Black capuchin

The black capuchin is found in the Atlantic region of North-eastern Argentina and South-eastern Brazil, with its habitat overlapping with other capuchin species. They are considered arboreal, mainly dwelling in the tree canopy; however, they will also drop to the forest floor to forage, where insects and nuts are most abundant.

Females strongly favor the alpha male in choosing a sexual partner; one study found that he is the target mate in three-quarters of female sexual advances and failed to find any coercion on his part which might force this outcome. To initiate mating, females possess a wide variety of signals, both auditory and ocular, which they employ at different stages of the process. There is some evidence that these are used to encourage coitus to occur at the time most opportune for procreation, including the increasing frequency with which visual signals occur as ovulation approaches. At least seven distinct calls exist for this purpose alone, although no evidence has been found that call type indicates anything to do with the stage of ovulation or fertility, although they do change pre and post-copulation. Those vocalized after mating may function to assure the chosen mate of his paternity by making the whole affair public knowledge, thereby encouraging him to guard both the female and her resulting offspring from competing mates and infanticide. In this context, the purpose of male postcoital courtship is perhaps revealed to be mate protection. For the same ends, the potentially impregnated female might use visual signals to assure the alpha of his status as her mate, while using vocalizations to confuse the other males as to who the father truly is, thereby discouraging aggression.