Bulindi

East Africa > Uganda > Bulindi

Summary

Male chimpanzees crossing the road in Bulindi (Photo by Jacqueline Rohen)

• Eastern chimpanzees (Pan troglodytes schweinfurthii) are present in Bulindi.
• It is estimated that 22 individuals inhabit the site.
• The chimpanzee population trend is decreasing.
• The site has a total size of 25 km².
• Key threats to chimpanzees are habitat loss, human-chimpanzee conflict, lethal crop protection measures, roads, and diseases.
• Conservations activities implemented by the Bulindi Chimpanzee and Community Project focus on supporting local residents through livelihood alternatives to deforestation, extensive tree planting, investing in children’s education, local community outreach, and provision of boreholes and energy stoves.

Site characteristics

Landscape view of Bulindi showing main road and riparian forest at center (Photo by Ronan Donovan)

Bulindi (1°29′N, 31°28′E) is situated midway between the Budongo and Bugoma Central Forest Reserves in western Uganda, within the so-called Budongo-Bugoma corridor. Bulindi is unique in that it is a long-term chimpanzee research site located entirely on land belonging to local villagers (McLennan et al. 2020). The site is predominantly agricultural and village land, with remnant patches of unprotected and highly degraded riparian and swamp forest (McLennan & Plumptre 2012). The field site corresponds to the home range of one community of eastern chimpanzees. Other primate species found at the site include black and white colobus monkeys (Colobus guereza), tantalus monkeys (Chlorocebus tantalus), and blue monkeys (Cercopithecus mitis); olive baboons (Papio anubis) are transitory visitors.

Table 1. Basic site information for Bulindi

Area	25 km²
Coordinates	1.483333 , 31.466667
Designation	Unclassified
Habitat types	Riparian forest, papyrus swamp, rural gardens, arable land, plantations, village and urban areas, subtropical/tropical heavily degraded former forest

IUCN habitat categories Site designations

Ape status

Community size declined since the first period of research in 2006-2008, when an estimated 30 individuals or more were present (McLennan & Hill 2010): between 2012 (when all individuals were identified) and 2020 community size has numbered 18-22 individuals. The marked decline in community size between 2008 and 2012 is at least partially attributable to trappings (McLennan et al. 2012).

Table 2. Ape population estimates in Bulindi

Species	Year	Abundance estimate (95% CI)	Density estimate [ind./ km²] (95% CI)	Encounter rate (nests/km)	Area	Method	Source	Comments	A.P.E.S. database ID
Pan troglodytes schweinfurthii	2020	22	Approx. 1 individual/km²​ within the home range		Bulindi	Full count	BCCP 2020	Community size has varied between 18-22 individuals (2012-2020)

Threats

More than 80% of the natural forest at Bulindi was converted to farmland in less than 10 years (McLennan et al. 2020). Rapid habitat loss and human encroachment has led to increased conflict between villagers and the resident chimpanzees; loss of wild foods has caused chimpanzees to forage daily for agricultural foods in croplands and around homes (McLennan 2013; McLennan et al. 2020). The chimpanzees are highly threatened by anthropogenic factors including ongoing habitat conversion, lethal crop protection measures (e.g. steel 'mantraps'; McLennan et al. 2012; Cibot et al. 2019a), a busy main road that divides their home range (McLennan & Asiimwe 2016), exposure to novel pathogens (McLennan et al. 2017, 2018) and anthropogenic stressors (McLennan et al. 2019a), and habitat loss reducing opportunities for female dispersal (McCarthy et al. 2020).

Table 3. Threats to apes in Bulindi

Category	Specific threats	Threat level	Quantified severity	Description	Year of threat
1. Residential & commercial development		Absent
2. Agriculture & aquaculture	2.1 Annual & perennial non-timber crops	High	Between 2006 and 2014, 80% of forest in the chimpanzees' home range was cleared entirely for farming (McLennan et al. 2020).	Agricultural expansion for both subsistence crops and cash crops such as sugarcane, tobacco, maize and rice (McLennan & Plumptre 2012; McLennan & Hill 2015).	Ongoing (2020)
3. Energy production & mining		Absent
4. Transportation & service corridors	4.1 Roads & railroads	High	1 adult female chimpanzee, and her infant, were killed crossing the road during 2015-2020 (McLennan & Asiimwe 2016).	A busy main road connecting Hoima and Masindi towns crosses the chimpanzee range. In 2017-28 the road was widened and tarmacked. The chimpanzees cross this road at times on a daily basis, putting them at risk of collision with vehicles (McLennan & Asiimwe 2016).	Ongoing (2020)
5. Biological resource use	5.3 Logging & wood harvesting	High	Most large trees were logged for timber between c. 2000-2015 (McLennan, unpubl. data).	Unregulated commercial logging, i.e. local landowners sell trees to timber dealers, and then clear the land for farming (McLennan & Plumptre 2012). Residents also cut small trees for firewood.	Ongoing (2020)
6. Human intrusion & disturbance	6.3 Work & other activities	High		Chimpanzees in Bulindi share their landscape with a high-density human population. The chimpanzees encounter people working in gardens and agricultural fields, or engaged in other work activities (e.g. house building, carpentry, cattle herding), on a daily basis.	Ongoing (2020)
7. Natural system modifications	7.1 Fire & fire suppression	Medium		Fires used for clearing agricultural gardens threaten remaining forest areas during dry seasons.	Ongoing (2020)
7. Natural system modifications	7.3 Other ecosystem modifications	High	Only 1 female migrated into the Bulindi community during 2012-2020.	Reduced options for female dispersal caused by clearance of riparian forest corridors (McCarthy et al. 2020).	Ongoing (2020)
8. Invasive & other problematic species, genes, diseases		High	Prevalence (% of chimpanzees positive) for enterobacterial pathogens Salmonella spp., EHEC, and Shigella spp./EIEC was 7%, 20% and 20%, respectively, in 2015 (McLennan et al. 2018). Prevalence (% positive fecal samples) for potentially pathogenic nematodes was 58%, 48% and 44% for Strongyloides sp.,Oesophagostomum spp.,and Necator sp., respectively, in 2012-13 (McLennan et al. 2017).	Chimpanzees in Bulindi have contact with waste of domestic animals and people. A number of potentially pathogenic intestinal parasites that may result from cross-species transmission have been detected in chimpanzees at Bulindi including enterobacteria such as Salmonella spp., enterohemorrhagic Escherichia coli (E. coli) and Shigella spp./enteroinvasive E. coli (McLennan et al. 2018), among various nematode and protozoan parasites (Ota et al. 2015; McLennan et al. 2017). Respiratory diseases are also a threat (McLennan, unpubl. data). The chimpanzees exhibit an unusually high frequency of self-medication (whole leaf swallowing; McLennan & Huffman 2012; McLennan et al. 2017).	Ongoing (2020)
9. Pollution	9.3 Agricultural & forestry effluents	High		Local farmers commonly use inorganic herbicides and pesticides; potential impacts on the chimpanzees are not yet known.	Ongoing (2020)
10. Geological Events		Absent
11. Climate change & severe weather		Absent
12. Other options	12.1 Other threat	High	At least 5 chimpanzees caught in steel traps, 2007-2011 (McLennan et al. 2012).	The chimpanzees are at high risk of potentially lethal crop protection measures, particularly large steel leg-hold traps (known as 'mantraps'). Mantraps are placed by agricultural fields by a minority of farmers to deter crop-foraging wildlife including wild pigs, monkeys and the chimpanzees (McLennan et al. 2012; Cibot et al. 2019a).	Ongoing (2020)
12. Other options	12.1 Other threat	High	Chimpanzee fecal glucocorticoid metabolite concentrations were substantially higher in chimpanzees in Bulindi compared to conspecifics in minimally-disturbed habitat in nearby Budongo Forest (McLennan et al. 2019a).	High exposure to anthropogenic stressors including hostile interactions with local humans, roads, dogs, anthropogenic noise (McLennan et al. 2019a).	Ongoing (2020)

IUCN Threats list

Conservation activities

The Bulindi Chimpanzee and Community Project (BCCP) was initiated in 2015 to help conserve the chimpanzees in Bulindi and their habitat, and provide livelihood support to local households. The project has since expanded to other regions within the Budongo-Bugoma corridor where chimpanzees survive in unprotected habitat around villages. Main project activities include supporting local residents through livelihood alternatives to deforestation, extensive tree planting, investing in children’s education, local community outreach, and provision of boreholes and energy stoves. These activities help reduce reliance on remaining natural forest and increase tolerance towards chimpanzees. In parallel, BCCP conducts long-term research and monitoring of multiple groups of 'village chimpanzees' (including the Bulindi community) to understand behavioral adaptations to human-driven environmental change, to aid targeted conservation efforts, and mitigate threats to the chimpanzees' welfare and survival (BCCP 2020).

Table 4. Conservation activities in Bulindi

Category	Specific activity	Description	Year of activity
1. Residential & commercial development	Not reported
2. Agriculture & aquaculture	2.11. Farm more intensively and effectively in selected areas and spare more natural land	BCCP has a coffee growing alternative livelihood project. The project provides coffee seedlings to farmers and guidance on 'best practice' coffee farming. Unlike other cash crops (e.g. tobacco and rice), coffee is 'chimpanzee friendly' because farmers establish coffee in existing gardens rather than cutting new gardens in forest or wetlands, and chimpanzees and other primates do not eat any part of the coffee plant. Coffee matures after 2-3 years and the harvest can contribute significantly to household incomes (BCCP 2020).	Ongoing (2020)
3. Energy production & mining	Not reported
4. Transportation & service corridors	Not reported
5. Biological resource use	5.17. Provide sustainable alternative livelihoods; establish fish- or domestic meat farms	BCCP has an extensive tree planting program in Bulindi since 2015, including raising indigenous tree species for habitat enrichment, coffee as an alternative livelihood, and fast-growing timber species for sustainable household woodlots. The woodlots provide local households with an alternative source of wood and alternative income from timber sales, reducing reliance on remaining natural forest (BCCP 2020).	Ongoing (2020)
6. Human intrusion & disturbance	Not reported
7. Natural system modifications	Not reported
8. Invasive & other problematic species, genes, diseases	8.7. Wear face-masks to avoid transmission of viral and bacterial diseases to primates	Strict use of face masks and hand sanitisers by researchers and local 'Chimpanzee Monitors' entering forest areas, and when in proximity to chimpanzees; bespoke health and hygiene training provided to all staff (BCCP, unpublished data).	Ongoing (2020)
9. Pollution	Not reported
10. Education & Awareness	10.1. Educate local communities about primates and sustainable use	BCCP provides conservation outreach for primary schoolchildren. The program aims to foster interest, empathy, and understanding of chimpanzees, interest in tree planting and awareness of importance of natural forest, and promotes 'safe' behavior for children encountering chimpanzees (BCCP 2020).	Ongoing (2020)
11. Habitat Protection	11.8. Plant indigenous trees to re-establish natural tree communities in clear-cut areas	BCCP has an extensive tree planting program in Bulindi, including raising indigenous tree species for habitat enrichment and restoration since 2015 (BCCP 2020).	Ongoing (2020)
12. Species Management	Not reported
13. Livelihood; Economic & Other Incentives	13.1. Provide monetary benefits to local communities for sustainably managing their forest and its wildlife (e.g. REDD, employment)	BCCP supports local households that own areas of natural forest used by the chimpanzees by sponsoring their children's education. Since inception in 2015, this school child sponsorship scheme has been instrumental in conserving remaining patches of riparian forest, following 2 decades of forest clearance in Bulindi (BCCP 2020).	Ongoing (2020)
13. Livelihood; Economic & Other Incentives	13.2. Provide non-monetary benefits to local communities for sustainably managing their forest and its wildlife (e.g. better education, infrastructure development)	The Bulindi Chimpanzee & Community Project (BCCP) was initiated in 2015 to help conserve the chimpanzees in Bulindi and their habitat, and provide livelihood support to local households. The project has since expanded to other regions in the Budongo-Bugoma corridor where chimpanzees survive in unprotected habitat around villages. Project activities include supporting local residents through livelihood alternatives to deforestation, extensive tree planting, investing in children’s education, and provision of boreholes and energy stoves, helping reduce reliance on remaining natural forest and increase tolerance of chimpanzees. In parallel, BCCP conducts long-term research and monitoring of the chimpanzees to understand adaptations to human-driven environmental change and mitigate threats to their welfare and survival (BCCP 2020).	Ongoing (2020)
13. Livelihood; Economic & Other Incentives	13.2. Provide non-monetary benefits to local communities for sustainably managing their forest and its wildlife (e.g. better education, infrastructure development)	In partnership with water charities (BridgIT, Drop4Drop and Suubi Community Projects–Uganda), BCCP constructs village boreholes (water wells) for local communities to improve health and quality of life by providing residents in chimpanzee areas with access to clean, safe water away from the forest. The wells reduce negative encounters between chimpanzees and people (often children) collecting water at forest streams. BCCP also constructs energy-saving stoves for residents, helping reduce household fuel consumption, alleviating pressure on chimpanzee habitat, while providing households with safer, more efficient cook stoves.	Ongoing (2020)

Conservation activities list (Junker et al. 2017)

Challenges

Two adult males sharing a cultivated jackfruit at Bulindi (Photo by Jacqueline Rohen)

Ongoing habitat conversion (clearance of riparian forest for agriculture) (McLennan & Plumptre 2012; McLennan & Hill 2015; McLennan et al. 2020). High levels of human-chimpanzee interactions including habitual feeding on agricultural crops by chimpanzees, frequent harassment of chimpanzees by local residents, occasional chimpanzee aggression towards humans, especially children (McLennan 2008; McLennan & Hill 2012, 2013). Human-human conflicts, i.e. differences between groups or individuals (e.g. local residents and conservation practitioners) about the management and conservation of chimpanzees; politicization of chimpanzees by local politicians (McLennan & Hill 2013).

Table 5. Challenges reported for Bulindi

Challenge	Source
Lack of financial means	McLennan pers. comm.
Lack of national protection	McLennan 2008
Lack of law enforcement	McLennan 2008

Research activities

Chimpanzees in Bulindi were first studied in 2006-2008. Research resumed in 2012 and continues to the present; since 2015 the chimpanzees are habituated. Research topics include: (1) chimpanzees dietary and behavioral responses to habitat loss, agricultural expansion and increased contact with humans, including crop feeding and human-chimpanzee interactions (e.g. McLennan & Hill 2010; McLennan 2013; McLennan & Hockings 2014; McLennan et al. 2019a, 2020); (2) attitudes towards chimpanzees among local residents and constraints to coexistence (e.g. McLennan & Hill 2012, 2013); (3) threats to chimpanzee survival (e.g. McLennan et al. 2012; McLennan & Asiimwe 2016; Cibot et al. 2019a); (4) health and disease (e.g. McLennan et al. 2017, 2018); (5) tool use (McLennan 2011a; McLennan et al. 2019b); and (6) paternity and reproductive success (Cibot et al. 2019b; McCarthy et al. 2020).

Members of the Bulindi chimp community resting in gardens (Photo by Matthew McLennan)

Documented behaviours

Table 6. Ape behaviors reported for Bulindi

Behavior	Source
Crop feeding	McLennan 2013; McLennan et al. 2020
Road crossing	McLennan & Asiimwe 2016
Food sharing (agricultural crops)	McLennan et al. 2020
Hunting animals without consumption	Cibot et al. 2017
Self medication (leaf swallowing)	McLennan & Huffman 2012; McLennan et al. 2017
Infant carrying by male chimpanzees	Cibot et al. 2019b
Honey digging with stick tools	McLennan 2011a; McLennan et al. 2019b
Hand-clasp grooming	McLennan 2011b
High male reproductive skew	McCarthy et al. 2020
Chimpanzee-villager interactions (including human directed aggression)	McLennan & Hill 2010; McLennan 2010
Tool-assisted extractive foraging	McLennan et al. 2019b
Foraging adaptations to forest loss	McLennan et al. 2020
Nest tying	McLennan 2018

External links

Bulindi Chimpanzee & Community Project website
Bulindi Chimpanzees Facebook
Bulindi Chimpanzees Instagram
Bulindi National Geographic

Relevant datasets

A.P.E.S Portal

References

BCCP. (2020). 2019 Annual Report to Friends & Funders. Bulindi Chimpanzee and Community Project, Hoima, Uganda.
Cibot, M., Sabiiti, T., and McLennan, M.R. (2017). Two cases of chimpanzees interacting with dead animals without food consumption at Bulindi, Hoima District, Uganda. Pan Africa News, 24(1), 6–8. https://doi.org/10.5134/226632
Cibot, M., Le Roux, S., Rohen, J., & McLennan, M.R. (2019a). Death of a trapped chimpanzee: survival and conservation of great apes in unprotected agricultural areas of Uganda. African Primates, 13, 47–56.
Cibot, M., McCarthy, M. S., Lester, J. D., Vigilant, L., Sabiiti, T., & McLennan, M. R. (2019b). Infant carrying by a wild chimpanzee father at Bulindi, Uganda. Primates, 60(4), 333-338. https://doi.org/10.1007/s10329-019-00726-z
McCarthy, M.S., Lester, J.D., Cibot, M., Vigilant, L., & McLennan, M.R. (2020). Atypically high reproductive skew in a small wild chimpanzee community in a human-dominated landscape. Folia Primatologica, 91(6), 688–696. https://doi.org/10.1159/000508609
McLennan, M.R. (2008). Beleaguered chimpanzees in the agricultural district of Hoima, western Uganda. Primate Conservation, 23, 45–54. https://doi.org/10.1896/052.023.0105
McLennan, M.R. (2010). Case study of an unusual human–chimpanzee conflict at Bulindi, Uganda. Pan Africa News, 17(1), 1–4.
McLennan, M.R., & Hill, C.M. (2010). Chimpanzee responses to researchers in a disturbed forest–farm mosaic at Bulindi, western Uganda. American Journal of Primatology, 72, 907–908. https://doi.org/10.1002/ajp.20839
McLennan, M. R. (2011a). Tool-use to obtain honey by chimpanzees at Bulindi: New record from Uganda. Primates, 52(4), 315-322. https://doi.org/10.1007/s10329-011-0254-6
McLennan, M. R. (2011b). Preliminary observations of hand-clasp grooming by chimpanzees at Bulindi, Uganda. Pan Africa News, 18(2), 18–20.
McLennan, M. R. & Plumptre, A. J. (2012). Protected apes, unprotected forest: composition, structure and diversity of riverine forest fragments and their conservation value in Uganda. Tropical Conservation Science Vol. 5(1):79-103. https://doi.org/10.1177%2F194008291200500108
McLennan, M. R., Hyeroba, D., Asiimwe, C., Reynolds, V., & Wallis, J. (2012). Chimpanzees in mantraps: Lethal crop protection and conservation in Uganda. Oryx, 46(4), 598-603. https://doi.org/10.1017/S0030605312000592
McLennan, M. R. & Huffman, M. (2012). High Frequency of Leaf Swallowing and Its Relationship to Intestinal Parasite Expulsion in “Village” Chimpanzees at Bulindi, Uganda. American Journal of Primatology, 74, 642–650. https://doi.org/10.1002/ajp.22017
McLennan, M.R. & Hill, C.M. (2012). Troublesome neighbours: Changing attitudes towards chimpanzees (Pan troglodytes) in a human-dominated landscape in Uganda. Journal for Nature Conservation, 20(4), 219–227. https://doi.org/10.1016/j.jnc.2012.03.002
McLennan, M.R. and Hill, C.M. (2013). Ethical issues in the study and conservation of an African great ape in an unprotected, human-dominated landscape in western Uganda. In: Ethics in the Field: Contemporary Challenges, ed. J. MacClancy and A. Fuentes. Oxford: Berghahn, pp. 42–66.
McLennan, M.R. (2013). Diet and feeding ecology of chimpanzees (Pan troglodytes) in Bulindi, Uganda: foraging strategies at the forest–farm interface. International Journal of Primatology, 34(3), 585–614. https://doi.org/10.1007/s10764-013-9683-y
McLennan, M.R., Hockings, K.J. (2014). Wild chimpanzees show group differences in selection of agricultural crops. Scientific Reports, 4, 5956. https://doi.org/10.1038/srep05956
McLennan, M.R. & Hill, C.M. (2015). Changing agricultural practices and human-chimpanzee interactions: tobacco and sugarcane farming in and around Bulindi, Uganda. In: State of the Apes. Volume II: Industrial Agriculture and Ape Conservation, ed. Arcus Foundation. Cambridge University Press: Cambridge, UK, pp. 29–31.
McLennan, M. R., & Asiimwe, C. (2016). Cars kill chimpanzees: case report of a wild chimpanzee killed on a road at Bulindi, Uganda. Primates, 57(3), 377-388. https://doi.org/10.1007/s10329-016-0528-0
McLennan, M. R., Hasegawa, H., Bardi, M., & Huffman, M. A. (2017). Gastrointestinal parasite infections and self-medication in wild chimpanzees surviving in degraded forest fragments within an agricultural landscape mosaic in Uganda. PLOS ONE, 12(7), e0180431. https://doi.org/10.1371/journal.pone.0180431
McLennan, M. R., Mori, H., Mahittikorn, A., Prasertbun, R., Hagiwara, K., & Huffman, M. A. (2018). Zoonotic Enterobacterial Pathogens Detected in Wild Chimpanzees. EcoHealth, 15(1), 143-147. https://doi.org/10.1007/s10393-017-1303-4
McLennan, M. R. (2018). Tie one on: ‘nest tying’ by wild chimpanzees at Bulindi—a variant of a universal great ape behavior?. Primates, 59(3), 227-233. https://doi.org/10.1007/s10329-018-0658-7 McLennan, M. R., Howell, C. P., Bardi, M., & Heistermann, M. (2019a). Are human-dominated landscapes stressful for wild chimpanzees (Pan troglodytes)? Biological Conservation, 233, 73-82. https://doi.org/10.1016/j.biocon.2019.02.028
McLennan, M. R., Rohen, J., Satsias, Z., Sabiiti, T., Baruzaliire, J. M., & Cibot, M. (2019b). ‘Customary’use of stick tools by chimpanzees in Bulindi, Uganda: update and analysis of digging techniques from behavioural observations. Revue de primatologie,10, https://doi.org/10.4000/primatologie.6706
McLennan, M. R., Lorenti, G. A., Sabiiti, T., & Bardi, M. (2020). Forest fragments become farmland: dietary response of wild chimpanzees (Pan troglodytes) to fast‐changing anthropogenic landscapes. American Journal of Primatology, 82(4), e23090. https://doi.org/10.1002/ajp.23090
Ota, N., Hasegawa, H., McLennan, M. R., Kooriyama, T., Sato, H., Pebsworth, P. A., & Huffman, M. A. (2015). Molecular identification of Oesophagostomum spp. from ‘village’ chimpanzees in Uganda and their phylogenetic relationship with those of other primates. Royal Society Open Science, 2(11), 150471.https://doi.org/10.1098/rsos.150471

Page completed by: Matthew McLennan, Maureen McCarthy & Jack Lester Date: 04/01/2021