Reproductive Value and Rank Relations Among Macaque Sisters

Abstract

The ontogeny of social dominance relations among female macaques follows a highly predictable sequence. Females rank just below their mothers. By the time a female attains 4 yr of age, she surpasses older sisters in rank. As adults, rank among sisters is inversely correlated with age. Such regularity cannot be attributed to phenotypic differences in individual prowess. Asymmetries in the network of agonistic support may confer rank and the inverse correlation of rank with age among adult sisters may in part be due to mothers favoring daughters with the highest reproductive value which are always the youngest among adult daughters. Reproductive values are computed from a macaque life table and the predictions of this model were discussed with respect to existing data on the allocation of parental investment and the generated reproductive value curve.