CORRELATES OF EXTRA-PAIR FERTILIZATION SUCCESS IN HOODED WARBLERS

We examined correlates of extra-pair fertilization (EPF) success in th e hooded warbler (Wilsonia citrina), a species where females pursue ex tra-pair matings. The good genes hypothesis predicts that females choo se extra-pair mates with morphological or behavioral traits that refle ct differences in male genetic quality. EPFs were common, as 35.3% (42 /119) of broods contained extra-pair young (EPY) and 26.7% (95/356) of nestlings were the result of EPFs. There was a strong skew in male EP F success which increased the variance in annual male mating success 2 -3 fold. However, male morphology did not predict EPF success, as extr a-pair males were not older or larger than the males they cuckolded. L ikewise, there were no significant correlations between the proportion of extra-pair young in a brood and male size or age. The good genes h ypothesis predicts that high-duality males will be consistently prefer red as genetic mates, but the number of young sired by a male with his social mate was not consistent from one year to the next, There was a significant negative correlation between female age and proportion of EPY produced, which could result if older females obtain higher-quali ty social mates. We found no strong evidence that females choose extra -pair mates for good genes, but females may use behavioral rather than morphological cues to assess relative male quality.