Female feral fowl eject sperm of subdominant males

Paternity is often determined by competition between the ejaculates of diff erent males(1). Males can also use particular behaviours or structures to m anipulate how females use sperm(2-5). However, the ability of females to bi as sperm utilization in favour of preferred males independently of male man ipulation has not been demonstrated(6). Females are predicted to respond di fferentially to the sperm of different males when the reproductive interest s of the sexes differ and when females are coerced into copulating(4,6). He re we show that in female feral fowl most copulations are coerced, and that females consistently bias sperm retention in favour of the preferred male phenotype. Females prefer to copulate with dominant males, but when sexuall y coerced by subordinate males, they manipulate the behaviour of dominant m ales to reduce the likelihood of insemination. If this fails, females diffe rentially eject ejaculates according to male status in the absence of any m ale manipulation and preferentially retain the sperm of dominant males.