Mountain Gorillas live in families called troops. A dominant adult silverback male that is typically more than 12 years of age, heads the troop of multiple adult females and male with their offspring.
Troops are formed when both males and females emigrate from their natural groups. This dispersal is more common in females than males.
The Troops established divide further more .Mature males tend to also leave their troops or families and establish new troops by attracting emigrating females. However, male mountain gorillas sometimes stay in their natal troop and become subordinate to the silverback. They may gain the opportunity to mate with new females or become dominant if the silverback dies.
In a single male group, when the silverback dies, the females and their offspring disperse and find a new troop. Without a silverback to protect them, the infants will likely fall victim to infanticide, and searching out and joining a new group is likely to be a tactic against this.