New Report Documents Shocking Collapse of Gorilla Subspecies During 20 Years of Civil Unrest

Several actions needed to stop loss of subspecies: Gazette the boundaries of Itombwe Natural Reserve and Punia Gorilla Reserve as well as tackle illegal mining inside protected areas

  • Numbers of Grauer’s Gorilla, the world’s largest primate, have plummeted 77 percent in the last two decades
  • Fewer than 4,000 gorillas remain
  • Last strongholds are protected by ICCN, WCS, WWF, Fauna & Flora International, UGADEC, JGI, DFGFI and GO
  • Civil unrest, illegal hunting, and mining have all contributed to gorilla loss
  • Park guards continue to be killed; latest death occurred on March 31st
  • Grauer’s Gorilla is only found in eastern Democratic Republic of Congo
  • Study calls for “critically endangered” designation for imperiled gorilla

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KINSHASA, DEMOCRATIC REPUBLIC OF CONGO (April 4, 2016) – A shocking new report by the Wildlife Conservation Society (WCS) and Fauna & Flora International documents a catastrophic collapse of the world’s largest great ape– the Grauer’s gorilla – due to a combination of illegal hunting around mining sites and settlements, prior civil unrest, and habitat loss.

The results of the report point to a 77 percent drop in gorilla numbers, from an estimated 17,000 in 1995 to just 3,800 individuals today. Grauer’s gorillas – the world’s largest gorilla subspecies weighing up to 400 pounds – are closely related to the better known mountain gorilla. The subspecies is restricted to eastern Democratic Republic of Congo (DRC).

ICCN, WCS, Fauna & Flora International and other partners are calling for the following additional actions to reverse the decline of Grauer’s gorillas. 

1.      Legally gazette the boundaries of Itombwe Natural Reserve and Punia Gorilla Reserve

2.      Tackle illegal mining inside protected areas and pursue the legal establishment of artisanal mining cooperatives in areas close to gorilla habitats

3.      Disarm militia groups operating in the region

4.      Support park staff and community ecoguards that they are protecting gorillas and their habitat

5.      Find alternative sources of income for local people other than employment from mining

6.      Lobby cellphone/tablet/computer companies and others to ensure that source minerals from this region are purchased from mining sites that do not hunt bushmeat and are conflict free

The survey was led by experts from WCS and Fauna & Flora International, with field data gathered from across the Grauer’s gorilla range by a group of collaborating organizations. The report, funded by the Arcus Foundation, analyzed data collected with support from Critical Ecosystem Partnership Fund, KfW (German Development Bank), ICCN, Newman’s Own Foundation, Rainforest Trust, UNESCO, USAID, U.S. Fish and Wildlife Service, and World Bank. Results were presented at a press conference in Kinshasa.

The authors of the report say that their findings justify raising the threatened status of the Grauer’s gorilla as “critically endangered” on the IUCN list of Threatened Species, highlighting the perilous position these great apes are in, and the need to act now to prevent a further decline in numbers. This would put all four gorilla subspecies in the critically endangered category, the highest category ranking.  

Casualties of war / Plummeting numbers

The decline in Grauer’s gorillas can be traced back to the Rwandan genocide in 1994, which forced hundreds of thousands of refugees to flee to the DRC. This in turn led to the DRC civil war in 1996, which continued until 2003 with devastating consequences, including an estimated 5 million people killed. But beyond the human tragedy, the war has also taken its toll on the DRC’s wildlife as a result of insecurity, heightened illegal bushmeat trade and increased deforestation.

The authors of the report sought to assess the impact of the civil war on Grauer’s gorilla numbers, which were estimated at 17,000 before the conflict. Field teams conducted widespread surveys, the most intensive ever for this ape, in regions beset by insecurity, searching for ground nests and other signs of this elusive ape. In addition, the authors employed a novel method that allowed them to rigorously assess data collected by local community members and rangers to estimate Gorilla abundance.

The survey results confirmed their worst fears: numbers had plummeted to an estimated 3,800 individuals – a shocking 77 percent decline.

One of the primary causes of the decline in Grauer’s gorilla numbers has been the expansion in artisanal mining for coltan (a key mineral used in the manufacture of cell phones and other electronics) and other minerals in the gorilla’s range. Most of these artisanal mining sites are remote, which means that the miners often turn to local wildlife for food. Although protected by law, gorillas are highly prized as bushmeat due to their large size and because they are easily tracked and killed as they move in groups on the ground in their small home ranges.

Turning the tide

The authors say that halting and reversing the decline of Grauer's gorilla will take considerable effort and will require more funding than is currently available. Artisanal mining must be controlled and the various armed groups that control mines disarmed. To accomplish this, it will be necessary to halt mining in protected areas, as it is known that miners subsist on bushmeat and hunt gorillas around their camps. 

Three areas are now particularly crucial for the gorilla’s survival: Kahuzi-Biega National Park, the adjacent Punia Gorilla Reserve where WCS is supporting local communities to establish the reserve and manage and protect gorillas, and the remote unprotected Usala Forest which has no support currently. The Itombwe Reserve and the Tayna regions also support highly-important outlying populations. It is critical to formally gazette the Itombwe and Punia Gorilla Reserves, which have community support but whose boundaries are not yet legally established.

Park guards continue to be at risk.  On March 31st, a guard was killed by armed rebels in an ambush in the forest of the highland sector of Kahuzi Biega National Park, the only site where the study found gorillas were increasing.  

“We urge the government of DRC to actively secure and manage this part of the country for both human welfare as well as the survival of this gorilla,” said the study’s lead author Andrew Plumptre of WCS. “Significantly greater efforts must be made for the government to regain control of this region of DRC. In particular, the government needs to quickly establish the Itombwe Natural Reserve, support local-community management of the Punia Gorilla Reserve, reinforce Kahuzi-Biega National Park efforts, and establish strong coordination between ICCN and the DRC military to tackle armed militias that control illegal mining camps in Grauer’s gorilla heartland.”

Stuart Nixon of Fauna & Flora International (now at Chester Zoo where he has continued his analysis of the survey data), one of the co-authors involved in the study stated, “Grauer's gorilla is found only in the eastern Congo – one of the richest areas on our planet for vertebrate diversity. As one of our closest living relatives, we have a duty to protect this gorilla from extinction. Unless greater investment and effort is made, we face the very real threat that this incredible primate will disappear from many parts of its range in the next five years. It’s vital that we act fast.”

Radar Nishuli, Chief Park Warden for the Kahuzi Biega National Park and another co-author, said: “What we have found in the field is extremely worrying. We are urging a strong and targeted response that addresses the following: Train, support and equip ecoguards to tackle poaching more effectively; build intelligence networks, and support the close daily monitoring of gorilla families to ensure their protection; engage customary chiefs who hold traditional power in the region to educate their communities to stop hunting these apes.”

Said co-author Jefferson Hall, staff scientist at the Smithsonian Tropical Research Institute. “The bright spot in all this is that we have seen, over and over again, dedicated Congolese conservationists risk their lives to make a difference,” Hall said. “Thanks to these individuals, there is still hope and the opportunity to save these animals and the ecosystems they represent.” 


 Report Citation: Plumptre, A.J., Nixon, S., Critchlow, R., Vieilledent, G., Nishuli, R., Kirkby, A., Williamson, E.A., Hall, J.S., & Kujirakwinja, D. (2016). Status of Grauer’s Gorilla and Eastern Chimpanzee: Historical and current distribution and abundance. Unpublished Report to ARCUS Foundation, USAID and US Fish and Wildlife Service. Available at:

 WCS (Wildlife Conservation Society)

MISSION: WCS saves wildlife and wild places worldwide through science, conservation action, education, and inspiring people to value nature. To achieve our mission, WCS, based at the Bronx Zoo, harnesses the power of its Global Conservation Program in nearly 60 nations and in all the world’s oceans and its five wildlife parks in New York City, visited by 4 million people annually. WCS combines its expertise in the field, zoos, and aquarium to achieve its conservation mission. Visit: Follow: @WCSNewsroom. For more information: 347-840-1242.


About Fauna & Flora International (FFI) (

FFI protects threatened species and ecosystems worldwide, choosing solutions that are sustainable, based on sound science and take account of human needs. Operating in more than 40 countries worldwide FFI saves species from extinction and habitats from destruction, while improving the livelihoods of local people. Founded in 1903, FFI is the world’s longest established international conservation body and a registered charity.

About Institut Congolais pour la Conservation de la Nature (ICCN)

The Institut Congolais pour la Conservation de la Nature (ICCN) has a mission to assure the protection of the fauna and flora in the network of protected areas of the Democratic Republic of Congo, to encourage research and tourism and to manage stations for capture and domestication of wild animals. ICCN manages five World Heritage sites including the Virunga National Park, Africa’s oldest park, and the Kahuzi-Biega National Park which conserves a large proportion of the endangered Grauer’s gorilla population. For more information: