The Mountain Gorilla (Gorilla beringei beringei) is one of the two subspecies of the Eastern Gorilla. There are two populations. One is found in the Virunga volcanic mountains of Central Africa, within three national parks: Mgahinga, in south-west Uganda; Volcanoes, in north-west Rwanda; and Virunga in the eastern Democratic Republic of Congo (DRC). The other is found in Uganda’s Bwindi Impenetrable National Park.

The Mountain Gorilla is primarily an herbivore; the majority of its diet is composed of the leaves, shoots and stems.The Mountain Gorilla is highly social, and lives in relatively stable, cohesive groups held together by long-term bonds between adult males and females. Relationships among females are relatively weak. These groups are nonterritorial,the silverback generally defends his group rather than his territory. In the Virunga Mountain Gorillas, the average length of tenure for a dominant silverback is 4.7 years.

Most males, and about 60% of females, leave their natal group. Males leave when they are about 11 years old, and often the separation process is slow: they spend more and more time on the edge of the group until they leave altogether.When the dominant silverback dies or is killed by disease, accident, or poachers, the family group may be severely disrupted.Unless he leaves behind a male descendant capable of taking over his position, the group will either split up or be taken over in its entirety by an unrelated male.

This is an abridged version of the article at http://en.wikipedia.org/wiki/Mountain_Gorilla