FOOD PROVISIONING IN THE PIED FLYCATCHER - DO FEMALES GAIN DIRECT BENEFITS FROM CHOOSING BRIGHT-COLORED MALES

1. We studied individual variation in the performance of parental care of male pied flycatchers Ficedula hypoleuca in a woodland area near O slo, Norway. 2. During a 24-h period of enforced female absence, we re corded male feeding rate and nestling growth, as well as changes in ma le body mass. 3. Using a matched-pairs comparison we found that older males were more successful in feeding the young than 1-year-old males, even when plumage colour or breeding experience were similar. These r esults may be explained by increased skill due to age or condition-dep endent mortality, rather than increased parental effort, since young a nd old makes lost equal body mass during the period of female absence. 4. Overall, bright-coloured males and males with previous breeding ex perience performed better in terms of increased brood mass, than dull- coloured males and males without previous breeding experience, respect ively. These results were not significant when we only compared males of similar age, but the sample sizes were small in the latter comparis ons. 5. Bright-coloured males also tended to lose less body mass when they were left to feed the brood alone than did dull-coloured males, i ndicating that the higher performance was not due to a higher parental expenditure. 6. We argue that females that choose old males as mates benefit in terms of a mate that is capable of a higher performance of parental care. Females may use male plumage colour as an indirect cue in assessing male age, since the plumage becomes brighter with age. 7. Despite differences in brood-mass changes during female absence, ther e was no difference in feeding rate between first-year and older males , nor between dull- and bright-coloured males. This shows that feeding rate may be an inadequate measure of the variation in individual abil ity to nourish the young.