LAUSR

The study of mate choice and sex roles has come a long way from the assumption that only males are promiscuous and females are coy. However, fragments of this mindset might still influence our research today. In their review, Richardson and Zuk (2022) bring forward the important issue that many mate choice experiments use only virgin females for measuring female preferences, despite the fact that in systems with multiply mating females, most of the mating events should occur with non-virgin females. As full monandry has been found to be much rarer than polyandry in most animal species (Taylor et al. 2014), this is an issue that most mate choice studies should consider carefully. We find Richardson and Zuk’s review both informative and eye-opening. This is so, despite the fact that their meta-analysis did not reveal large biases in mating preferences between virgin and non-virgin females in previously published literature. Their review still shows how using virgin females is the standard of most mate choice studies, and that only a few papers explicitly state that mated females were used. We strongly agree that more studies should be aware of the potential shortcomings that arise from this discrep-ancy between experimental animals and wild animal populations. This problem has gone largely unnoticed until now, as even in the otherwise comprehensive book on mate choice by Rosenthal (2017), virgin females are only mentioned when discussing potential male preferences. While the meta-analysis by Richardson and Zuk did not find differences in choosiness between virgin and mated females, this might be due partly to the low number of publications with non-virgin females and thus warrants further investigating. More studies comparing experimentally these differences within single systems would be especially helpful to evaluate if this is a large concern for mate choice research. There are several reasons why using virgin females might be justified in mate choice studies. Virgin females are often seen as a “clean slate” unbiased by previous mating experience. A study on reproductive isolation might therefore