Does more choice equal a better choice? Courtship behavior, mating propensity and female fitness in relation to the number and density of potential partners

The good genes hypothesis predicts that females discriminate among potential mates on the basis of their genetic quality. We measured the indirect benefits received by females with different levels of choice---from no choice to choosing among 5 males---in the housefly, Musca domestica , at high and low density. Secondly, we tested how the degree of choice affected the courtship behavior of both sexes and whether this behavior was correlated to female reproductive success. Opportunity for choice did not affect mating propensity or offspring survivorship, but did affect male courtship rate and the number of eggs females laid in their first clutch. Females at low density were more likely to mate, laid more eggs in their first clutches, and had greater egg-to-adult viability than females mated at high density. Overall, the degree of choice affected some aspects of mating behavior and fitness, but the effects were primarily density dependent