Grauer’s gorilla silverbacks (mature males) can tip the scale at over 225kg (about 500lb) and are several times stronger than a human.
Although gorillas are capable of fearsome displays of strength and aggression, beating their chests, hooting, charging and fighting, the great apes’ society is essentially very peaceful.
The primates mainly feed on vegetation and fruit, and occasionally insects. Grauer’s gorilla families are usually formed of groups of females and youngsters, led by a single dominant silverback.
Significantly less is known about Grauer’s gorillas compared with their close relative, the mountain gorilla, and it is not known exactly how many are left in the wild.
However it is thought their numbers have dramatically declined in recent decades largely due to hunting, capture and habitat destruction, threats which escalated during DR Congo’s civil war.
A large team of trackers and guards protect gorilla families from poachers in the Kahuzi-Biega National Park.
Some experts believe eco-tourism is the best or even only hope for the future survival of Grauer’s gorillas in the wild.
Some of the gorillas in Kahuzi-Biega National Park are already habituated to humans, while rangers are working with others to get them used to people’s presence.
‘Gorilla Family & Me’ begins in the UK on BBC Two, Monday 21 December at 21:00 GMT.