the areas of their partner which their partner cannot groom themselves. Grooming, however, also serves several social functions, all associated with bonding. For example, it allows for low-rank black capuchins to bond with the dominant members of the group and for members at odds with each other to reconcile and relieve tension. The purpose of such bonding is often for lower ranked monkeys to procure easier food access from dominant bond-partners. Females, for example, might compete to groom the dominant female in those cases where a hierarchy exists, which is not assured among female black capuchins. Still, same sex grooming is rare, however, with little to no evidence of male-male grooming and female-female grooming accounting for a minority of cases. Female-female grooming only occurs when the group is highly cohesive. When it does occur, they favour kin. Females more commonly bond with males, particularly the alpha. The hierarchy has other effects on grooming as well. For one, face to face grooming is more frequent when the groomer is dominant and well-bonded with partner being groomed. The frequency increases even more based on rank-difference; the less equal the monkeys’ footing in the above described situation, the more likely face to face grooming is. Reproduction Females strongly favour 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 at 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 and thereby encourage 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