We suggest this may be because of the method of mate assessment in L. equestris, which appears to be primarily via contact cues, which may limit simultaneous comparison between options.
Mate-choice copying can be beneficial if it reduces mate assessment costs and improves outcomes, especially for inexperienced individuals that copy the choices of more experienced conspecifics [5].
Partners' availability, sampling strategies, competition within one sex, coercion, environmental influence on mate assessment, or preferences exerted by the other sex (when mate choice is mutual), are examples of other factors apart from preferences that can have a major influence on the outcome of pair formation.
Second, G. gracilicornis females may delay intromission in order to carefully assess the male's "quality," and therefore may display more resistance to some males (physically and by delaying genitalia protrusion), and less resistant to others of better quality (Mate assessment hypothesis).
We suggest that the fact that patterns of variability are broadly similar in males and females might indicate that ornaments may be more often than expected used for mutual mate assessment [53] or be important for status signalling in both sexes, as has been suggested for highly variable morphometric ornaments in females [10].
This approach enabled us to determine whether changes in female interspecific mate assessment based on individual visual signals correspond to changes in male signals resulting from EDC exposure.
This might be related to the short adult lifespan, with olfaction being a more time-efficient modality for host and mate assessment, occurring during flight at a distance rather than after landing via contact chemoreception.
Consistent with this direct physiological role of carotenoids, we observed that carotenoid supplementation increased both female responsiveness to males and their general activity in the mate choice context, thus supplemented females may have been better able to meet the costs of active mate assessment and selection.
One can assume a similar interaction between UV and red color components of male sticklebacks that may be important for female mate assessment since females in our experiment were more attracted to males presented under the SW- and, even though to a lesser extent, MW- treatment filters, both enabling the transmission of UV and long-wave light.
Personal identifiers were not available in our MATE assessments, preventing the use of a matched-pairs t test; we therefore used a less powerful independent-samples t test when analyzing the MATE results.
