Deciding Who to Mate With: Do Female Finches Follow Fashion?

Choosing an appropriate mate is one of the most important decisions that any animal has to make. The traditional view in non-human systems is that animals are largely slaves to their genes and an individual’s mate choice is handed down from their parents. However, in recent years it has become clear that many animals show active decision making in who to mate with and that females may copy mate preferences from other females in the population. In other words, females’ mating decisions are affected by the current fashion in their population. Here, we explore whether “mate choice copying” occurs in a model monogamous mating system—the zebra finch. Females were given the opportunity to observe another female courting a particular type of male (we manipulated male appearance by placing small colored leg bands on each bird). In preference tests, our focal females significantly shifted their mate preferences towards the type of male that they had observed as being courted by other females. Therefore, female finches do seem to copy mate preferences, implying that there is social inheritance of information that fundamentally affects mating decisions. This is one of the first demonstrations of mate choice copying in any monogamous system and implies that many other birds may also use social