicine, is almost certainly the greatest threat to the survival of most P. t. ellioti populations. Although most Chimpanzees are hunted with guns, they are also caught in snares set for terrestrial animals. Several lines of evidence point to the devastating impact of hunting. For example, there are large areas of suitable Chimpanzee habitat in the Okwangwo division of the Cross River National Park and the adjacent Takamanda National Park where Chimpanzees are encountered at low frequencies, and which suffer from high hunting pressure (Mboh and Warren 2007, Imong and Warren 2008); during a six-month study of rural markets in southeastern Nigeria and southwestern Cameroon in 2002–2003, Fa et al. (2006) recorded 240 Chimpanzee carcasses; in a five-week period in 2009, a Wildlife Conservation Society survey of eight markets in the transboundary region of Cross River State, Nigeria, counted six Chimpanzee carcasses. Many of the carcasses found in eastern Nigerian markets probably derive from Cameroon, but are traded in Nigeria where bushmeat fetches higher prices. Given the limited number of Chimpanzees persisting in many areas and their slow reproductive rate, this hunting pressure is not sustainable.

2. Habitat Loss

Forests in the P. t. ellioti range continue to be lost, degraded and fragmented by agriculture, logging, grazing and fire. In Nigeria, several forest reserves have been converted to farmland and to commercial oil-palm and rubber plantations, while large areas of forest surrounding key protected areas such as Okomu and Cross River national parks have already been converted to oil-palm plantations. In Cameroon, extensive new oil-palm developments are underway in both Littoral and South West regions, and new logging concessions continue to be established. Logging companies can quickly clear and upgrade existing seasonal roads to support the evacuation of timber year round, and this road access opens up the forest to more intense hunting pressure (Wilkie et al. 2000, Laurance et al. 2006). Noise and disturbance can cause Chimpanzees to move into areas occupied by other Chimpanzee communities, where they face aggression that can lead to fatalities (White and Tutin 2001). Logging, especially in southwestern Nigeria, is often been followed by farming and further conversion of Chimpanzee habitat. In the drier parts of this Chimpanzee’s range (such as Mbam & Djerem and the Bamenda Highlands in Cameroon, and Gashaka-Gumti and Mambilla in Nigeria) pastoralists have encouraged the destruction of forest with fires to provide more grazing for their cattle, which may subsequently be converted to farmland.

3. Disease

Although the Ebola virus outbreaks that have decimated some African ape populations have not been recorded in the range of P. t. ellioti, infectious disease is a potential threat to the future of these Chimpanzees. Emerging diseases are a threat to Chimpanzees in neighbouring West African countries (e.g., Boesch 2008) and even the fragmented nature of the Nigeria-Cameroon Chimpanzee populations may not provide a barrier to limit the spread of disease among them.

4. Population Fragmentation

The combined impacts of habitat loss and poaching have been gradually fragmenting P. t. ellioti populations, so that many of those remaining are small and isolated; they are therefore at increased risk of extinction from disease and other unpredictable events.

5. Climate Change

There are two genetic populations of P. t. ellioti - one located in the forested regions of western Cameroon and eastern Nigeria and a second population in the savanna-woodland mosaic habitats of central Cameroon. The habitat of this second population is projected to decline under all future climate change scenarios, with a significant population decline predicted as early as 2020 (Sesink Clee et al. 2015).

Conservation Actions [top]

Conservation Actions:

From the Regional Action Plan for the Conservation of the Nigeria-Cameroon Chimpanzee (Morgan et al. 2011): Historically, the conservation of Nigeria-Cameroon Chimpanzees has been approached through the creation of protected areas with clearly defined, legislated and enforced levels of permitted exploitation, but these protected areas generally received inadequate resources for their effective management. Recently, however, the process of creating and effectively protecting national parks and reserves has been reinvigorated, particularly in Cameroon, and there are currently nine national parks and two wildlife sanctuaries in the range of P. t. ellioti. Such areas may offer the only hope of sustaining populations given the burgeoning needs of the human population. Nonetheless, many Chimpanzees exist outside protected areas, and there has been a rise in the application of community-based conservation measures across the region, which might also be of benefit.

In addition to the general approaches described below, numerous regional or site-specific conservation actions have been prioritised for P. t. ellioti, as detailed in the action plan (Morgan et al. 2011). For example, a ‘Southwestern Nigeria Chimpanzee Conservation Planning Unit’ recommended that forest conversion around Okumu National Park should be ceased and the land incorporated into the park, and that a research station should be established. In Cameroon, actions recommended for Korup National Park included re-tracing the park and enclave boundaries, and rehabilitating the tourism infrastructure.

Increasing Institutional and Human Capacity

Developing the capacity of national conservation managers, researchers and government officials against a background of widespread corruption in Cameroon and Nigeria poses enormous challenges. Nevertheless, amplified investment in national conservation leaders is an important and currently underfunded activity. Enhancing local capacity should be a cornerstone of all conservation NGO work, whether it be through supporting further education opportunities, or establishing or contributing to improving existing centres of further education. At a local scale, initiatives such as encouraging community participation in local conservation projects has often been incidental—providing casual employment, or triggering a market for village commodities such as locally-produced food, for example. There are increasing cases, however, of communities taking a more active role in preserving the forests over which they might previously have had traditional access rights. One example is in the Mbe Mountains, Nigeria, where nine communities were assisted to form a conservation association. Through this association, these communities are now actively involved in the management and conservation of the area and levels of hunting have declined. Nonetheless, the association relies on an international NGO for funding and protection of the mountain and its wildlife. 

Education Outreach Programmes

Instigating outreach programmes to communities living in close proximity to Chimpanzees and other flagship species is often high on the agenda of conservation NGOs. This results from the assumption that long-term change can best be achieved through accelerating change in societal attitudes towards wildlife. Whilst incontrovertible examples of such programmes leading to a decrease in wildlife exploitation have yet to be demonstrated from this region, studies from elsewhere point to the value of such projects (Jacobson 2010). Better coordination of such programmes would benefit several small field projects, where the people involved may not have the time, resources or experience to instigate their own outreach activities. Increasing public awareness of the benefits and values of wildlife conservation is becoming easier to achieve as Cameroon and Nigeria, together with the rest of the world, become more connected to the global community. The use of media such as radios, that are common even in remote villages, as well as the increasingly ubiquitous televisions and smart phones allow for new opportunities in conveying information on both local and national scales.

Citation: Oates, J.F., Doumbe, O., Dunn, A., Gonder, M.K., Ikemeh, R., Imong, I., Morgan, B.J., Ogunjemite, B. & Sommer, V. 2016. Pan troglodytes ssp. ellioti. The IUCN Red List of Threatened Species 2016: e.T40014A17990330. . Downloaded on 15 August 2018.
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