FEMALE ZEBRA FINCHES PREFER MALES WITH SYMMETRICAL CHEST PLUMAGE

The level of fluctuating asymmetry in a secondary sexual character is believed to reveal aspects of male quality. Previous investigations have demonstrated that females may pay attention to this information when making mate choice decisions; females prefer symmetric over asymmetric males. However, these studies have involved either manipulation of functionally important flight feathers, or of artificial ornaments. Here, we manipulate an existing secondary sexual plumage trait, one that does not influence flight performance, within the boundaries of natural asymmetry. Through manipulations of chest plumage, we demonstrate that female zebra finches choose to display more and for longer in front of males with symmetric, as opposed to asymmetric, chest plumage.