Sierra Leone Nationwide
Summary
- Western chimpanzees (Pan troglodytes verus) are present in Sierra Leone.
- It has been estimated that 5,580 (CI: 3,052–10,446) individuals occur in Sierra Leone.
- The chimpanzee population trend is decreasing.
- Sierra Leone has a total surface area of 72,500 km².
- Key threats to chimpanzees are hunting, logging, and mining.
- Conservation activities focus on law enforcement, habitat protection, and environmental education and awareness raising.
Site characteristics
Located in West Africa, Sierra Leone lies entirely within the geographic range of western chimpanzees. Sierra Leone’s vegetation is characterized by two major biogeographic ecosystems: the Sudan-Guinea savanna biome mainly in the north and the Guinea-Congo forest biome mainly in the south-east of the country (EPASL 2017).The country contains blocks of Upper Guinea forests, which are among the most biologically diverse ecosystems in the world (Brncic et al. 2010, Myers et al. 2000). However, closed forest vegetation is greatly declining and accounts for only 3-5% of the land cover (EPASL 2017). Large mammals found in the country include elephant (Loxodonta africana), pygmy hippopotamus (Hexaprotodon liberiensis), leopard (Panthera pardus), bongo (Tragelaphus eurycerus), caracal (Caracal caracal), and several duiker and primate species (Brncic et al. 2010). In addition, the country is known to have 632 regularly occurring birds, of which 14 species are endemic to the Upper Guinea Forest ecosystem (Okoni-Williams et al. 2014).
Table 1: Basic site information for Sierra Leone
| Area | 72,500 km² |
| Coordinates | 8.72 N, -11.73 W |
| Designation | Not applicable |
| Habitat types | Subtropical/tropical moist lowland forest, Subtropical/tropical moist montane forest, Subtropical/tropical dry lowland forest, Savanna, Plantations, Rural gardens, Urban areas, Subtropical/tropical heavily degraded former forest |
IUCN habitat categories Site designations
Ape status
In 1979, Teleki and Baldwin conducted the first nationwide survey, from which they estimated a total population of 1,500 to 2,500 chimpanzees (Brncic et al. 2010). However, the survey was not quantitative nor systematic; therefore, the estimated abundance was likely an underestimate (Brncic et al. 2010). Between 2009 and 2010, a systematic nationwide survey covering 386 km was conducted (Brncic et al. 2010). This survey filled an important gap on the status of chimpanzees in Sierra Leone, and it was concluded that the country holds one of the largest populations remaining in West Africa (Brncic et al. 2010). Based on interview data and records of chimpanzee captures, the population is significantly smaller than 60 years ago (Brncic et al. 2010).
Table 2: Great ape population estimates in Sierra Leone
| Species | Year | Abundance estimate (95% confidence interval) | Density estimate (per km²) | Encounter rate (nests/km) | Area | Method | Source | Comments | A.P.E.S. database ID |
|---|---|---|---|---|---|---|---|---|---|
| Pan troglodytes verus | 1979-1980 | 1,500-2,500 | Nationwide | Interview method, index survey, and informed guess | Telekin & Baldwin 1981, as cited by Brncic et al. 2010 | The survey covered 9,000 km by car, and 1,200 km by foot. | |||
| Pan troglodytes verus | 2009-2010 | 5,580 (3,052-10,446) | Nationwide | Line transects (Distance) | Brncic et al. 2010 | Survey effort: 386 km | |||
| Pan troglodytes verus | 2015 | 5,925 (1,951-12,668) | Nationwide | Model estimate | Heinicke et al. 2019 | Based on density distribution predicted for geographic range of western chimpanzees using models and transect survey data |
Threats
In the 1970s and early 1980s, the export of chimpanzees for biomedical research and the entertainment industry was a major threat in Sierra Leone (Brncic et al. 2010). In fact, between 1957 and 1979, it was estimated that 2,574 live chimpanzees were traded (Robinson 1971). After banning the killing and live trade of chimpanzees in 1985, the pet trade persisted due to weak law enforcement, and only began to significantly decrease in the 1990s with the establishment of Tacugama Chimpanzee Sanctuary (Brncic et al. 2010). More recently, key threats to chimpanzees are hunting and habitat loss (Brncic et al. 2010). Chimpanzees are hunted for their meat, but may also be killed as a defense against crop raiding (Brncic et al. 2010). Drivers of habitat loss in Sierra Leone include legal and illegal logging (sometimes linked to fuelwood consumption), agriculture (mostly small-scale, slash-and-burn agriculture), uncontrolled bush fires for clearing land, and mining (Brncic et al. 2010, EPASL 2017).
Conservation activities
Conservation activities in Sierra Leone focus mainly on environmental education, raising conservation awareness, habitat protection, and law enforcement to reduce poaching pressure (BirdLife International 2019, Tacugama Chimpanzee Sanctuary 2019). The Ministry of Agriculture, Forestry and Food Security (MAFFS) is responsible for the management of protected areas and biodiversity conservation in Sierra Leone (Brncic et al. 2010, Okoni-Williams et al. 2001). The Wildlife Conservation Act of 1972 forms the backbone of conservation legislation, and recognizes several categories of protected areas (Okoni-Williams et al. 2001). NGOs involved in the implementation of conservation activities include the Conservation Society of Sierra Leone (CSSL), the Royal Society for the Protection of Birds (RSPB), and Tacugama Chimpanzee Sanctuary.
Impediments
Table 5: Impediments reported for Sierra Leone
| Impediment | Source |
|---|---|
| Lack of human resources | Okoni-Williams et al. 2001 |
| Lack of law enforcement | Okoni-Williams et al. 2001 |
Research activities
Several surveys have been done at the site-level to monitor wildlife and estimate chimpanzee abundances (e.g., Brncic et al. 2010, Klop et al. 2008, Davies et al. 2008). Ecological research across the country began in the early 1980s, with Teleki and Baldwin conducting a nationwide survey (Brncic et al. 2010). Since 2012, the Tacugama Community Outreach Programme has been conducting research using camera traps and interviewing people across the country.
Documented behaviours
Table 6: Great ape behaviors reported for Sierra Leone
| Behavior | Source |
|---|---|
| Stepping sticks | Alp 1997 |
| Seat sticks | Alp 1997 |
| Nut cracking | Whitesides 1985 |
Relevant datasets
References
Alp, R. (1997). "Stepping-sticks" and "seat-sticks": new types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone. American Journal of Primatology, 41(1):45-52.
Brncic, T.M., Amarasekaran,B. & McKenna,A. (2010). Final Report of the Sierra Leone National Chimpanzee Census Project. Tacugama Chimpanzee Sanctuary, Freetown, Sierra Leone.
Davies, Glyn & Schulte-Herbruggen, Bjorn & Kümpel, Noëlle & Mendelson, Samantha. (2008). Hunting and Trapping in Gola Forests, South-Eastern Sierra Leone: Bushmeat from Farm, Fallow and Forest. 10.1002/9780470692592.ch1.
Environmental Protection Agency- Sierra Leone (EPASL) (2017). Sierra Leone’s Second National Biodiversity Strategy and Action Plan 2017-2026.
Heinicke et al. 2019. Advancing conservation planning for western chimpanzees using IUCN SSC A.P.E.S. – the case of a taxon-specific database. Environmental Research Letters, https://doi.org/10.1088/1748-9326/ab1379
Klop, E., Lindsell, J.A. & Siaka, A. (2008) Biodiversity of Gola Forest, Sierra Leone. Unpublished Report. Royal Society for the Protection of Birds, Sandy, UK, and Conservation Society of Sierra Leone, Freetown, Sierra Leone.
Okoni-Williams, A.D., Thompson, H.S., Wood, P., Koroma, A.P., & Robertson, P. (2001). Sierra Leone. Important Bird Areas in Africa and associated islands: Priority sites for conservation. Pisces Publications and BirdLife International, Newbury and Cambridge, UK.
Okoni-Williams, A.D., Thompson H.S. & Monde, S. (2014). State of Sierra Leone’s Birds: A Guide for Policy and Conservation Action. Conservation Society of Sierra Leone and BirdLife International, 2014.
Robinson, P.T. (1971). Wildlife trends in Liberia and Sierra Leone. Oryx, 11:117-122.
Tacugama Chimpanzee Sanctuary (2019). Online: https://www.tacugama.com/about-us/
Whitesides, G.H. (1985) Nut cracking by wild chimpanzees in Sierra Leone, West Africa. Primates 26: 91. https://doi.org/10.1007/BF02389050
Page completed by: A.P.E.S. Wiki Team Date: 13/11/2019