Novel mate preference through mate-choice copying in zebra finches: sexes differ

The development of preferences for males with sexual ornaments is still not well understood. Therefore, we investigated whether the use of public information in mate-choice copying can explain the development of mate preferences for a novel phenotype in male and female zebra finches (Taeniopygia guttata castanotis). In a binary choice situation, birds could choose between 2 conspecifics of the opposite sex of 2 different phenotypes: an unadorned phenotype and an adorned phenotype with a red feather on the forehead, simulating the novel phenotype. When no public information was provided, females and males spent a similar amount of time in front of individuals of both phenotypes. After observing a single, unadorned individual and a pair with 1 adorned partner for 2 h, females and males could choose between other individuals of both phenotypes in 2 consecutive mate-choice tests. Females spent significantly more time in front of males of the adorned phenotype after the observation period than before the observation period. This shows that females copied and generalized the mate choice of other females for males of the new phenotype. In contrast to females, males did not copy the mate choice of other males. Results from controls provided no alternative explanation for the change in mate choice in females. Our study shows that sexes differ in using public information in mate-choice decisions and that mate-choice copying is a meaningful mechanism for the cultural inheritance of mate preferences in female zebra finches.