Bossou
West Africa > Republic of Guinea > Bossou
Summary
- Western chimpanzees (Pan troglodytes verus) are present in Bossou.
- The last population estimate was 7 individuals.
- The chimpanzee population trend is declining.
- This site has a total size of 20 km².
- Key threats to chimpanzees are isolation due to habitat destruction and fragmentation.
- The following conservation activities were implemented: establishing a habitat corridor and environmental education.
- Bossou is one of the longest-running research sites on chimpanzees.
Site characteristics
Bossou is a long-term research site in south-eastern Guinea located 6 km west of the foot of the Nimba mountains (Kormos et al. 2003). The site was established in 1976 by Sugiyama and colleagues from the Kyoto University Primate Research Institute in Japan (Sugiyama 1979). Prior, Kortlandt was the first researcher to study chimpanzees at Bossou in 1960, but continuous research has been ongoing since 1976 (Kormos et al. 2003). Research conducted at Bossou has contributed to the understanding of chimpanzee ecology and behavior through numerous studies as diverse as population dynamics, social structure, feeding behavior, grooming behavior, genetics, tool use (as detailed in Kormos et al. 2003, The chimpanzees of Bossou and Nimba 2019). In 2001 the Institut de Recherche Environnementale de Bossou was established to foster collaboration between the Guinean government and Japanese researchers (Kormos et al. 2003). Only one chimpanzee community remains in the forest surrounding the village of Bossou and ranges in an area of about 20 km2 (Humle 2011). The area is characterized by agricultural areas, secondary forests, savanna and interspersed gallery forests (Sugiyama 1979). The site is not under any formal protection. It was identified as a priority site for conservation in the regional action plan for western chimpanzees (Kormos et al. 2003).
Table 1. Basic site information for Bossou
| Area | 20 km² |
| Coordinates | 7.65, -8.49 |
| Designation | None |
| Habitat types | Arable land, subtropical/tropical heavily degraded former forest, subtropical/tropical moist forest, moist savanna |
IUCN habitat categories Site designations
Ape status
Since the chimpanzee community at Bossou is habituated to the presence of researchers, exact population estimates have been recorded since the 1970s. From 1976 to 2003 chimpanzee abundance fluctuated around 20 individuals (Sugiyama 1981, Kormos et al. 2003, The chimpanzees of Bossou and Nimba 2019). In 2004 the size of the chimpanzee community started to decline and is now at 7 individuals (The chimpanzees of Bossou and Nimba 2019).
Table 2. Ape population estimates in Bossou
| 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 verus | 1967 | 17 | Bossou | Full count | Sugiyama 1979 | likely underestimate as chimpanzees were not yet habituated to human observers (Sugiyama 1979) | |||
| Pan troglodytes verus | 1976 | 21 | Bossou | Full count | Sugiyama 1979 | ||||
| Pan troglodytes verus | 1979-1980 | 20 (19-21) | Bossou | Full count | Sugiyama 1981 | ||||
| Pan troglodytes verus | 2004 | 14 | Bossou | Full count | The chimpanzees of Bossou and Nimba 2019 | ||||
| Pan troglodytes verus | 2018 | 7 | Bossou | Full count | The chimpanzees of Bossou and Nimba 2019 |
Threats
The key threat to chimpanzees is the destruction and fragmentation of habitat which led to the complete isolation of the Bossou chimpanzee community from other chimpanzee groups. The last male chimpanzee migrated into the research group in 1982 (Hirata et al. 1998). In the 1980s other chimpanzee groups in the surrounding area have likely gone extinct (Hirata at el. 1998). 1,500 people live in the village of Bossou. During the civil war in Liberia in the 1990s there was a large influx of migrants from Liberia to Bossou, and the local population almost doubled leading to further deforestation (Matsuzawa et al. 2011a). During the outbreak of a flu-like respiratory disease in 2003 five chimpanzees died (Humle 2011 b). The local population is tolerant towards chimpanzees based on the belief that chimpanzees are reincarnation of their ancestors (Matsuzawa et al. 2011a). Consequently, chimpanzees are not hunted, nor have retaliatory killings as a result of crop raiding by chimpanzees been reported.
Table 3. Threats to apes in Bossou
| Category | Specific threats | Threat level | Quantified severity | Description | Year of threat |
|---|---|---|---|---|---|
| 1. Residential & commercial development | 1.1 Housing & urban areas | Medium | humans live in close proximity chimpanzees, but do not hunt them (Matsuzawa et al. 2011a) | ongoing (2011) | |
| 2. Agriculture & aquaculture | 2.1 Annual & perennial non-timber crops | High | widespread agriculture (Hockings et al. 2012) | Ongoing (2012) | |
| 3. Energy production & mining | Absent | ||||
| 4. Transportation & service corridors | 4.1 Roads & railroads | Medium | chimpanzees need to cross roads to move between habitat patches (Matsuzawa et al. 2011a) | ongoing (2011) | |
| 5. Biological resource use | 5.3 Logging & wood harvesting | High | most of the forest has been destroyed or degraded, especially when many people moved to the area during the Liberian civil war (Matsuzawa et al. 2011a) | until 1990s | |
| 6. Human intrusions & disturbance | Absent | ||||
| 7. Natural system modifications | 7.1 Fire & fire suppression | Low | fire do occur in the area (Matsuzawa et al. 2011a) | ongoing (2011) | |
| 8. Invasive & other problematic species, genes, diseases | 8.1 Invasive non-native/alien species/diseases | Medium | 5 chimpanzees died (Humle 2011b) | outbreak of flu-like respiratory disease killing five chimpanzees (Humle 2011b) | 2003 |
| 9. Pollution | Absent | ||||
| 10. Geological Events | Absent | ||||
| 11. Climate change & severe weather | Unknown | ||||
| 12. Other options | Absent |
Conservation activities
Conservation activities focus on reestablishing habitat connectivity between Bossou and the Nimba mountains to end the isolation of the chimpanzee community (Hirata et al. 1998). In 1997 the [“Green Corridor Project” https://www.greencorridor.info/] started. To overcome the 10 km distance to the Nimba mountains a habitat corridor is being planted of a length of 4 km and 300m wide through savanna areas. Conservation activities also include environmental awareness raising since 1993 through video screenings, pamphlets, educational material for schools and environmental education sessions at schools (Hirata et al. 1998, Humle 2011c). The research project also provided financial support to the construction of schools and latrines, and material donations to schools (e.g., books, benches etc. Humle 2011c). After the outbreak of a respiratory disease in 2003, several measures preventing the spread of human diseases to chimpanzees were implemented: a minimum distance between chimpanzees and humans of 20 m, compulsory wear of a masks, reinforcement of guidelines on disposal of human waste and debris, promoting the construction and usage of latrines in villages, health screening of staff, researchers and tourists working with chimpanzees, and the requirement of up-to-date vaccination by people working with the chimpanzees (Humle 2011b).
Table 4. Conservation activities in Bossou
| Category | Specific activity | Description | Year of activity |
|---|---|---|---|
| 1. Residential & commercial development | Absent | ||
| 2. Agriculture & aquaculture | Absent | ||
| 3. Energy production & mining | Absent | ||
| 4. Transportation & service corridors | Absent | ||
| 5. Biological resource use | Absent | ||
| 6. Human intrusions & disturbance | Absent | ||
| 7. Natural system modifications | Absent | ||
| 8. Invasive & other problematic species, genes, diseases | 8.7. Wear face-masks to avoid transmission of viral and bacterial diseases to primates | since the outbreak of the respiratory disease all people observing chimpanzees have to wear masks (Humle 2011b) | since 2003 |
| 8.8. Keep safety distance to habituated animals | a minimum distance of 20 m is enforced (Humle 2011b) | since 2003 | |
| 8.12. Ensure that researchers/tourists are up-to-date with vaccinations and healthy | up-to-date vaccinations are required (Humle 2011b) | since 2003 | |
| 9. Pollution | Absent | ||
| 10. Education & Awareness | 10.1. Educate local communities about primates and sustainable use | video screenings, pamphlets, educational material for schools and environmental education sessions at schools (Hirata et al. 1998, Humle 2011c) | since 1993 |
| 11. Habitat Protection | 11.7. Restore habitat corridors | the Green Corridor Project aims to reestablish habitat connectivity between Bossou and the Nimba mountains (Matsuzawa et al. 2011a) | since 1997 |
| 12. Species Management | Absent | ||
| 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) | financial support for the construction of schools and latrines, material donations to schools (Humle 2011c) | since end 1990s |
Conservation activities list (Junker et al. 2017)
Challenges
Table 5. Challenges reported for Bossou
| Challenge | Source |
|---|---|
| Not reported |
Research activities
Since 1976 research has been continuously conducted at Bossou covering a wide range of topics from ecology, demography and social organization, tool use, cognition, communication, culture, feeding behavior, genetics, and social behaviors (listed in more detail in Kormos et al. 2003, Matsuzawa et al. 2011b, The chimpanzees of Bossou and Nimba 2019). As chimpanzees at Bossou live in a landscape strongly impacted by anthropogenic activities, one focus of research activities was how chimpanzee are behaving in such a landscape, on crop-raiding behavior by chimpanzees and conflicts between chimpanzees and humans (e.g., Hockings et al. 2012, Hockings et al. 2010).
Documented behaviours
Table 6. Great ape behaviors reported for Bossou
| Behavior | Source |
|---|---|
| Algae scooping | Humle et al. 2011 |
| Ant dipping | Matsuzawa & Humle 2011 |
| Branch shaking | Whiten et al. 1999 |
| Branch slapping | Whiten et al. 1999 |
| Buttress beating | Whiten et al. 1999 |
| Drinking palm wine | Hockings et al. 2015 |
| Hunting and meat eating | Sugiyama 1981 |
| Leaf clipping | Sugiyama 1981 |
| Leaf cushion | The chimpanzees of Bossou and Nimba 2019 |
| Leaf sponging for drinking water | Sugiyama 1981 |
| Medicinal uses of leaves | Matsuzawa & Yamakoshi 1996 |
| Nut cracking (palm nut) | Sugiyama 1981 |
| Pestle pounding | Matsuzawa & Humle 2011 |
| Stem pull-through | Whiten et al. 1999 |
| Stone throwing | Whiten et al. 1999 |
| Termite fishing | Whiten et al. 1999 |
| Wood pounding | Whiten et al. 1999 |
References
Hirata S, Morimura N, and Matsuzawa T. 1998. Green passage plan (Tree planting project) and environmental education using documentary videos at Bossou: a progress report. Pan African News, 5, 18–20.
Hockings KJ et al. 2010. Attacks on local persons by chimpanzees in Bossou, Republic of Guinea: long-term perspectives, American Journal of Primatology, 72:887-896
Hockings KJ et al. 2012. Socioecological adaptations by chimpanzees, Pan troglodytes verus, inhabiting an anthropogenically impacted habitat, Animal Behaviour 83(3) 801-810
Hockings KJ et al. 2015. Tools to tipple: ethanol ingestion by wild chimpanzees using leaf-sponges. Royal Society Open Science, 2: 150150
Humle T. 2011a. Location and ecology, in Matsuzawa T, Humle T and Sugiyama Y, ed. The chimpanzees of Bossou and Nimba. Springer. Tokyo
Humle T. 2011b. The 2003 epidemic of a flu-like respiratory disease at Bossou, in Matsuzawa T, Humle T and Sugiyama Y, ed. The chimpanzees of Bossou and Nimba. Springer. Tokyo
Humle T. 2011c. Environmental education and community development in and around Bossou, in Matsuzawa T, Humle T and Sugiyama Y, ed. The chimpanzees of Bossou and Nimba. Springer. Tokyo
Humle T et al. 2011. Algae scooping remains a puzzle, in Matsuzawa T, Humle T and Sugiyama Y, ed. The chimpanzees of Bossou and Nimba. Springer. Tokyo
Kormos R et al. 2003. The Republic of Guinea, in Kormos, R. Boesch, C., Bakarr, M.I. & Butynski, T.M. [eds.] Status Survey and Conservation Action Plan, IUCN/SSC Primate Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK
Matsuzawa T. and Yamakoshi G. 1996. Comparison of chimpanzee material culture between Bossou and Nimba, West Africa, in Russon AE, Bard KA and Parker ST, eds. Reaching into thought: the minds of the great apes. University Press, Cambridge
Matsuzawa T, Humle T. 2011. Bossou: 33 years, in Matsuzawa T, Humle T and Sugiyama Y, ed. The chimpanzees of Bossou and Nimba. Springer. Tokyo
Matsuzawa T et al. 2011a. Green corridor project: planting trees in the savanna between Bossou and Nimba, in Matsuzawa T, Humle T and Sugiyama Y, ed. The chimpanzees of Bossou and Nimba. Springer. Tokyo
Matsuzawa T et al. 2011b. The chimpanzees of Bossou and Nimba. Springer. Tokyo
Sugiyama, Y. (1979) Social structure and dynamics of wild chimpanzees at Bossou, Guinea. Primates 20(3) 323-339.
Sugiyama, Y. (1981) Observation on the population dynamics and behavior of wild chimpanzees at Bossou, Guinea, in 1979-1980. Primates 22(4) 435-444.
The chimpanzees of Bossou and Nimba (2019) [Green Corridor Project https://www.greencorridor.info/]
Whiten et al. 1999. Cultures in chimpanzees. Nature 399: 682-685
Page completed by: A.P.E.S. Wiki Team Date: 19/07/2019