Eastern lowland gorilla

Eastern lowland gorilla
Conservation status
Endangered (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Family:	Hominidae
Genus:	Gorilla
Species:	G. beringei
Subspecies:	G. b. graueri
Trinomial name
Gorilla beringei graueri (Matschie, 1914)

The eastern lowland gorilla (Gorilla beringei graueri) is a subspecies of eastern gorilla that is now only found in the forests of eastern Democratic Republic of the Congo. Many live within the boundaries of Kahuzi-Biega National Park.

This subspecies is considerably larger and more robust in appearance^{[citation needed]} than the western lowland gorilla, having a longer body, longer teeth, a stronger jaw and a broader torso. They have black coats which in males, like other gorillas, turns silver at the back as the animal matures. There are many more western lowland gorillas than the eastern variety; compared to a possible total of over 100,000 western lowland gorillas, there are only about 4,000 eastern lowland gorillas in the wild, and 24 in zoos.

Physical description

The eastern lowland gorilla is the largest subspecies of gorilla and the largest living primate. The maximum size of a male eastern lowland gorilla can be over 250 kilograms (550 lb) and when standing fully erect over 2 metres (6.6 ft) in the wild, with much heavier weights recorded in captivity. Some males are recorded to have weighed 275 kg (610 lb), 287 kg (630 lb), 312 kg (690 lb), 318 kg (700 lb) and 338 kg (750 lb).^{[citation needed]} The record weight belongs to a male named Phil, who weighed 388 kilograms (860 lb) and lived between 1941 and 1958 at the St. Louis Zoo. Phil's measurements were: height 1.7 metres (5.6 ft), bust 182 centimetres (72 in), neck 91.5 centimetres (36.0 in) and wrist 38 centimetres (15 in). He was weighed on a verified weight after an eight-week-long diet. According to the late John Aspinall, a 550 lb (250 kg) male eastern lowland gorilla in his prime has the combined strength of 7–8 heavyweight Olympic weightlifters.^{[citation needed]}

Habitat and ecology

Eastern lowland gorillas are predominantly herbivorous, eating mostly leaves. They are known to eat only a few leaves from a single plant, allowing the plant to regrow. They will also eat fruit, seeds, bamboo shoots and insects. Gorillas also engage in coprophagia, they eat their own feces, as well as the feces of other gorillas.^{[citation needed]} Similar behavior has also been observed among chimpanzees. Such behavior may serve to improve absorption of vitamins or of nutritive elements made available from the re-ingestion of seeds.

Male eastern lowland gorilla

Behaviour

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 leaders (see alpha male). 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.

Reproduction

A female will give birth to twins or a single infant after a gestation period of about 8½ months. They breastfeed for about 12 months. The baby can crawl at around 9 weeks old and can walk at about 35 weeks old. Infant gorillas normally stay with their mother for 3 to 4 years and mature at around 11 to 12 years old.

External links

• ARKive - images and movies of the eastern gorilla (Gorilla beringei)
• Eastern Lowland Gorilla Numbers Plunge to 5,000, Study Says National Geographic News, March 2004.