Grauer’s gorilla community-led ranger patrols in the Democratic Republic of Congo locate undocumented groups, easing threats facing this Critically Endangered subspecies.
Grauer’s gorilla, the world’s largest gorilla subspecies, is holding on in a shrinking corner of eastern Democratic Republic of Congo. Also known as the eastern lowland gorilla, it now numbers around 6,800 individuals in the wild. That is still less than half the population recorded three decades ago.
Surveys once counted about 17,000 Grauer’s gorillas roaming these forests in the mid-1990s. Hunting, habitat loss, and years of armed conflict drove that number down sharply. The subspecies is now classified as Critically Endangered on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.
Grauer’s gorilla lives only in a discontinuous stretch of montane and lowland rainforest east of the Congo Basin. Key strongholds include Kahuzi-Biega and Maiko National Parks. Roughly three-quarters of its remaining habitat sits outside any formally protected park or reserve.
The subspecies is named after Rudolf Grauer, an Austrian explorer who first documented it separately. Unlike its more famous cousin, the mountain gorilla, it ranges across a far wider stretch of forest, from low valleys to cloud-covered peaks. That wide altitudinal range is unmatched by any other gorilla subspecies, though it has not spared the population from steep decline.
Of the four recognized gorilla subspecies, only the mountain gorilla has seen numbers grow in recent years thanks to sustained cross-border protection efforts. The subspecies profiled here, along with the western lowland gorilla and the rare Cross River gorilla, continues to lose ground. Their fates depend heavily on stable funding and secure access to remaining forest.
These gentle giants live in close family groups of up to 30 members. A dominant silverback leads each group, accompanied by several adult females. They feed mostly on leaves, bark, vines, and fruit, spending much of their time on the forest floor.
Grauer’s gorilla lives in close family groups of up to 30, led by a dominant silverback, spending most of their time on the forest floor foraging for leaves, bark, vines, and fruit. Photo by Karl Ammann, courtesy of Fauna & Flora.
Poaching remains the single biggest driver of decline. Rising demand for bushmeat, combined with pressure from armed militias and informal miners, keeps hunting rates high. Deforestation for farmland, logging, and mining is steadily shrinking the forest gorillas depend on.
Decades of conflict in eastern Congo have compounded these threats. Armed groups disturb gorilla behavior and feeding patterns even where hunting itself is limited. Because gorillas share so much genetic material with humans, they are also vulnerable to human diseases carried by nearby communities.
Conservation group Fauna & Flora has worked with local communities since 2011 to protect Grauer’s gorilla and its habitat. Efforts center on three community forests west of Maiko National Park covering about 1,500 square kilometers. These forests act as a buffer zone for a park that is largely inaccessible due to militia presence.
Locally recruited rangers carry out monthly patrols across this buffer zone. They track gorilla groups alongside other threatened species, including chimpanzees, okapi, and Congo peafowl. Along the way, rangers remove snares that can maim or kill gorillas and other wildlife.
This community-led approach has produced a welcome surprise. Patrol teams have located several Grauer’s gorilla groups that earlier surveys never recorded, mostly in remote high-altitude forest far from human activity. As more patrol teams join the effort, additional undocumented groups keep turning up.
Alongside monitoring, the project supports rural households with cleaner, more efficient cookstoves. These reduce the need to collect firewood from gorilla habitat, easing pressure on the forest. Better livelihoods for local communities go hand in hand with stronger protection for wildlife.
Maintaining genetic diversity across scattered gorilla populations remains a long-term priority. Conservationists say connecting habitat fragments, both inside and outside official parks, is essential for the subspecies to recover. As the IUCN Red List assessment notes, an estimated population drop of 77% in one generation justified its Critically Endangered status.
Insecurity in the region remains an ongoing challenge for conservation teams. Even so, community trust built through years of joint patrols is helping close gaps left by inaccessible parkland. Continued support for local rangers offers one of the clearest paths toward a future where Grauer’s gorilla can recover.
