Editing Common patas monkey (section)

=== Male social organization ===
Mating in common patas monkeys is seasonal and occurs during the wet season.{{citation needed|date=February 2015}} During periods when females are not receptive, relatively stable groups with one adult resident male and several females are the norm. This leaves an excess of males that either form all male groups or live on their own. During the mating season, resident males may be chased away by invading solitary males. This usually results in the formation of multi-male, multi-female groups shortly thereafter, as more males invade a group. The new resident male does not chase away subordinate invading males, but rather focuses on mating with females. At the end of the mating season, one-male, multi-female groups stabilize. One male remains as the resident male and chases other males away. In some instances, submissive males are tolerated by the resident male for short periods of time; however, they rarely remain in the group for more than several days.{{sfn|Ohsawa|2003}}

Young males have been observed to leave their natal groups anywhere from two to four years of age. However, one study showed that most juveniles left before they were three, which is before most males reach sexual maturity. This contrasts with an earlier study in which juveniles were observed to leave later, at sexual maturity, indicating that there may be variation between groups. The reason young males leave their natal group is also contested. Dominant males have been observed to act aggressively toward younger males in captivity. However, observations of wild patas monkeys has shown young males leaving the group in which they were born without any aggressive behavior from the adult male. The juveniles, in the time shortly before they leave, spend increasingly less and less time with the adult females in the group. However, juvenile males do not change the amount of time they spend near the adult male. This may indicate weakening of matrilineal ties, rather than male aggression, as the main reason juveniles disperse from their natal group.{{sfn|Rogers|Chism|2009}}