Male silverback mountain gorillas gain their distinctive silver tinge at about 13 years old, when they reach adulthood. Size relative to a 6-ft (2-m) man: There are roughly 700 mountain gorillas remaining on Earth, and nearly half live in the forests of the Virunga mountains in central Africa.
Gorillas can climb trees, but are usually found on the ground in communities of up to 30 individuals. These troops are organized according to fascinating social structures.