Human Fatality by Escaped Pan troglodytes in Sierra Leone


In April 2006, a group of chimpanzees escaped from the Tacugama Chimpanzee Sanctuary in Sierra Leone, resulting in the death of 1 local citizen and injury of another. The chimpanzees caused no further damage after the initial incident. Of the 31 escaped chimpanzees, 27 returned to the sanctuary by the end of 2006, 21 of them voluntarily. The sanctuary is in a forest reserve, a habitat of wild chimpanzees. Ironically, the tragic incident provided an opportunity to observe the behavior of the escaped chimpanzees and their adaptability in the forest. As a result of the incident, local communities could have come to fear the chimpanzees or develop negative feelings toward the sanctuary and its activities, which include keeping a colony of orphaned chimpanzees for rehabilitation and promoting the protection of wild populations. However, collaboration and understanding among the sanctuary, local communities, and government authorities resulted in peaceful handling of the situation and the humane retrieval of 27 of the escaped chimpanzees. As the number of chimpanzees in African sanctuaries increases, they are responsible more than ever for minimizing hazards to surrounding communities. It is important for sanctuaries to develop understanding and to raise support from local communities and government authorities to help them avoid crises and continue their activities.

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  1. Alp, R., Brima, J., Amarasekaran, B., & Tucker, W. (1993). Chimpanzee Rehabilitation in Sierra Leone, West Africa: Survey Results and Preliminary Proposals. Freetown, Sierra Leone: The Ministry of Agriculture, Forestry and Fisheries.

    Google Scholar 

  2. Anonymous (2005a). Chimps escape, attack visitors at animal sanctuary. Laboratory Primate Newsletter, 44, 21.

    Google Scholar 

  3. Anonymous (2005b). Escaped chimps attack visitors in California. IPPL News, 32, 7–8.

    Google Scholar 

  4. Ausden, M., & Wood, P. (1990). The Wildlife of the Western Area Forest Reserve, Sierra Leone. Forestry Division of the Government of Sierra Leone, Conservation Society of Sierra Leone, International Council for Bird Preservation, Royal Society for the Protection of Birds, Freetown, Sierra Leone.

  5. Barrie, A. (1999). The Structure and Floristic Composition of the Tacugama Forest Reserve: A Potential Habitat for the Release of Rehabilitated Chimpanzees in Sierra Leone. BSc dissertation, Njala University, Freetown, Sierra Leone.

  6. Beck, B., Stoinski, T. S., Hutchins, M., Maple, T. L., Norton, B., Rowan, A., Stevens, E. F., et al. (2001). Great apes and humans: The ethics of coexistence. Washington, DC: Smithsonian Institution Press.

    Google Scholar 

  7. Beck, B., Walkup, K., Rodrigues, M., Unwin, S., Travis, D., & Stoinski, T. (2007). Best practice guidelines for the reintroduction of great apes. Gland, Switzerland: IUCN/SSC Primate Specialist Group.

    Google Scholar 

  8. Borner, M. (1985). The rehabilitated chimpanzees of Rubondo Island. Oryx, 19, 151–154.

    Article  Google Scholar 

  9. Brewer, S. (1977). Chimpanzee Rehabilitation., The International Primate Protection League, South Carolina.

  10. Brewer, S. (1978). The Chimps of Mt. Asserik. New York: Alfred A. Knopf.

    Google Scholar 

  11. Carter, J. (1988). Freed from keepers and cages, chimps come of age on Baboon Island. Smithsonian, 19, 36–49.

    Google Scholar 

  12. Carter, J. (2003). Orphan chimpanzees in West Africa: Experiences and prospects for viability in chimpanzee rehabilitation. In West African Chimpanzees: Status Survey and Conservation Action Plan. IUCN—World Conservation Union, Gland, Switzerland, pp. 157–167.

  13. Cavalieri, P., & Singer, P. (1993). The Great Ape Project: Equality Beyond Humanity. London: Fourth Estate.

    Google Scholar 

  14. Chapman, C. A., & Wrangham, R. W. (1993). Range use of the forest chimpanzees of Kibale: Implications for the understanding of chimpanzee social organization. American Journal of Primatology, 31, 263–273. doi:10.1002/ajp.1350310403.

    Article  Google Scholar 

  15. Cox, D., Rossen, N., Montgomery, C., & Seal, U. S. (2000). Chimpanzee Sanctuaries: Guidelines and Management Workshop Report. Entebbe, Uganda: Conservation Breeding Specialist Group (CBSG/IUCN).

    Google Scholar 

  16. Farmer, K. H. (2002). Pan-African Sanctuary Alliance: Status and range of activities for great ape conservation. American Journal of Primatology, 58, 117–132. doi:10.1002/ajp.10054.

    PubMed  Article  Google Scholar 

  17. Goossens, B., Funk, S. M., Vidal, C., Latour, S., Jamart, A., Ancrenaz, M., et al. (2002). Measuring genetic diversity in translocation programmes: Principles and application to a chimpanzee release project. Animal Conservation, 5, 225–236. doi:10.1017/S1367943002002275.

    Article  Google Scholar 

  18. Goossens, B., Setchell, J., Vidal, C., Dilambaka, E., & Jamart, A. (2003). Successful reproduction in wild-released orphan chimpanzees (Pan troglodytes troglodytes). Primates, 44, 67–69.

    PubMed  Google Scholar 

  19. Goossens, B., Setchell, J., Tchidongo, E., Dilambaka, E., Vidal, C., Ancrenaz, A., et al. (2005). Survival, interactions with conspecifics and reproduction in 37 chimpanzees released into the wild. Biological Conservation, 123, 461–475. doi:10.1016/j.biocon.2005.01.008.

    Article  Google Scholar 

  20. Hannah, A. C., & McGrew, W. C. (1991). Rehabilitation of captive chimpanzees. In H. O. Box (Ed.), Primate responses to environmental change (pp. 167–186). London: Chapman & Hall.

    Google Scholar 

  21. Hasegawa, T. (1990). Sex differences in ranging patterns. In T. Nishida (Ed.), The Chimpanzees of the Mahale Mountains: Sexual and Life History Strategies (pp. 99–114). Tokyo: University of Tokyo Press.

    Google Scholar 

  22. Herbinger, I., Boesch, C., & Rothe, H. (2001). Territory characteristics among three neighboring chimpanzee communities in the Taï National Park, Côte d’Ivoire. International Journal of Primatology, 22, 143–167. doi:10.1023/A:1005663212997.

    Article  Google Scholar 

  23. Hockings, K. J. (2007). Human-Chimpanzee Coexistence at Bossou, the Republic of Guinea: A chimpanzee Perspective. Ph.D. dissertation, University of Stirling.

  24. Hockings, K. J., Anderson, J. R., & Matsuzawa, T. (2007). Road crossing in chimpanzees: A risky business. Current Biology, 16, 668–670.

    Article  CAS  Google Scholar 

  25. Kindschuh, H. (2005). Three chimps shot after escape from Zoo Nebraska, Lincoln Journal Star, January 16, 2007).

  26. Kormos, R., Boesch, C., Bakarr, M., & Butynski, T. M. (2003). West African Chimpanzees: Status Survey and Conservation Action Plan. Gland, Switzerland: IUCN—World Conservation Union.

    Google Scholar 

  27. Lehmann, J., & Boesch, C. (2005). Bisexually bonded ranging in chimpanzees (Pan troglodytes verus). Behavioral Ecology and Sociobiology, 57, 525–535. doi:10.1007/s00265-004-0891-5.

    Article  Google Scholar 

  28. Mills, W., Cress, D., & Rosen, N. (2005). Pan African Sanctuary Alliance (PASA) 2005 Workshop Report. Conservation Breeding Specialist Group (SSC/IUCN), Mona Foundation. (2007). A Very Sad Day for Mona. Mona Foundation, Girona, Spain, (Accessed January 16, 2008).

  29. Ohashi, G. (2005). Deactivation of snares by wild chimpanzees. Primate Report, 21, 68.

    Google Scholar 

  30. Pan African Sanctuary Alliance. (2007). PASA Handbook 20062007, Pan African Sanctuary Alliance.

  31. Statistics Sierra Leone. (2006). 2004 Population and Hosing Census. Statistics Sierra Leone, the Government of Sierra Leone.

  32. Teleki, G. (2001). Sanctuaries for ape refugees. In B. B. Beck, T. S. Stoinski, M. Hutchins, T. L. Maple, B. Norton, A. Rowan, E. F. Stevens, & A. Arluke (Eds.), Great Apes & Humans: The ethics of Coexistence (pp. 133–149). Washington, DC: Smithsonian Institution Press.

    Google Scholar 

  33. Treves, A., & Naughton-Treves, L. (1997). Case study of a chimpanzee recovered from poachers and temporarily released with wild conspecifics. Primates, 38, 315–324. doi:10.1007/BF02381618.

    Article  Google Scholar 

  34. Tutin, C., Ancrenaz, E. G., Paredes, M., Vacher-Vallas, J., Vidal, M., Goosens, C., et al. (2001). Conservation biology framework for the release of wild-born orphaned chimpanzees into the Conkouati reserve, Congo. Conservation Biology, 15, 1247–1257. doi:10.1046/j.1523-1739.2001.00046.x.

    Article  Google Scholar 

  35. Williams, J. M., Pusey, A. E., Carlis, J. V., Farm, B. P., & Goodall, J. (2002). Female competition and male territorial behaviour influence female chimpanzees’ ranging patterns. Animal Behaviour, 63, 347–360. doi:10.1006/anbe.2001.1916.

    Article  Google Scholar 

  36. Wrangham, R. W. (1979). Sex differences in chimpanzee dispersion. In D. A. Hamburg, & E. R. McCown (Eds.),Perspectives on human evolution, vol. 5: The great apes (pp. 481–489). Menlo Park, CA: Benjamin/Cummings.

    Google Scholar 

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The Japan Society for the Promotion of Science (JSPS) core-to-core program HOPE; the Matsushita International Foundation; the Ministry of Education, Science, Sports and Culture; Grant-in-Aid for Scientific Research (Young Scientists A, 18681036, 2006-2008 to Gen Yamakoshi); the JSPS Global COE Program; In Search of Sustainable Humanosphere in Asia and Africa; and JSPS program, Initiatives for Attractive Education in Graduate Schools: Training of Researchers for Applied Area Studies by on Site Education and Research partially funded the study. In Sierra Leone, we thank the former President Dr. Ahmed Tejan Kabbah, Dr. Sama Banya, the police force (Operational Support Division Special Operation), K. Bangura, M. Mansaray, the Wildlife Conservation Branch and the Forestry Division under the National Commission for the Environment (the Government of Sierra Leone), the Conservation Society of Sierra Leone, L. Dotras, W. Tucker, M. Kapia and the rest of the staff at the Tacugama Chimpanzee Sanctuary, M. Mammah, and the people in the communities around the Western Area Forest Reserve, especially in Regent, Bathurst. Charlotte. A. Kabasawa and the Tacugama Chimpanzee Sanctuary extend our sincere sympathies to the family of the deceased, I. Bangura, and the injured, M. Mammah. We thank Pan African Sanctuary Alliance (PASA) for its unfailing assistance and moral supports at all times. A. Kabasawa also thanks Drs. T. Matsuzawa and G. Yamakoshi for their guidance.

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Correspondence to Asami Kabasawa.

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Kabasawa, A., Garriga, R.M. & Amarasekaran, B. Human Fatality by Escaped Pan troglodytes in Sierra Leone. Int J Primatol 29, 1671 (2008).

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  • behavior
  • chimpanzees
  • escape
  • rehabilitation
  • sanctuary
  • Sierra Leone