The Eastern Lowland Gorilla Is the World's Biggest Gorilla

By: Nicole Antonio & Sascha Bos  | 
Two black gorillas, a mother and son, sit among green leaves
Eastern lowland gorillas eat leaves as part of their herbivorous diet. guenterguni / Getty Images
Key Takeaways
  • The Eastern lowland gorilla is the largest gorilla species, primarily found in the lowland tropical forests of the Democratic Republic of Congo.
  • This critically endangered species faces threats from habitat loss, poaching and civil unrest, with an estimated population of fewer than 5,000 individuals.
  • Conservation efforts include anti-poaching patrols, habitat protection and community-based initiatives to promote coexistence between humans and gorillas.

The Eastern lowland gorilla, scientifically known as Gorilla beringei graueri, is a subspecies of eastern gorilla that inhabits the lush tropical rainforests of the eastern Democratic Republic of the Congo (DRC).

They are the largest gorilla subspecies and are characterized by their stocky build, short muzzle and huge hands. (Mountain gorillas are the other eastern gorillas.)


Join us as we explore the eastern lowland gorilla's habitat, behavior and diet, as well as conservation efforts and threats to the existence of these critically endangered primates.


The Habitat of Eastern Lowland Gorillas

Eastern lowland gorillas reside exclusively in the eastern region of the Democratic Republic of the Congo, specifically in the lowland tropical rainforests.

Their habitat, once spanning approximately 8,100 square miles (20,978 square kilometers), has drastically shrunk over the past 50 years and now covers only about 4,600 square miles (11,914 square kilometers).


These gorillas can be found in national parks such as Kahuzi-Biega National Park and Maiko National Park, as well as in dedicated wildlife reserves. However, habitat destruction and fragmentation have posed significant challenges to their survival.

Habitat Loss and Deforestation

Crucial tracts of eastern lowland gorilla habitat have been lost due to various human activities, including agricultural conversion, timber extraction, livestock ranching, artisanal mining, deforestation and infrastructure development.

The expansion of agriculture and the need for land to sustain a growing population have led to the destruction of vast areas of forest. This loss of habitat has had a devastating impact on the eastern lowland gorilla populations, pushing them into smaller, isolated pockets of forest.

Human Disturbance and Civil Unrest

Living in a conflict zone, eastern lowland gorillas have faced numerous challenges due to the prolonged presence of civil unrest and the armed groups that come with it. Human activity has disrupted their way of life, including feeding patterns and social behaviors.

The constant presence of people involved in extractive industries has intensified the threats faced by these gorillas in recent years.

Oil and Gas Exploration

Another significant threat to the habitat of eastern lowland gorillas is the exploration and extraction of oil and gas. Concessions for oil and gas exploration pose a direct risk to their remaining habitat, further fragmenting the forests and exacerbating the challenges faced by these critically endangered primates.


The Behavior and Social Structure of Eastern Lowland Gorillas

Eastern lowland gorillas are highly intelligent and social creatures, living in close-knit family groups known as troops. These troops are led by a dominant silverback gorilla, who is a large adult male.

Troop Structure and Silverbacks

Eastern lowland gorilla groups typically consist of a dominant silverback male, a multiple females and their offspring.


The silverback is responsible for leading the troop in their daily activities, including feeding and nesting. They also offer protection to the group from external threats.

While the troop size can vary, scientists have observed groups with up to 30 individuals; that said, it is rare to find multiple silverbacks within the same group.

Family Bonds and Offspring

Eastern lowland gorillas exhibit strong family bonds, with females caring for their infants and silverback males forming close relationships with the females. Female gorillas give birth to a single baby after a gestation period of approximately 8.5 months.

The infants remain with their mothers, sharing the same nest, for the first three years of their lives.

Communication and Behavior

Gorillas communicate through a variety of vocalizations, gestures and body postures. They use vocalizations such as grunts, roars and hoots to communicate with other members of their troop.

Body language, including chest-beating and displays of aggression or submission, is also an integral part of their communication system. These behaviors serve to establish dominance, resolve conflicts and maintain social cohesion within the troop.


The Diet of Eastern Lowland Gorillas

Eastern lowland gorillas eat mostly fruits, leaves, shoots, stems, roots and bark.

They also supplement their primarily herbivorous diet with small servings of insects, such as ants and termites. These insects provide an additional source of protein, which is essential for their growth and overall well-being.


Water Intake

Due to their high moisture content, the vegetation consumed by eastern lowland gorillas provides them with sufficient hydration, reducing their need for direct water intake. They rarely drink water directly and rely on the moisture from their diet to meet their hydration needs.


Threats to Eastern Lowland Gorillas: Conservation Challenges

One of the most significant threats to eastern lowland gorillas is poaching for bushmeat. The demand for meat, driven by a constantly expanding human population that has limited access to other protein sources, has resulted in a high and increasing hunting pressure on gorillas.

Miners and militia groups further contribute to the pressure, posing a severe threat to the survival of these primates.


"The dramatic decline in eastern lowland gorilla numbers has been driven primarily by hunting."
- Fauna & Flora

The conversion of forests into agricultural land, timber extraction and infrastructure development have resulted in the fragmentation and destruction of their habitat, further isolating populations and reducing their chances of survival.

Disease Transmission

Gorillas share a significant amount of DNA overlap with humans, making them vulnerable to similar diseases. Human-borne infections can be potentially fatal for gorillas, as they lack natural resistance to these diseases.

The close proximity between habituated gorilla groups and humans, including tourists, increases the risk of disease transmission and poses a constant danger to the survival of eastern lowland gorillas.


Conservation Efforts for Eastern Lowland Gorillas

Conservation organizations, such as Fauna & Flora, have been collaborating with both local communities and authorities alike to establish and manage community reserves for eastern lowland gorillas. These reserves provide protected areas outside of national parks for gorillas to thrive.

Bio-monitoring and Anti-poaching Patrols

To ensure the protection of the dwindling eastern lowland gorilla population and other threatened species, bio-monitoring patrols are conducted regularly in the community reserves.


These patrols involve recording the presence of gorilla groups, removing life-threatening snares and collecting valuable data on their behavior and population dynamics.

Anti-poaching efforts are also crucial in preventing illegal hunting and protecting these critically endangered primates.

Awareness and Education

Raising awareness about the importance of conserving eastern lowland gorillas and their habitat is essential for their long-term survival. Conservation organizations and local partners conduct educational programs, workshops and outreach activities to empower communities with knowledge and encourage sustainable practices.

By fostering environmental stewardship, these initiatives aim to instill a sense of responsibility and pride in protecting these remarkable creatures.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.


Frequently Asked Questions

What adaptations help Eastern lowland gorillas survive in their habitat?
Eastern lowland gorillas have strong, stocky builds and large hands, aiding in climbing and foraging. Their herbivorous diet and social structure also support their survival.
How do Eastern lowland gorillas communicate?
They use vocalizations, gestures and body postures, including chest-beating and roars, to communicate within their troops and establish social hierarchies.