The Influence of Kinship, Rank, and Sex On Affiliation and Aggression Between Adult Female and Immature Bonnet Macaques (Macaca Radiata)

Abstract

Kinship, rank, and sex have complex and variable influences upon the relationships of adult females and immature bonnet macaques. Affiliative behavior by adult females toward immatures is based largely upon kinship as females groom related immatures at higher rates than the offspring of unrelated females. Although females are groomed by their immature kin at higher rates than by the daughters of higher ranking females (HRF's) or the sons ofHRF's, females are groomed by their immature female kin and the daughters of lower ranking females (LRF's) at similar rates. Thus, both kinship and female rank influence rates of grooming by immature females. The extent of the contribution made by adult females and immatures to their mutual grooming relationship varies. All adult females groom their immature male kin and the daughters of HRF's more than they are groomed by them, and are groomed by the daughters of LRF's more often than they groom them in return. The extent of the contribution which females make toward their grooming relations with immature female relatives and the daughters of HRF's is correlated with their rank such that low ranking females contribute more to their relationships with these immatures than high ranking females do. Females harass (threaten, displace, chase, and attack) the offspring of relatives and HRF's at similar rates. Immature females receive more aggression from unrelated females and are injured at higher rates than are immature males of the same maternal rank. Although rates of aggression toward related immatures and the offspring of HRF's do not differ consistently, severe forms of aggression are primarily directed toward nonrelatives. These results are interpreted with reference to kin selection, local resource competition, and sex-specific differences in the life histories of males and females.