Environment, competition and reproductive performance of female monkeys

In most wild and captive monkey groups, some females are clearly dominant over others. Dominant animals have priority of access to resources, and well fed animals generally outreproduce poorly fed ones. So why is it that only in some social groups are dominant female monkeys more fecund than subordinate ones? The distribution of food influences the intensity of competition between group members, and it appears that dominants do better only when interference competition is intense. In addition, dominance influences reproductive performance via reproductive parameters other than simple fecundity. Analysis of the different components of reproductive success, and of the environmental conditions under which dominants outreproduce subordinates, should help our understanding of the biological processes by which differential reproductive performance arises.