Contrasting patterns of selection on the size and coloration of a female plumage ornament in common yellowthroats

Abstract

Females often possess ornaments that appear smaller and duller than homologous traits in males. These ornaments may arise as nonfunctional by-products of sexual selection in males and cause negative viability or fecundity selection in females in proportion to the cost of their production and maintenance. Alternatively, female ornaments may function as signals of quality that are maintained by sexual or social selection. In a 4-year study of 83 female common yellowthroats (Geothlypis trichas) and their 222 young, we found strong viability and fecundity selection on the yellow bib, a carotenoid-based plumage ornament that is a target of sexual selection in males. Females with larger bibs were older, larger and more fecund than females with smaller bibs. However, bib size positively covaried with bib total brightness and carotenoid chroma, aspects of bib coloration that were under negative viability and fecundity selection. Females with more colourful bibs laid fewer eggs in their first clutch, were more likely to suffer total brood loss due to predation and were less likely to return to the study area. Selection against bib coloration limits the value of bib size as a quality indicator in females and may constrain the elaboration of bib attributes in males.

Genetic basis and fitness correlates of dynamic carotenoid‐based ornamental coloration in male and female common kestrels Falco tinnunculus

“…On the other hand, the other two components of skin coloration, hue and brightness, showed very low levels of additive variance, suggesting that their expression is mostly environmentally mediated. As it has previously been shown in other bird species that chroma can be considered a proxy of carotenoid content in yellow traits (Peters et al ., ; Freeman‐Gallant et al ., ; Tonra et al ., ), our results reinforce the idea that despite their environmental dependency (Martinez‐Padilla et al ., ), dynamic, carotenoid‐based signals may have a significant genetic component (Velando et al ., ; Evans & Sheldon, ). This is likely to be mediated by additive genetic variation in those aspects of behaviour (e.g.…”

A novel method of comparing mating success and survival reveals similar sexual and viability selection for mobility traits in female tree crickets

“…There was a possibility in female O. nigricornis that sexually selected traits may have carried viability costs because the risk of predation associated with those traits may have been offset by the fitness benefits of receiving more nuptial gifts, but this does not appear to be the case. Such an opposing relationship between sexual success and survival has been observed in females of other species like common yellowthroats ( Geothlypis trichas ), where females with brighter, yellower bibs are more likely to mate with high‐quality males, but will lay smaller clutches and are more likely to lose their broods to nest predators (Freeman‐Gallant et al ., ).…”

Lack of conspecific visual discrimination between second-year males and females in the Saffron Finch

“…Several studies have found that female coloration is important in male mate choice [75,76], reproductive success ([77–79], but see [80]), and parental care [79]. Females of several dichromatic species display ornamentation that is similar to males, but often reduced in intensity or extent [32,34].…”