The polyandrous groups consist of a single reproducing female and several sexually active males. In these groups, several of the males usually participate in the care of offspring. Many primate species live in groups consisting of a single adult male along with several females and their offspring. The one-male groups are almost invariably characterized by repeated efforts by outside males to takeover the position of the resident male. In many instances, dependent infants are killed as a result of a change in the status of a resident male.
Competition is high in the one-male society.
Another type of social grouping among primates is the multimale group. Such groups are characterized by complex intratroop politics and competition. These groups tend to become relatively large in size with several males and numerous females and offspring. Among the Gombe Stream chimpanzees that Jane Goodall has studied is still another form of primate society known as fission-fusion. Yet, the group as a whole tends to reunite in the ebb and flow of changing activities.