group for the majority of their lives. Males generally leave their natal group between 3 and 6 years of age. Young males spend little time alone after leaving their natal groups and quickly integrate into a new group. Males prefer to join groups with a high ratio of females to adult males, as this maximizes their probability for future mating success. Immigrating males generally meet little opposition when joining a new group. Older females may migrate to new groups on rare occasions. Infanticide Infanticide, or the deliberate killing of an infant, in any non-human primate is of considerable interest to ecologists because it can affect the particular primate's reproductive success and ultimately lead to great demographic changes within the primate's troop. Infanticide has been observed in C. olivaceus. Genetically, it may pay for a male wedge-capped capuchin to kill an unrelated newborn, so that he can then mate with the mother sooner than if the baby was still alive. This allows the male to propagate his genes faster through the troop. However, in Valderrama's research, the infanticidal male gained reproductive success from the killing in only one of the three cases studied. High-ranking females' infants were targeted in all three cases. The variability surrounding the infanticide among the three cases studied is characteristic surrounding infanticide among any other non-human primates. Dominance hierarchy Both male and female wedge-capped capuchins have a dominance hierarchy. Female status is often established based on matrilines, with dominant mothers tending to have dominant daughters. Male dominance is not as easily passed from one generation to the next due to male migration. This dominance hierarchy is particularly helpful in explaining female-initiated agonistic behavior. Females higher in the hierarchy tend to be more aggressive toward both females and males that are lower on their respective dominance hierarchies. Aggressive behavior includes lunging, vocalization, and chasing. Sometimes many females chase males together. Male aggression was not correlated with position in the dominance hierarchy. Male aggression toward females is generally limited to vocalizations, lunging, and chasing. On one occasion, however, an adult male was observed to attack and kill a young adult female from the same group. This level of aggression is not the norm, usually being practiced in the animal kingdom as a method of takeover. Grooming Grooming behavior plays an important role in the group dynamics of wedge-capped capuchins. Grooming may be a way for both sub-adult males and