Do female zebra finches vary primary reproductive effort in relation to mate attractiveness?

Female choice and mate preference have been shown to affect female reproductive effort both prior to copulation (e.g. females seeking extra-pair copulation) and during parental care ('secondary' reproductive effort) in relation to mate quality. Here we show that female zebra finches, Taeniopygia guttata, vary their 'primary' reproductive effort in egg production in relation to the attractiveness of their male partner, for some components of reproduction but not others. Females were allowed to choose 'preferred' and 'non-preferred' males in standard mate choice trials, and were then paired sequentially with each male. Preferred males had significantly higher song duration and song frequency than non-preferred males confirming that females preferred attractive, higher quality males. Male attractiveness had a positive, but weak, effect on clutch size: in breeding experiments individual females laid on average 0.5 eggs more when paired with their preferred male compared to the non-preferred male. However, there was no significant difference in breeding propensity (whether females laid eggs or not), number of days between pairing and laying, mean egg size or egg quality (protein and lipid composition) in relation to male type. These results suggest that components of primary reproductive effort in individual female zebra finches are relatively non-plastic traits.