Male Ranking Order and Copulation Frequency in the E1 Group of Bonobos, at Wamba, Zaire

Abstract

1. Among the bonobos in the Wamba forest, central Zaire, male mating frequency was not strongly linked with his dominance rank. However, his mating rate (number of copulations per hour) was positively correlated with his rank.2. Three types of male dominance rank were taken into consideration, namely, rank within the group, party and patch. In bonobos at Wamba, males dramatically increased their temporary ranks (i. e., rank within a patch) by placing themselves opportunistically within the party space, and adult males in particular performed the majority of their copulations when they were the first ranking male within such a patch.3. One case was observed in which there was a “sneaky” sexual solicitation by a male which corresponds to the “leaf clipping” display of Mahale chimpanzees.4. It was concluded from 1, 2, and 3 that sexual competition among male bonobos at Wamba is more intense than has been thought, though other factors, especially the mother-son bond will influence males' mating success as well.