Until recently there were considered to be three species of gorilla, The Western Lowland, The Eastern Lowland and Mountain Gorilla. There is now agreement that the gorilla is divided into two species of at least two subspecies each. More recently it has been claimed that a third subspecies exists in one of these groups.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. Black backs 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.