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Individual study: The conservation biology framework of the release of wild-born orphaned chimpanzees into the Conkouati Reserve, Congo

Published source details

Tutin C.E.G., Ancrenaz M., Paredes J., Vacher-Vallas M., Vidal C., Goossens B., Bruford M.W. & Jamart A. (2001) The conservation biology framework of the release of wild-born orphaned chimpanzees into the Conkouati Reserve, Congo. Conservation Biology, 15, 1247-1257


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Detect & report dead primates and clinically determine their cause of death to avoid disease transmission Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of reintroduced central chimpanzees Pan troglodytes troglodytes survived over five years when dead chimpanzees were examined to determine their cause of death alongside 16 other interventions. Out of 20 reintroduced chimpanzees, two juveniles were confirmed dead, and one male and three females disappeared. No statistical tests were carried out to determine whether the population decrease was significant. Chimpanzees were radio-collared and followed at distances of 5-100 m. Rehabilitated orphaned chimpanzees underwent vaccination, parasite treatment and veterinary screens before being translocated in four subgroups from the sanctuary to habitat where resident conspecifics occurred. Staff members were permanently present to monitor primate health and provide with additional food if necessary. The area status was upgraded from reserve to national park in 1999. Local people were relocated to a nearby village. Sick or injured chimpanzees were treated. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Keep safety distance to habituated animals Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of reintroduced central chimpanzees Pan troglodytes troglodytes that were monitored directly while maintaining a safety distance along with 16 other interventions, survived over five years. Out of 20 reintroduced chimpanzees that were radio-collared and followed at distances of 5-100 m, fourteen (70%) survived over five years after which the study ended. No statistical tests were carried out to determine whether the population decrease was significant. Rehabilitated orphaned chimpanzees underwent vaccination, treatment for parasites and veterinary screens before being translocated in four subgroups from the sanctuary to the release site with resident wild chimpanzees. Staff members were permanently present to monitor primate health, provide additional food if necessary, and detect and examine dead animals.  The area status was upgraded from a reserve to a national park in 1999. People were relocated from the release site to a nearby village. Some chimpanzees were treated when sick or injured. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Provide non-monetary benefits to local communities for sustainably managing their forest and its wildlife (e.g. better education, infrastructure development) Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of central chimpanzees Pan troglodytes troglodytes that were reintroduced in an area where local people were provided non-monetary benefits for supporting the programme alongside 16 other interventions, survived over five years. Out of 20 reintroduced chimpanzees, fourteen (70%) survived. No statistical tests were carried out to determine whether the population decrease was significant. Local communities were provided emergency medical care and were assisted otherwise. No further details on this intervention were given. Monetary benefits were provided to compensate people for the former use of resources at the site. Rehabilitated orphaned chimpanzees underwent vaccination, parasite treatments and veterinary screens before being radio-collared and translocated in four subgroups to the release site where resident conspecifics occurred. Staff members were permanently present to monitor primate health, provide supplementary food if necessary and examine dead animals. The area status was upgraded from reserve to national park in 1999. Local people were relocated from the release site. Some individuals were treated when sick or injured. TV and radio advertisements were used to raise chimpanzee conservation. The study does not distinguish between the effects of the different interventions mentioned above.

Regularly play TV & radio announcements to raise primate conservation awareness Primate Conservation

A before-and-after study in 1994-1999 in tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of reintroduced central chimpanzees Pan troglodytes troglodytes whose release was broadcasted using various media instruments alongside 16 other interventions, survived over five years. Out of 20 reintroduced chimpanzees, 14 (70%) survived over five years. No statistical tests were carried out to determine whether the decrease was significant. Their release was broadcasted on TV and several illustrated newspaper articles, aiming at raising awareness towards chimpanzee conservation. Individuals were radio-collared and followed at distances of 5-100 m. Rehabilitated orphaned chimpanzees underwent vaccination, parasite treatment and veterinary screens before translocation in four subgroups to habitat where resident chimpanzees occurred. Staff members were permanently present during to monitor primate health, provide additional food if necessary and examine any dead animals. The area status was upgraded from reserve to national park in 1999. Local people were relocated from the release site to a nearby village. Some chimpanzees were treated when sick or injured. Local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Regularly provide supplementary food to primates during resource scarce periods only Primate Conservation

A before-and-after trial in 1994-1999 in tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of reintroduced chimpanzees Pan troglodytes troglodytes that were supplemented with food during resource-scarce periods along with 16 other interventions, survived for at least five years. Out of 20 reintroduced chimpanzees that were provided with supplementary food, fourteen survived (70%). No statistical tests were carried out to determine whether the population decrease was significant. Individuals were radio-collared and followed at distances of 5-100 m. Rehabilitated orphaned chimpanzees underwent vaccination, treatment for parasites and veterinary screens before being translocated in four subgroups from the sanctuary to the release site with resident wild chimpanzees. Staff members were present to monitor primate health and examine any mortality. The reserve status was upgraded to national park in 1999. Local people were relocated from the release site to a nearby village. Some individuals were treated when sick or injured. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Resettle illegal human communities (i.e. in a protected area) to another location Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical dry and swamp forest in Conkouati-Douli National Park, Republic of Congo found that the majority of reintroduced central chimpanzees Pan troglodytes troglodytes survived for at least five years when resident illegal human communities were resettled to another location along with 16 other interventions. Fourteen out of 20 reintroduced chimpanzees (70%) survived until at least the end of the study. No statistical tests were carried out to determine whether the population decrease was significant. Thirteen local people that lived at the release site were moved to a village nearby. Rehabilitated orphaned chimpanzees underwent vaccination, treatment for parasites and veterinary screens before being radio-collared and translocated in four subgroups to the release site where wild chimpanzees lived. Staff members were permanently present to monitor primate health, provide animals with additional food if necessary and detect and examine dead animals. The area status was upgraded from a reserve to a national park in 1999. Some individuals were treated when sick or injured. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Provide monetary benefits to local communities for sustainably managing their forest and its wildlife (e.g. REDD, employment) Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of central chimpanzees Pan troglodytes troglodytes that were reintroduced in an area where local people were provided monetary benefits for supporting the programme alongside 16 other interventions, survived over five years. Out of 20 reintroduced chimpanzees, 14 (70%) survived over five years. No statistical tests were carried out to determine whether the population decrease was significant. To compensate former use of the site, locals received monetary support by being able to sell their products and by being employed as conservation staff. Non-monetary benefits were also provided. Rehabilitated orphaned chimpanzees underwent vaccination, treatment for parasites and veterinary screens before being radio-collared and translocated in four subgroups from the sanctuary to the release site where resident chimpanzees occurred. Staff members were permanently present to monitor primate health, provide supplementary food if necessary and examine dead animals. The area status was upgraded from reserve to national park in 1999. Local people were relocated from the release site. Some individuals were treated when sick or injured. TV and radio advertisements were used to raise chimpanzee conservation. The study does not distinguish between the effects of the different interventions mentioned above.

Remove/treat external/internal parasites to increase reproductive success/survival Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of reintroduced central chimpanzees Pan troglodytes troglodytes that were treated for parasites prior to release alongside 16 other interventions, survived for at least five years. Out of 20 reintroduced chimpanzees that were treated for intestinal parasites when necessary, 14 survived (70%). No statistical tests were carried out to determine whether the population change was significant. Individuals were radio-collared and followed at distances of 5-100 m. Rehabilitated orphaned chimpanzees underwent vaccinations and veterinary screens before being translocated in four subgroups from the sanctuary to the release site where resident chimpanzees occurred. Permanent staff monitored primate health, provided additional food if necessary and examined any dead chimpanzees. The area status was upgraded to a national park in 1999. Local people were relocated from the release site to a nearby village. In some cases, chimpanzees were treated when sick or injured. TV and radio advertisements were used to raise conservation awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Preventative vaccination of habituated or wild primates Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of reintroduced central chimpanzees Pan troglodytes troglodytes that underwent vaccinations prior to release alongside 16 other interventions, survived over five years. Out of 20 reintroduced chimpanzees were vaccinated against polio and tetanus, 14 survived (70%). No statistical tests were carried out to determine whether the population change was significant. Individuals were radio-collared and followed at distances of 5-100 m. Rehabilitated orphaned chimpanzees underwent parasite treatment and veterinary screens before translocation in four subgroups to the release site where resident wild chimpanzees occurred. Staff members were permanently present to monitor primate health, provide additional food if necessary and cinically examine dead animals. The area status was upgraded from reserve to national park in 1999. Local people were relocated from the release site to a nearby village. Some reintroduced chimpanzees were treated when sick or injured. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Rehabilitate injured/orphaned primates Primate Conservation

A before-and-after trial in 1994-1999 in tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of rehabilitated orphaned chimpanzees Pan troglodytes troglodytes that were reintroduced along with 16 other interventions, survived for at least five years. Out of 20 reintroduced chimpanzees that were rehabilitated and socialized with other orphan chimpanzees in a sanctuary before release, 14 (70%) survived. No statistical tests were carried out to determine whether this decrease was significant. Individuals were radio-collared and followed at distances of 5-100 m. Chimpanzees underwent vaccination, parasite treatments and veterinary screens before being translocated in four subgroups to the release site with resident wild chimpanzees. Staff members were present to monitor health conditions, provide additional food when needed, and to examine dead animals. The area’s status was upgraded from reserve to national park in 1999. Local people were relocated from the release site to a nearby village. Some individuals were treated when sick or injured. TV and radio were used to raise awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Permanent presence of staff/manager Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Democratic Republic of Congo found that the majority of reintroduced central chimpanzees Pan troglodytes troglodytes that were permanently monitored by staff alongside 16 other interventions, survived over five years. Out of 20 reintroduced chimpanzees whose health condition was monitored by permanently present staff during the study, fourteen (70%) survived. No statistical tests were carried out to determine whether the population decrease was significant. Individuals were radio-collared. Rehabilitated orphan chimpanzees underwent vaccination, parasite treatments and veterinary screens before being translocated in four subgroups from the sanctuary to the release site where resident conspecifics occurred. Staff members provided supplementary food if necessary and examined dead animals. The area status was upgraded from reserve to national park in 1999. Local people were relocated from the release site. Some individuals were treated when sick or injured. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Legally protect primate habitat Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Republic of Congo, which was upgraded from reserve to national park in 1999 alongside 16 other interventions, found that the majority of reintroduced central chimpanzees Pan troglodytes troglodytes survived over five years. Out of 20 reintroduced chimpanzees released into the legally protected area, 14 (70%) survived. No statistical tests were carried out to determine whether the population decrease was significant. Individuals were radio-collared. Rehabilitated orphaned chimpanzees underwent vaccination, parasite treatments and veterinary screens before being translocated in four subgroups from the sanctuary to the release site where resident conspecifics occurred. Staff members were permanently present to monitor primate health, provide animals with additional food if necessary and detect and examine dead animals. Local people were relocated from the release site to a nearby village. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Treat sick/injured animals Primate Conservation

A before-and-after study in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of reintroduced chimpanzees Pan troglodytes troglodytes that were treated when injured alongside 16 other interventions, survived over five years. Out of 20 reintroduced chimpanzees that were occasionally treated for injuries caused by fights with other chimpanzees, 14 survived (70%). No statistical tests were carried out to determine whether the change was significant or not. Individuals were radio-collared and followed at distances of 5-100 m. Rehabilitated orphaned chimpanzees underwent vaccination, parasite treatment and veterinary screens before translocation in four subgroups from the sanctuary to the release site where resident chimpanzees already occurred. Staff members were permanently present to monitor their health, provide additional food if necessary and detect and examine dead animals. The area status was upgraded from reserve to national park in 1999. Local people were relocated from the release site to a nearby village. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Reintroduce primates into habitat where the species is present Primate Conservation

A before-and-after trial in 1994–1999 in a tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of central chimpanzees Pan troglodytes troglodytes that, alongside 16 other interventions, were reintroduced into a habitat with resident wild chimpanzees survived for at least five years. Fourteen of the 20 (70%) reintroduced chimpanzees that had contact with resident wild chimpanzees, survived. No statistical tests were carried out to determine whether the population decrease was significant. Individuals were radio-collared and followed at distances of 5-100 m. Before being translocated rehabilitated orphaned chimpanzees were vaccinated, treated for parasites, and screened by vets. Staff members were present to monitor primate health, provide animals with additional food if necessary, and determine the cause of death of dead animals. The area was designated a national park in 1999. Local people were relocated from the release site to a nearby village. In some cases, local people were treated when sick or injured. TV and radio advertisements were used to raise awareness of chimpanzee conservation and local people were provided with monetary and non-monetary benefits in exchange for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.

Conduct veterinary screens of animals before reintroducing/translocating them Primate Conservation

A before-and-after trial in 1994-1999 in mixed tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of reintroduced central chimpanzees Pan troglodytes troglodytes that underwent health screens prior to release alongside 16 other interventions, survived for at least five years. Out of 20 reintroduced chimpanzees, whose body conditions were visually assessed and blood, faecal, and hair samples examined for diseases, fourteen (70%) survived. Individuals were radio-collared and followed at distances of 5-100 m. Rehabilitated orphaned chimpanzees underwent vaccination and parasite treatment before being translocated in four subgroups from the sanctuary to the release site where resident conspecifics occurred. Staff members were permanently present to monitor primate health, provide animals with additional food if necessary and examine dead animals when needed. The area status was upgraded from reserve to national park in 1999. Local people were relocated from the release site to a nearby village. Some chimpanzees were treated when sick or injured. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits to support conservation. The study does not distinguish between the effects of the different interventions mentioned above.

Reintroduce primates in groups Primate Conservation

A before-and-after trial in 1994-1999 in tropical forest in Conkouati-Douli National Park, Republic of Congo found that the majority of central chimpanzees Pan troglodytes troglodytes that were reintroduced in groups along with 16 other interventions, survived over five years. Out of 20 reintroduced chimpanzees released in four subgroups from 1996-1999, 14 survived (70%). No statistical tests were carried out to determine whether the population decrease was significant. Individuals were radio-collared. Rehabilitated orphaned chimpanzees underwent vaccination, treatment for parasites and veterinary screens before translocation from the sanctuary to the release site where resident chimpanzees occurred. Staff members were permanently present to monitor primate health, provide additional food if necessary and examine dead animals. The area status was upgraded from reserve to national park in 1999. Local people were relocated from the release site to a nearby village. Some chimpanzees were treated when sick or injured. TV and radio advertisements were used to raise chimpanzee conservation awareness and local people were provided monetary and non-monetary benefits for their conservation support. The study does not distinguish between the effects of the different interventions mentioned above.