Alpine Accentor (Prunella collaris) Science Article 3
Alpine accentors and dunnocks bred in polygynandrous groups in which two or moreunrelated males shared two or more females. In both species, a female solicited actively to both alphaand subordinate males whereas an alpha male attempted to guard the female to monopolize paternity.Females combated the restrictions imposed by alpha male guarding by increasing their solicitation rateto males who had gained less mating access. Males increased their copulation rate in response, but alphamales ignored more of the oVers. In both species, even when a female mated with both alpha and betamales she often gained just one male’s help with chick feeding. Under these conditions, alpha malealpine accentors reduced their amount of help with a decreased mating share, whereas beta males didnot. In dunnocks, however, neither alpha nor beta males reduced their help provided a critical share ofthe matings was exceeded. As predicted if females attempted to maximize male help, female alpineaccentors preferred to give more matings to the alpha male while female dunnocks preferred alpha andbeta equally. There was no evidence for either species that alpha males sired fitter oVspring; withinbroods of mixed paternity, there was no diVerence in the weights of chicks sired by alpha versussubordinate males. Female dunnocks competed with other females by territory defence whereas femalealpine accentors had overlapping ranges and competed directly for male attention, increasing theirsolicitation rate to the alpha male if other females in the group were fertile. We suggest that theextraordinarily high rates of solicitation by females, refusal by males and copulation rates (up to athousand per clutch) in the two species are the outcome of sexual conflict over the control of mating.
N. B. Davies, I. R. Hartley, B. J. Hatchwell & N. E. Langmore, Anim. Behav., 1996, 51, 27-47