For years the world's largest primate has been portrayed as a fearsome and aggressive beast. But gorillas are actually gentle giants, who have strong family ties and live on a vegetarian diet.

Subspecies
Three subspecies: Gorilla berengei berengei (mountain gorilla), G. berengei ? (subspecies name unclassified) (Bwindi gorilla), G. beringei graueri (eastern lowland gorilla),

Life span
50 years.

Statistics
Males measure 170-180cm and weigh 140-275kg. Females measure 140-150cm and weigh 60-100kg.

Physical description
Gorillas have short legs, long muscular arms, a wide chest, a large head and large canine teeth. The hands are broad with short digits. The body is covered with coarse black hair, which in mature males goes grey, earning them the name silverback.

Distribution
Mountain gorillas live in the Virunga Volcano region of Uganda, Rwanda and the Democratic Republic of Congo. Bwindi gorillas inhabit Bwindi Impenetrable National Park, Uganda. Grauer's gorillas inhabit eastern Democratic Republic of Congo.

Habitat
Mountain gorillas inhabit mountain cloud forest up to 3,000m, where temperatures can be sub-freezing at night. Eastern lowland gorillas live in the lower altitudes up to 2,255m.

Diet
Gorillas mainly feed on leaves, but they also consume fruit, seeds, flowers, roots, herbs, insects and clay.

Behaviour
Gorillas form relatively stable, mixed-sex groups. Solitary animals, (usually fully adult males), make up approximately 10 per cent of the population. They are diurnal and mainly terrestrial. Gorillas tend to move across the forest floor on their knuckles, and they are capable of moving bipedally. They make a new sleeping nest every night.

Reproduction
Gorillas give birth to one young (very rarely, twins) after a gestation period of 251-289 days. The young weigh 2kg at birth.

Conservation status
The entire population of gorillas is seriously threatened due to the destruction of their habitat and by trophy/meat hunting. Overall there are probably fewer than 100,000 gorillas left in the world, including 320 mountain gorillas, 300 Bwindi gorillas and 8,000 eastern lowland gorillas.