Summary: Clutton-Brock et al. (2006)

For most animals, competition is more intense in the sex that invests less in offspring. However, in some cooperatively breeding species, such as meerkats (Suricata suricatta), females (which normally invest more in care) compete more frequently and intensely. In the case of meerkats, a single dominant female will monopolise reproduction in a group. Clutton-Brock et al. (2006) showed that female meerkats gain greater reproductive benefits from acquiring dominance status and the traits that increase competitive ability also exerted a greater influence on breeding success. Individual differences in breeding success depend on the length of time the individual remains dominant in the group. Clutton-Brock et al. (2006) show that females that reach dominance status have longer breeding tenures and gain greater reproductive benefits than males. They suggest that the greater benefits accrued could explain why females compete so intensely for breeding opportunities. They suggest that the mechanism generating sex differences in reproductive competition in parental investment is not only related to sex differences in parental investment. They also suggest that competition for breeding opportunities influences the evolution of sex differences and how sexual selection operates.