Alcohol Alters Female Sexual Behaviour

Consuming alcohol can influence sexual decision-making, but potential effects on female mating-behaviours like mate-choice are unclear. If alcohol alters female mate-choice then its consumption will affect sexual selection, a major mechanism of organic evolution. Here, we tested whether alcohol intake affected female mate preferences, choosiness and copulation duration using the fly Drosophila simulans as a model, while simultaneously testing for genetic variation in possible effects. We found that alcohol intake did not affect copulation duration, but did reduce female choosiness and weakened the strength of mate preference, as females mated more quickly and with more males after consuming alcohol. Although female genotype significantly affected choosiness, the effects of alcohol were broadly consistent across genotypes. Thus alcohol consumption reduced female choosiness and weakened mate-preference, potentially reducing the strength of sexual selection.