Grauer’s Gorilla caught in the crossfire of conflict

The International Union for Conservation of Nature (IUCN) and other world leading conservation organisations have joined together to fight for the survival of the Endangered Grauer’s Gorilla, also known as the Eastern Lowland Gorilla (Gorilla beringei graueri).

The entrance to Kahuzi-Biega National Park

Found only in the mountain and mid-altitude forests of eastern Democratic Republic of Congo (DRC), the Grauer's Gorilla is not only the largest of the four gorilla subspecies, but also the largest primate in the world.

“Conserving the remaining Grauer’s Gorilla populations, as well as chimpanzees in the area, requires a dynamic approach and the participation of all areas of society from national government to local communities,” said Dario Merlo of the Jane Goodall Institute.

With their entire range consumed in conflict since 1996, important populations of Grauer’s Gorilla and their chimpanzee relatives (Pan troglodytes schweinfurthii) have gone largely unmonitored. Different sources have offered varying population estimates since that time but their true status is unknown.

The Jane Goodall Institute, Fauna & Flora International (FFI), the Wildlife Conservation Society (WCS), Frankfurt Zoological Society (FZS), Conservation International (CI), the Dian Fossey Gorilla Fund International (DFGFI), and local conservation organisations have partnered with the Institut Congolais pour la Conservation de la Nature (ICCN), the Ministry of the Environment, Nature Conservation and Tourism (MECNT), national military and police authorities, and local communities to support the implementation of a recently completed IUCN Conservation Action Plan for great apes in the eastern DRC.

The action plan represents an important milestone in the conservation of great apes in the DRC, bringing together a large number of government and civilian stakeholders and a panel of ape conservation experts to identify essential actions to slow the decline of gorillas and chimpanzees in the region.

Having identified and agreed on the need for a coordinated and consolidated approach, the in-country teams are now working closely, each taking the lead on a component of the plan while supporting the others with their expertise. One of the key activities identified is the need to assess the true status of gorillas and chimpanzees in the region.

The first ever surveys of Grauer’s Gorilla were carried out in the late 1950s by George Schaller of WCS and John Emlen at a time when it was considered to be the same subspecies as the Mountain Gorilla (Gorilla beringei beringei). The initial surveys concluded that these gorillas were rare and rapidly declining due to habitat destruction, hunting for meat and retaliation for crop raiding.

Subsequent surveys by WCS to establish the status of the subspecies, which did not take place until 1994, included the Kahuzi-Biega National Park and its adjacent forests, the Itombwe Massif and Maiko National Park. These surveys found that gorillas remained highly threatened, primarily from hunting and human settlement, and that several important subpopulations had been lost. Results of these surveys suggested that at the time the region supported approximately 17,000 gorillas.

“In the 1990s, carrying out surveys in this region was challenging, but we did not have to contend with the insecurity that followed,” said Dr Liz Williamson of the IUCN SSC Primate Specialist Group. “Comprehensive follow-up surveys have been impossible until now.”

“The Wildlife Conservation Society, Fauna & Flora International and the Jane Goodall Institute have designed a new scientific approach to survey this Endangered ape across its 80,000 km2 range with statistical help from the Max Planck Institute of Evolutionary Anthropology,” said Dr Andrew Plumptre of WCS. “Together we will be testing a new survey technique that will allow improved future monitoring of this species in a more cost-effective manner. This design will allow us to be more confident about the impacts of the civil war in the DRC on Grauer’s Gorilla numbers.”

“With support from Google, DigitalGlobe and Esri, we are also applying innovative, cutting-edge mobile mapping, satellite imagery, and cloud-based technologies to equip survey teams with high-resolution base maps and enable local communities to contribute to ape monitoring efforts,” added Dr Lilian Pintea of the Jane Goodall Institute.

Since 2003, several attempts have been made to survey parts of the Grauer’s Gorilla range. While results from these preliminary surveys found that gorillas still exist at several key sites, they also documented what appears to be a severe decline of 50–80% since the 1990s.

“Today, the remaining Grauer’s Gorilla populations are small and localised and occur in regions of intense illegal mining activity and insecurity,” said Stuart Nixon of Fauna & Flora International. “Until we can complete the much-needed surveys, our best guess is that between 2,000 and 10,000 gorillas remain in 14 isolated populations. Without a dedicated effort, the next 10 years will be marked by continuing local extinctions of this forgotten gorilla.”

Classified as Endangered on the IUCN Red List of Threatened Species™, the new surveys are vital in assessing if the Grauer’s Gorilla conservation status has changed and to identify the highest priority populations for focused conservation efforts and long-term monitoring.

WCS and FFI will begin implementing the surveys this month.

For more information please contact:

Lynne Labanne, IUCN Species Programme Communications Officer, IUCN, t +41 22 999 0153, m +41 79 527 7221, e

Camellia Williams, IUCN Species Programme Communications, IUCN, t +41 22 999 0154, e

Work area: 
Conservation Planning
West and Central Africa
République Démocratique du Congo
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