FEMALE CONTROL OF COPULATIONS TO MAXIMIZE MALE HELP - A COMPARISON OFPOLYGYNANDROUS ALPINE ACCENTORS, PRUNELLA-COLLARIS, AND DUNNOCKS, PRUNELLA-MODULARIS

Alpine accentors and dunnocks bred in polygynandrous groups in which t wo or more unrelated males shared two or more females. In both species , a female solicited actively to both alpha and subordinate males wher eas an alpha male attempted to guard the female to monopolize paternit y. Females combated the restrictions imposed by alpha mate guarding by increasing their solicitation rate to males who had gained less matin g access. Males increased their copulation rate in response, but alpha males ignored more of the offers. In both species, even when a female mated with both alpha and beta males she often gained just one male's help with chick feeding. Under these conditions, alpha male alpine ac centors reduced their amount of help with a decreased mating share, wh ereas beta males did not. In dunnocks, however, neither alpha nor beta males reduced their help provided a critical share of the matings was exceeded. As predicted if females attempted to maximize male help, fe male alpine accentors preferred to give more matings to the alpha male while female dunnocks preferred alpha and beta equally. There was no evidence for either species that alpha males sired fitter offspring; w ithin broods of mixed paternity, there was no difference in the weight s of chicks sired by alpha versus subordinate males. Female dunnocks c ompeted with other females by territory defence whereas female alpine accentors had overlapping ranges and competed directly for male attent ion, increasing their solicitation rate to the alpha male if other fem ales in the group were fertile. We suggest that the extraordinarily hi gh rates of solicitation by females, refusal by males and copulation r ates (up to a thousand per clutch) in the two species are the outcome of sexual conflict over the control of mating. (C) 1996 The Associatio n for the Study of Animal Behaviour