Gorillas - Life in a Family

Gorillas live in groups. As a rule, the groups consist of one adult male, several females and their offspring. One way such a harem group starts is by a female transferring from her natal group to a lone male. Growing offspring of either sex usually leave their natal group. Females always join another group or a lone male, whereas male gorillas usually turn into loners.
In males, the separation process is slow: they spend more and more time on the edge of the group until they leave altogether. In contrast, a female leaves her group only if she encounters another male. The home ranges of various gorilla groups and of lone silverback males overlap, so encounters are frequent. Lone males often make a special effort to seek out harem groups out, as this is their only chance to gain females. The leaders of stable harem groups avoid contact with other adult males in order to avoid losing females. If they detect a competitor, they try to drive him away by displaying or attacking.

Infant Development - Puberty - Groups - Fighting Silverbacks - References