Preferences of female American goldfinches (Carduelis tristis) for natural and artificial male traits

We conducted two experiments to determine mating preferencesof female American goldfinches (Carduelis tristis). In the firstexperiment, females were allowed to choose among four naturallyvarying males. In the second, females chose among four maleswearing either orange, blue, yellow, or no color bands. In experiment1, females performed more courtship with males that had significantlybrighter bills and were brighter overall. In experiment 2, femalespreferred males wearing orange bands over unhanded males. Blue-bandedmales ranked second and yellow third, but neither was preferredsignificantly more often than the unbanded males. A female'spreference for a particular band color was weakly associatedwith her own bill and plumage measures; females with brighterthroat feathers and yellower bills preferred orange bands toblue bands. The results suggest that female preferences fororange and yellow may be functional and that females may alsohave aesthetic preferences.