Eastern Lowland Gorilla
Ecology
Physical Description
© Martin HARVEY / WWF-Canon
The eastern lowland gorilla is the largest of the gorilla subspecies. Its hair and teeth are shorter than the mountain gorilla's and its arms are longer. This impressive animal is identified by a stocky body, large hands and a short muzzle. Their hands include thumbs larger than the fingers. The face, ears, hands and feet do not have hair and older males do not have hair on their chest.
Diet
Eastern lowland gorillas are mainly herbivorous; their staple foods are pith, shoots and leaves. Fruits are also an important component of their diet based on seasonal availability. In drier months, when fruits are scarcer, gorillas supplement their diet with leaves, bark and rotten wood. The consumption of invertebrates, mainly termites and weaver ants is frequent, although it varies significantly across sites.
Reproduction
Females become sexually mature at 7-8 years old but do not start to breed until several years later. Males mature later than females with few breeding before the age of 15 years.
High infant mortality, a long gestation (eight and a half months), a tendency for single births and a prolonged period of maternal care mean that on average only one infant is reared in a 4 to 6 year period. Females generally give birth to only 3-4 surviving young during their reproductive life.
Social Structure
The eastern lowland gorilla’s name is misleading because it is not only found in the ‘low lands’ at the base of mountains. This species can live in high altitudes as well.
Gorillas have a well-developed social structure, living and traveling in family groups which vary from 2 to over 50 individuals, but more frequently include 5 to 10 individuals. Gorillas form stable groups with the dominant male keeping his position for years. If a male leaves a group he wanders alone for a number of years and sometimes establishes a range adjacent to or overlapping that of the former group.
Adult males that stay in a group are generally the offspring of the dominant male and eventually will take over leadership of the group. As a general rule female gorillas leave their natal group at maturity to join other groups or single males, although cases of females reproducing in their natal groups are known.
