- English – Eastern Lowland Gorilla, Grauer’s Gorilla
- French – Gorille de plaine de l’Est, Gorille de Grauer
- German – Grauer-Gorilla
- Spanish - Gorila de Grauer
The Eastern Lowland Gorilla (Gorilla beringei graueri) is a subspecies of gorillas, together with the endangered mountain gorillas and the Western lowland gorillas (Gorilla gorilla gorilla). The western lowland gorillas are not considered endangered species, being present in African countries like Congo-Brazzaville, Central African Republic, Equatorial Guinea, Cameroon, Gabon and Congo.
The Eastern lowland gorillas are endangered and they are found specifically in Kahuzi Biega National Park and Maiko National Park in the Democratic Republic of Congo. They live in heavy rain forests, and it is difficult for scientists to accurately estimate how many survive today. The Eastern Gorilla tends to be larger in size than the Western. Differences between the two species include: longer, blacker hair for the Eastern; the head hair tends not to have red-chestnut tones as is usually the case with adult Western males.
Eastern Lowland Gorillas tend to be sociable and very peaceful, living in groups of 5 to 30. A group usually consists of one silverback and few subdominant males. Silverbacks are the strong, dominant troop leader’s .They are in charge of leading the group to food and protecting the group from danger. Males will slowly begin to leave their original group when they reach maturity, usually traveling with a group of other males for a few years before being able to attract females to form a new group.
The leader organizes troop activities like eating, nesting in leaves, and moving about the group's home range. They eat roots, shoots, fruit, wild celery, and tree bark and pulp, as well as ants, termites and other insects. When fruit is scarce, Eastern Lowland Gorillas travel less and increase their consumption of herbaceous vegetation. They follow seasonal eating behavior.
Female gorillas give birth to one infant after a pregnancy of nearly nine months. Unlike their powerful parents, newborns are tiny—weighing four pounds (two kilograms)—and able only to cling to their mothers' fur. These infants ride on their mothers' backs from the age of four months through the first two or three. Young gorillas, from three to six years old, remind human observers of children. Much of their day is spent in play, climbing trees, chasing one another, and swinging from branches.
In the wild, these primates are under siege. Forest loss is a twofold threat; it destroys gorilla habitat and brings hungry people who hunt gorillas for bush meat. Farming, grazing, and expanding human settlements are also shrinking the lowland gorillas’ space.
The Eastern Lowland Gorilla occurs only in eastern DRC, between the Lualaba river and the Burundi-Rwanda-Uganda border. Its distribution is limited to an area of about 90,000 km², within which it is thought to occupy an estimated 21,600 km² in five regions.
The trekking to see the Eastern lowland gorillas is open in the protected area of Kahuzi Biega National Park. In 2010 there are three habituated families, Chimanuka, Mankoto and Mugaruka. With ten families of gorillas remaining in the park area, the estimated number of gorillas today is 140 individuals only. A previous survey conducted in 1992 was showing the presence of 25 families with a total number of 284 individuals. The political turmoil which followed during the 90th and till recent time has affected much the conservation of the species.