About the silver back gorillas in Rwanda
A silverback is an adult male gorilla, typically more than 12 years of age and named for the distinctive patch of silver hair on his back. A silverback gorilla has large canines that come with maturity. Blackbacks are sexually mature males of up to 11 years of age. Silverbacks are the strong, dominant troop leaders.
Each typically leads a troop of 5 to 30 gorillas and is the center of the troop’s attention, making all the decisions, mediating conflicts, determining the movements of the group, leading the others to feeding sites and taking responsibility for the safety and well-being of the troop.
Males will slowly begin to leave their original troop when they are about 11 years old, travelling alone or with a group of other males for 2–5 years before being able to attract females to form a new group and start breeding. While infant gorillas normally stay with their mother for 3–4 years, silverbacks will care for weaned young orphans.
If challenged by a younger or even by an outsider male, a silverback will scream, beat his chest, break branches, bare his teeth, then charge forward. Sometimes a younger male in the group can take over leadership from an old male. If the leader is killed by disease, accident, fighting or poachers, the group will split up, as animals disperse to look for a new protective male. Very occasionally, a group might be taken over in its entirety by another male. There is a strong risk that the new male may kill the infants of the dead silverback.