The absence of a matrilineally based dominance system in sooty mangabeys, Cercocebus torquatus atys

Abstract

Abstract. Sooty mangabeys, Cercocebus torquatus atys, exhibit a dominance hierarchy that is unrelated to matrilineal kinship except during the first years of life. A cross-sectional analysis showed that young mangabeys, from infancy to approximately 3 years of age, rank just below their mothers, although thereafter generally attain higher rank than their mother. There is a sex difference in the rank animals eventually achieve. Although males and females generally begin to attain higher rank at about the same age, males between the ages of 5 and 6 years ultimately rank above all females. A multiple regression analysis showed that sex, age and maternal rank significantly predicted an individual's rank with a multiple correlation coefficient of 0·73. No relationship existed between dominance rank of adult females and age or weight. Moreover, no relationship was found between the rank of adult females and that of their younger adult sisters. Thus, these data demonstrate that the dominance system in this species initially depends upon maternal rank, then later upon sex and other unknown factors, a pattern which does not fit the Kawai and Kawamura model of inheritance of maternal dominance rank (1958, Primates, 1, 111-130, 149-156).