Eastern Gorilla

The Eastern Gorilla: The Mother Specie of Mountain Gorilla and Eastern Lowland Gorilla

The eastern gorilla is a critically endangered species of the genus Gorilla and the largest living primate. At present, the eastern gorilla species is subdivided into two subspecies namely, the Eastern Lowland Gorilla (Gorilla beringei graueri) and the Mountain Gorilla. There are approximately 6,800 eastern lowland gorillas also known as Grauer’s gorillas and about 1,000 mountain gorillas in the world. From the tourism perspective, the trekking of both subspecies of the eastern gorillas take place in Democratic Republic of Congo for both mountain gorillas and eastern lowland gorillas and Uganda, Rwanda and Congo for only mountain gorillas.

The Eastern Lowland Gorilla, a subspecies of the Eastern Gorilla

The eastern lowland gorilla or Grauer’s gorilla is a Critically Endangered subspecies of eastern gorilla widespread to the hilly jungles of eastern Democratic Republic of the Congo. Vital populaces of this gorilla live in the Kahuzi-Biega National Park and Maiko National Park and their nearby forests, the Tayna Gorilla Reserve, the Usala forest and on the Itombwe Massif. This primate is the largest of the four gorilla subspecies characterized by a jet black coat like the mountain gorilla even though the hair is shorter on the head and body. The male’s coat, similar to that of other gorillas, greys as the animal matures, resulting in the label “silverback”.

Mountain Gorilla, a Subspecies of the Eastern Gorilla

The mountain gorilla (Gorilla beringei beringei) is one of the two subspecies of the eastern gorilla and is listed as endangered by the International Union for Conservation of Nature (IUCN) as of 2018. The mountain gorillas are found in the Virunga volcanic mountains of Central/East Africa, within the three National Parks including Mgahinga Gorilla National Park in southwest Uganda; Volcanoes National Park in northwest of Rwanda and the Virunga National Park in eastern Democratic Republic of Congo. Other mountain gorillas are found in Uganda’s Bwindi Impenetrable National Park. Some primatologists speculate the Bwindi population is a separate subspecies,[3] though no description has been finalized. As of June 2018, there were more than 1,000 individuals of mountain gorillas in the entire world.

Classification and phylogeny

There are two acknowledged subspecies of eastern gorilla: the mountain gorilla of the volcanic gradients of Rwanda, Uganda and eastern Democratic Republic of Congo as well as the eastern lowland gorilla in eastern Democratic Republic of Congo. Both gorilla subspecies were formerly assumed to be two of the three subspecies of one single species, the gorilla (Gorilla gorilla). Nonetheless, genetic research has revealed that the two eastern subspecies are far more closely connected than the western subspecies. The western lowland gorilla (G. gorilla gorilla), which justified the separate classification. The two eastern subspecies are now classified as G. beringei.

Description of the Easter Gorilla

The eastern gorilla is a bulky hominid with a big head, extensive chest, and lengthy arms. It has got a flat nose with enormous nostrils. The face, hands, feet and breast are bare. The hair is largely black, but adult males have a silvery “lumber” on their backs. When the gorilla ages, the hair on the saddle of the back converts to white, same like the gray hair of aged persons. It is the reason why the older males are termed as silverbacks. Grauer’s gorilla has a shorter, abundant, deep black fur, whereas the mountain gorilla has a more bluish color.

The mountain gorilla is a little smaller and lighter than Grauer’s gorilla, but still heavier and larger than the western lowland gorilla and the Cross River gorilla. Males are much bigger than females. A fully grown male eastern gorilla characteristically weighs 140 to 205.5 kg (309–453 lb) and stands 1.7 m (5.6 feet) upright and a female typically weighs between 90 to 100 kg (200–220 lb) and stands 1.5 m (4.9 feet) tall. The tallest silverback recorded was a 1.95-metre (6.4 feet) individual shot in Alimbongo, northern Kivu in May 1938. The weightiest gorilla recorded was a 1.83-metre (6.0 feet) silverback shot in Ambam, Cameroon, which weighed 267 kilograms (589 lb), though the latter area is the territory of the western gorilla, extremely distanced from that of the eastern gorilla.

Distribution and Ecology of the Eastern Gorilla

The Mountain gorillas are classified to the mountain forest and subalpine forest of eastern Democratic Republic of the Congo (DRC), southwestern Uganda and North Eastern Rwanda. Grauer’s gorilla dwell across the woodlands of the Albertine Rift in eastern DRC.

The Eastern gorillas are herbivorous, with a heavily greenery based diet as a result of lack of accessible fruit in their territories. They have smaller home ranges than western gorillas as vegetation is more abundant than fruit. They are daylight but the majority of searching occurs in the morning and late afternoon. At night, they construct nests by folding over vegetation, usually on the ground.


Eastern gorillas live in stable, cohesive family groups, led by a leading silverback male. Eastern gorillas have a habit of having larger group sizes than their western relatives, numbering up to 35 members. There is no different breeding period and the females produce only once every 3 to 4 years due to the long period of maternal care and a pregnancy period of 8.5 months. Newborn gorillas happen to have greyish-pink skin and can crawl after 9 weeks; they are not fully weaned until 3.5 years. Males defend their females and progeny using their large size in threatening displays involving charging and chest-beating.

Conservation status of Eastern Gorilla

The eastern gorilla has become progressively threatened ever since the 1990s, and the species was recorded as disparagingly in danger of extinction in September 2016 as its population persistently diminished. Prime intimidations to the eastern gorilla include habitat devastation for residential, money-making and agronomic purposes, habitat destruction caused by transportation corridors and resource extraction and diseases. Between the years 1996 and 2016, the eastern gorilla reduced in numbers by over 70% and by 2016, the total population was predictable around less than 6,000. An exemption to this abating development is the mountain gorilla. Basing to the most latest approximations, there are roughly 1,004 mountain gorillas, and their numbers continue to grow steadily.

In some national parks, trekking mountain gorillas is a widespread tourist activity. The gorilla national parks comprise of Volcanoes National Park in Rwanda, Virunga National Park in the Democratic Republic of the Congo plus Mgahinga Gorilla National Park and Bwindi Impenetrable National Park in Uganda. Whereas ecotourism can advantage gorilla populations by making revenue for conservation efforts, there is worry that continued exposure to human beings will put gorillas at bigger threat of contracting zoonotic sicknesses. Researches have revealed that habituated eastern gorillas, mainly those that leave conservation zones to search for food in neighboring societies, have upper disease rates compared to their unhabituated equivalents, with proximate humans and livestock as the probable bases of spread.

Unlike the western gorilla, there are few eastern gorillas living in the zoos. The Antwerp Zoo is the only zoological confinement place outside the native range of the species that has eastern gorillas. Outside the natural range, the mountain gorilla is not at all held in detention. Small groups comprising of faunas repossessed from rustlers are reserved in the Democratic Republic of Congo.