MANIPULATING A SEEMINGLY NONPREFERRED MALE ORNAMENT REVEALS A ROLE INFEMALE CHOICE

Past studies of a feral South African population of guppies have shown that females use the area of orange coloration borne by males as a cr iterion for mate choice. However, males bear spots of other colours, t he most noticeable of which is black. We investigate whether female pr eference can maintain the black spots of male guppies despite the appa rent unimportance of black to female choice in correlative studies. Wh en part of a male's black pigmentation is removed, his 'attractiveness ' to females decreases. This supports the hypothesis that in male anim als with several ornaments, seemingly non-preferred ornaments can be m aintained by female choice. These findings are discussed in the contex t of several models which account for the evolution of multiple male o rnaments.