The Eastern Lowland Gorillas (Gorilla beringei graueri) are a captivating critically endangered subspecies of gorillas that inhabit the lush forests of the Eastern Democratic Republic of Congo.
It covers an area of approximately 2,345,410 square kilometers (905,563 square miles) closely the size of the combined states of Texas, California, Montana, New Mexico, and Arizona in the United States. It is home to a diverse range of wildlife especially eastern owling gorillas, cultures, languages, and natural resources etc.
These Grauer’s Gorillas are found in key populations in several national parks such as Kahuzi Biega National Park, Maiko National Park, Tayna Gorilla Reserve, Usala Forest, and Itombwe Massif.
Relatively other fascinating places or national parks are home to gorillas. These parks include: Virunga National Park home to mountain gorillas in in Congo. Volcanoes National Park is home to mountain gorillas in Rwanda. Bwindi Impenetrable Forest National Park and Mgahinga Gorilla National Park in southwestern Uganda are home to mountain gorillas in Uganda.
As one of the closest relatives to humans, these gentle giants fascinate us with their intelligence, social behaviors, gentle nature, etc.
In this article, we will delve into the world of Eastern Lowland Gorillas, exploring their habitat, genetics, population, diet, social behaviors, conservation efforts, etc.
These are points or facts related to the genetics and species classification of the eastern gorillas as explained below.
The Gorilla genus is divided into two subspecies the eastern gorilla (Gorilla beringei) and the western gorilla (Gorilla gorilla). These two species are primarily found in Equatorial African countries, situated near the equator, with the vast Congo basin forest separating them by approximately 560 miles.
These are further subdivided into four subspecies or four gorilla subspecies. These are eastern lowland gorillas (Gorilla beringei graueri), eastern mountain gorillas (G.b. beringei), western lowland gorillas (G.g. gorilla), and western cross river gorillas (G.g. diehli).
They are one of the closest relatives to humans, sharing about 98.8% of their DNA with humans. The eastern lowland gorilla is scientifically known as “Gorilla beringei graueri” and the species classification and breakdown are;
They have a unique genetic marker, the “Grauer’s gorilla” haplotype. Research studies have identified genetic diversity within the subspecies, suggesting multiple populations but with relatively low genetic diversity compared to other gorilla subspecies. This may be due to historical total population fragmentation and habitat loss.
It’s important to note that the name “Grauer’s gorilla” is derived from the Austrian zoologist and explorer Rudolf Grauer who first recognized the Grauer’s gorilla as a separate subspecies.
Eastern Lowland Gorillas (Gorilla beringei graueri) are the largest of the four-gorilla subspecies that exhibit distinct physical characteristics, including:
In size, Grauer’s gorilla a subspecies of the eastern gorilla is the largest primate of the great apes. Adult males reach up to 1.8 meters (6 feet) tall and weighing 150-220 kg (330-485 lbs) and females weighing in at 178 pounds (81 kg) and reaching 1.6 meters (5.2 ft).
Males have a flat, broad face with a prominent forehead, a short snout (nose prints), and a distinctive crest. Their head has strong, large jaws with thick teeth, dark and expressive eyes, and a wide, flat nose.
Females tend to have narrower faces!
Grauer’s Gorillas (Gorilla beringei graueri) have stocky bodies, broad chests, strong and large powerful arms, sharp nails, relatively short legs. They have muscular long arms with prominent shoulder muscles.
The shorter fur of Grauer’s gorilla is thick and dark brown to jet-black, with a reddish-brown tint on their backs.
Eastern gorillas are permanent residents of the Eastern Democratic Republic of the Congo, spanning across the Albertine Rift region.
They are found in lowland forests, montane forests (mountainous forests), cloud forests, bamboo forests, swamp forests, and other natural habitats.
The eastern lowland gorilla habitat is evenly distributed in the eastern Democratic Republic of the Congo, These areas include the Virunga Mountains, Kahuzi Biega National Park, Virunga National Park, Maiko National Park, Tayna Gorilla Reserve, Usala Forest, Itombwe Massif, North Kivu Province, South Kivu Province, and Maniema Province.
The eastern lowland gorillas live in areas with elevations and higher altitudes ranging from 600 to 3,300 meters above sea level. They are often characterized by high rainfall (1,500-2,000 mm per year), high humidity (70-90%), cooler temperatures (10-15°C/50-59°F), steep terrain and dense vegetation.
The estimated total population of Grauer’s gorilla or eastern lowland gorilla populations is approximately 3,800 individuals per 2006 estimates. They have a population density of 0.4-1.7 individuals per square kilometer, making them one of the most endangered subspecies of gorillas.
The Eastern gorillas tend to be fewer compared to the western lowland gorillas (western gorillas). According to a 2004 report, there were only about 5,000 eastern lowland gorillas in the wild. This is fewer than 3,800 in 2016, compared to over 100,000 western lowland gorillas (western gorillas).
Eastern Lowland Gorillas (Gorilla beringei graueri) are herbivores. They have nutrition needs such as high fiber, protein intake, essential vitamins, and minerals, and their diet consists of:
Eastern gorillas have a specialized digestive system with a large cecum, allowing them to break down cellulose and thrive on a high-fiber, low-protein diet. Please note wild Gorillas do not eat banana fruits, but they may destroy banana trees to eat the nutritious pith.
Eastern Lowland Gorillas (Gorilla beringei graueri) reach maturity between 12-15 years old and some of the age and maturity dynamics are as follows:
These refer to the social characteristics and behaviors of the Grauer’s gorilla which include hierarchy, communication, cooperation, play, etc.
They live in stable groups or troops (~5-30 individuals) arranged in a harem structure. The silverback leads the gorilla family group, followed by adult females and their offspring. The family groups of Eastern Lowland Gorillas (Gorilla beringei graueri) have a complex social hierarchy comprised of dominant male (silverback) > subordinate males >adult female > juveniles > infants.
Please note there exist female-led troops led by a dominant female, especially in Grauer’s gorilla.
The social relationships and interactions amongst eastern lowland gorillas have oftentimes made them be termed as intelligent and social gentle giants and this is proven through these major facts.
Eastern gorillas communicate in various ways, to convey information, express emotions, and maintain social bonds within their groups. Some of these ways include;
Through these diverse communication strategies, Grauer’s gorillas effectively share information, articulate emotions, and foster strong social connections, thereby nurturing cohesive bonds within their groups.
Eastern gorillas possess impressive intellectual abilities which often make people relate them to humans and these include;
1) Problem-Solving
They use tools, like sticks, to extract food or navigate their environment for example when crossing rivers.
2) Memory And Recall
They always remember and recognize individual group members in their troops, even after long separations.
3) Self-Awareness
These gorillas demonstrate an understanding of their own identity and individuality which makes them highly intelligent primates.
4) Spatial Awareness
Eastern gorillas can navigate complex natural habitats and remember the location of food sources and shelter even if they travel miles away from them.
5) Cognitive Flexibility and Imitation
They adapt to new situations and adjust their behavior accordingly through imitation or replication of actions and behaviors observed in others.
6) Innovation
They are highly innovative and creative beings who can create new solutions to problems or find better ways to achieve a goal.
The intricate social dynamics of the eastern gorilla reveal a sophisticated and multifaceted society. It also shows underscoring of their exceptional intelligence, emotional acuity, and ability to adapt to their environment.
This relatively long period is likely because gorillas are large, complex primates with a developed brain and physical abilities that require a longer fetal development period.
The gestation pattern in the eastern gorilla often follows the pattern listed below;
Females often give birth to a single infant (baby gorilla), and breastfeed for about three years. The infants crawl at around nine weeks old and can walk at about 35 weeks old.
Infant Gorillas usually stay with their mother for 3-4 years and mature at around 8 years old (females) and 12 years old (males). Female gorillas typically give birth to 2-6 offspring in their lifetime, with a 6–8-year interval between births. It’s worth noting that individual factors like health, nutrition, and environment can slightly affect the gestation pattern.
Grauer’s Gorillas face numerous threats that have led to them being considered critically endangered species and highly ranked on the red list. Some of the threats include:
Some of the causes of habitat losses are disastrous Fires, Charcoal production, logging, Infrastructure development. Deforestation, and agricultural expansion also lead to habitat destruction and fragmentation.
These activities and issues leave eastern gorillas without natural habitats to stay in, as well as reduced food availability. Further more, massive isolation of gorilla groups, higher risk of transmission of diseases, reduced genetic diversity, high vulnerability to climate change, are threats to the existence of gorillas.
Gorilla species are hunted for their bush meat, and infants are captured for the pet trade. Both these often lead to a rapid decline in the numbers of eastern lowland gorillas posing a threat to their existence.
The outbreaks of diseases like Ebola and COVID-19 which pose significant threats to gorilla populations as well as increased risks of transmission of diseases from humans. They have led to numerous deaths of these gorilla populations in the Democratic Republic of the Congo a major threat to their existence.
The rising temperatures and changing precipitation patterns in the Democratic Republic of the Congo have time and time again altered the natural habitat and food availability of the Grauer’s gorilla. This is a big threat to the existence of these gentle giants.
As natural habitats overlap with human-centered placements, there have been a record number of cases where gorillas raid crops or damage property of the humans, leading to retaliation against them and sometimes resulting in dire consequences such as death, which reduces the number of gorillas.
This human activity which involves extractions (timber extraction) and illegal mining by artisanal miners, leads to extreme damage to gorilla natural habitats and disrupts gorilla behavior which is a big threat to these primates in Congo.
It sometimes also leads to deforestation which destroys natural habitats leaving these primates with no habitats to live in.
Civil unrest or civil wars in the Democratic Republic of Congo which make military groups or armed groups and rebels stay and fight in the mountainous forests of eastern DRC for long periods has resulted in a rapid decline in eastern gorillas as explained below;
i. Habitat Destruction
Due to the continuous stays in the natural habitats of the gorillas which are forests, militia groups or rebels tend to settle in the forests, and carry out logging, illegal mining, human encroachment, and agriculture leading to habitat loss and fragmentation.
ii. Poaching
When rebels hiding in the forests get hungry, they often hunt and kill the Gorillas for bushmeat and illegal trade which greatly reduces their numbers posing a threat to their existence.
Additionally, conflicts also lead to reduced access to food and resources as there can be disruption of food supplies to communities in the forests. This leads to malnutrition and increased poaching which is a big threat to gorillas.
iii. Disruption Of Conservation Efforts
Armed Conflict hinders conservation activities, research, patrols, park guards, and monitoring often required and done in the forests by conservation officers, and park rangers, making it challenging to protect gorilla habitats. This poses a big threat to the primates.
Conflict can also lead to the diversion of funding and resources away from conservation efforts as funders are often limited from accessing the gorilla habitats during civil unrest.
Civil wars and unrest or unstable situations led to the settlement of humans in the gorilla habitat leading to close proximities between humans and gorillas. This often lead to increased transmission of diseases from humans to gorillas which kills off most primates and hence reduces their numbers.
Some populations in some family groups are quite small, and isolated making them more vulnerable to extinction as the reproduction rates are very low in such gorilla groups.
Protecting Grauer’s gorillas requires collaborative conservation, research, and support to address these threats and preserve their habitats.
Conservation efforts are underway to protect the eastern gorilla and their habitats with organizations. These include the International Union for Conservation of Nature (IUCN), the Dian Fossey Gorilla Fund International, and the World Wildlife Fund. They work tirelessly to monitor populations, protect natural habitats, and engage local communities in conservation efforts.
The DR. Congo government is also working closely with these organizations and putting up efforts to protect gorillas and their habitats. This is done by setting up protected areas, raising local awareness, and enforcing gorilla legal protection laws regulating gorilla capture, hunting, poaching, regulations on human activities near habitats etc.
Eastern lowland gorillas are Critically Endangered, with fewer than 6,000 remaining in the wild.
Grauer’s Gorillas coexist peacefully within their groups, shunning conflicts with other gorilla groups. They only displaying aggressive behavior when they perceive a threat from outsiders encroaching on their territory or threatening their safety.
Eastern gorillas are critically endangered because they face a range of threats to their survival, including poaching, habitat loss, civil unrest, disease, and climate change.
Eastern lowland gorillas have a mostly herbivorous diet, eating plants like leaves, stems, and fruit, plus some invertebrates for extra protein.
Eastern Lowland Gorillas being the largest of the four-gorilla subspecies are fascinating creatures that face numerous threats to their survival. They are still standing in the dense forests of the Democratic Republic of Congo. Visit DRC today to explore these gentle giants with us Prime Safaris and Tours Ltd.
Cate
Samuel
Get top notch safari advice: Call us or schedule a video meeting with our experts.
