The Eastern Lowland Gorilla (Gorilla beringei graueri), also called Grauer’s Gorilla, is the largest of the world’s four gorilla subspecies. Known for its robust build and dark coat, it is found exclusively in a small, politically volatile region of Africa. This subspecies faces an extinction threat unlike any other great ape. This article provides current population estimates and explores the context of their severe decline.
The Current Population Estimate
The population of the Eastern Lowland Gorilla has collapsed over the last few decades. In the mid-1990s, scientists estimated the wild population at 17,000 individuals. Since then, the number has plummeted by over 77% due to escalating civil unrest and illegal activities across their habitat.
The most recent comprehensive surveys suggest the remaining population is around 6,800 individuals. This figure is an upward revision from the 2016 estimate of 3,800, but it still represents a catastrophic decline from historical numbers. The International Union for Conservation of Nature (IUCN) classifies the Eastern Lowland Gorilla as Critically Endangered, the highest risk category before Extinct in the Wild.
Geographic Range and Habitat
The Eastern Lowland Gorilla is restricted to the forests of the eastern Democratic Republic of Congo (DRC). Their range is discontinuous, covering a mix of lowland tropical rainforests and transitional montane forests along the Albertine Rift escarpment. This subspecies is found across an altitudinal range from 600 meters up to 2,900 meters above sea level.
Key strongholds include the Kahuzi-Biega National Park, the Maiko National Park, the Tayna Gorilla Reserve, and the Itombwe Massif. Much of the remaining population lives outside of strictly protected areas, making them vulnerable to human pressures. Their habitat has shrunk to a fraction of its historical size, further fragmenting gorilla groups.
Major Factors Driving Population Collapse
The primary driver of the population collapse is decades-long instability in the eastern DRC, which has created a lawless environment across the gorilla’s range. The presence of numerous armed groups and militias prevents effective conservation enforcement and allows illegal activities to flourish. This insecurity enables the other major threats to the species’ survival.
Illegal Resource Extraction and Poaching
Illegal resource extraction, particularly mining for minerals like coltan, cassiterite, and gold, leads to habitat fragmentation. Mining camps attract large temporary populations deep into the forest, creating an immediate demand for bushmeat. Poaching is directly linked to these operations, as gorillas are targeted to feed miners and for the illegal trade in infants as pets.
Habitat Loss
Habitat loss is a major threat, driven by the conversion of forest for agriculture and logging. As human populations expand and people are displaced by conflict, they clear forest land for farming and pasturage. This eliminates the gorillas’ food sources and shelter. This clearance breaks up the forest, isolating gorilla groups and limiting their ability to find mates and resources.
Targeted Conservation Efforts
Conservation efforts focus on direct protection for the remaining gorilla groups in the field. Armed anti-poaching patrols, staffed by local rangers, are the first line of defense against illegal hunting and encroachment. Rangers use specialized monitoring systems like SMART (Spatial Monitoring and Reporting Tool) to track patrols and focus efforts on high-risk areas.
A growing emphasis is placed on community-based conservation programs, recognizing that local engagement is necessary for success. Organizations establish community-managed reserves, such as the Nkuba Conservation Area, and create alternative livelihoods for residents. This reduces reliance on forest resources. This strategy aims to foster stewardship among local people by providing employment as trackers and researchers.
Continuous monitoring and research are essential, especially since the Grauer’s Gorilla is less understood than its mountain gorilla cousin. Researchers track the gorillas using nest sites, footprints, and other signs to gather data on population size, health, and range. This information informs the protection strategy.