A Female Color Ornament Honestly Signals Fecundity

Abstract

In many species, particularly in ectothermic vertebrates, not only males but also females show bright body colorations. In Alpine newts, Ichthyosaura alpestris, both sexes have colorful orange bellies. This coloration varies in redness (yellowish to dark orange) among individuals, and previous work has shown that courting males preferred females with more orange bellies. Because males in this species are likely to be limited in their mating capacity, selection would favor this preference if this coloration honestly signals female quality. In this study, we investigated whether female belly coloration can predict individual fecundity in which case males might have the chance to fertilize more eggs when they choose to mate with a more ornamented female. We found that more orange females were more fertile than less orange ones. Additionally, we saw that more ornamented females could lay their eggs faster, which means that they ceased egg laying at a similar time as less ornamented females despite the greater number of eggs. This suggests that female color can convey quality advantages in a species with no sex-role reversal much in the same way as male colors can, making female ornaments subject to sexual selection acting directly on them.

Phenotypic and environmental predictors of reproductive success in painted turtles

“…Males with bright colors or specific hues experience increased fitness through female choice (e.g., Safran et al 2005). Female color also may be important for male mate choice and reproductive success (Lüdtke and Foerster 2019). Indeed, color and health are associated in pond turtles of both sexes.…”

Does egg carotenoid improve larval quality in Arctic charr (Salvelinus alpinus)?

“…This ambiguity has been suggested to be due to between‐species variation in ornament‐fecundity relationships deciding whether or not male mate choice is adaptive (Watson & Simmons, 2010). Studies published in the later years give ambiguous conclusions as well, with some studies being in accordance with (Cantarero et al, 2017; Cotton et al, 2015; Hernández et al, 2021; Lüdtke & Foerster, 2018, 2019), and others contrary to (Caro et al, 2021, and Rigaill & Garcia, 2021) predictions from the direct selection hypothesis. Some studies give support to the genetic correlation hypothesis (Sganga & Greco, 2019), and the social selection hypothesis (Enbody et al, 2018, see also Kroken et al, 2021).…”

Carotenoids‐based reddish pelvic spines in nonreproducing female and male sticklebacks (Gasterosteus aculeatus) – Signalling social dominance?

“…Empirical support for the different hypotheses on evolution of ornaments in females of mutually ornamented species in general are ambiguous (reviewed by Amundsen, 2000 , Kraaijeveld et al., 2007 , Clutton‐Brock, 2009 , Nordeide et al., 2013 , Svensson & Wong, 2011 , Tobias et al., 2012 , see also Lüdtke & Foerster, 2019 , Lüdtke & Foerster, 2018 , Cotton et al., 2014 , Sganga & Greco, 2019 , Enbody et al., 2018 , LaPlante, 2015 , Belliure et al., 2018 ). The shape of the association between ornaments and fecundity may vary among species and at least part of this variation may affect whether male mate choice of the more showy females is adaptive or not (Watson & Simmons, 2010 ).…”