THE relationship between dominance and reproductive success has been of considerable theoretical interest, with an extensive literature reporting its existence among males in many species1. Although female dominance hierarchies are known to exist in various species, the possibility of a similar relationship for females has not been investigated in detail. Indeed it is often assumed that Bateman's principle2 implies that intrasexual selection (and hence the effectiveness of dominance as a reproductive strategy) will be very much reduced among females. Only one study of mammals presents unequivocal evidence of a relationship between dominance and reproductive success for females3, although there is indirect evidence that it may occur in several other species4-7. We report here evidence for such a relationship in the case of female gelada baboons (Theropithecus gelada) in the wild.