Updated
Gorillas are highly intelligent. In the wild, mountain gorillas use complex, learned techniques to process difficult foods such as stinging nettles and thistles, remember the locations of seasonal foods across large ranges, and navigate complicated social relationships. Tool use is rarer than in chimpanzees, because gorillas seldom need it, but wild western gorillas have been seen using sticks to test water depth. In captivity, gorillas have learned hundreds of signs and solved puzzles, though how far this reflects language is debated.
Clever feeding
Research on mountain gorillas in the Virungas showed that they use multi-step techniques to eat plants defended by stings, spines or hard casings: folding nettle leaves so the stinging hairs are inside, stripping thistle stems, or peeling bamboo shoots. Youngsters learn these skills over years by watching and practising, and individuals develop their own variations. This kind of planned, sequential handling is considered a sign of advanced cognition. See our guide to what gorillas eat in their habitat.
Tool use and problem-solving
The first published records of tool use by wild gorillas, in 2005, described western lowland gorillas in the Republic of Congo using a branch to test the depth of a swamp before wading, and using a trunk as a support. Mountain gorillas rarely use tools, probably because their foods do not require them. Trackers in Rwanda have reported young gorillas pulling apart snares, though this is anecdotal. Captive gorillas readily solve puzzles, use tools and learn from people. See our guide to how gorillas communicate.
Social intelligence and language
Gorillas track relationships, alliances and status within their group, and silverbacks mediate disputes. Koko, a captive gorilla in California, was taught a version of sign language and was reported to use over a thousand signs, though scientists disagree about whether she used language in the human sense. Gorillas share about 98% of their DNA with humans. See our guides to Koko and gorillas in popular culture and gorilla DNA.
Seeing it on a trek
During your hour with a family, watch how gorillas handle food, how infants copy adults, and how the silverback keeps order with a glance or a grunt. The gorilla permit costs US$800, or US$600 in April, May and November.
Frequently asked questions
Yes; they show complex learned skills, memory and social understanding.
Rarely; wild western gorillas have been seen using sticks to test water depth.
She used many signs, but scientists debate whether it was language.
They fold the leaves so the stinging hairs are inside before eating.
