Dominance and reproductive success in primates

Theoretical models of the relationship between competition and differential reproduction in primates share the premise that agonistic dominance hierarchies determine differential access to those limited resources which are essential to reproduction. In particular, the priority-of-access-to-estrous-female model is based on the postulate that high rank in males enhances reproductive success. Tests for a correlation between rank and reproductive success in males have produced mixed results. Problems in measuring male reproductive success and in conceptualizing dominance systems are implicated in the diversity of conclusions reached. Other attributes which affect reproductive success have been proposed, and alternative models of mating systems, based on the concepts of reproductive strategies, social skills, and life histories have also been developed. Studies of differential reproduction in female primates are fewer, but have the advantage over male studies of directly measuring infant production and offspring survival. Research on the relationship between rank and reproductive success in females has shown that under conditions of low resource availability, subordinate females sometimes suffer reduced fecundity and infant survival as a result of restricted access to food and water. Under conditions of social stress, low-ranking females may suffer from disruption of their reproductive cycles, resulting in lowered fecundity. Dominant females may also incur reproductive costs as well as benefits for their social position. Better insights into the relationship between dominance and reproduction are potentially offered by improved genetic paternity measures, new models of social and demographic processes, and the recent availability of life history data from field studies.