Social structure

Gorillas live in groups called troops. Troops tend to be made of one adult male or silverback, multiple adult females and their offspring.[43][44][45] However, multiple-male troops also exist.[44] A silverback is typically more than 12 years of age, and is named for the

distinctive patch of silver hair on his back, which comes with maturity. Silverbacks also have large canine teeth that also come with maturity. Both males and females tend to emigrate from their natal groups. For mountain gorillas, females disperse from their natal troops more than males.[43][46] Mountain gorillas and western lowland gorillas also commonly transfer to second new groups.[43]

Mature males also tend to leave their groups and establish their own troops by attracting emigrating females. However, male mountain gorillas sometimes stay in their natal troops and become subordinate to the silverback. If the silverback dies, these males may be able

to become dominant or mate with the females. This behaviour has not been observed in eastern lowland gorillas. In a single male group, when the silverback dies, the females and their offspring disperse and find a new troop.[46][47] Without a silverback to protect them, the infants will likely fall victim to infanticide. Joining a new group is likely to be a tactic against this.[46][48]

However, while gorilla troops usually disband after the silverback dies, female eastern lowlands gorillas and their offspring have been recorded staying together until a new silverback transfers into the group. This likely serves as protection from leopards.[47]