More ornamented females produce higher-quality offspring in a socially monogamous bird: an experimental study in the great tit (Parus major)

Abstract

IntroductionAnimals are often conspicuously colored and explanations range from aposematism and mimicry to sexual selection. Although sexual selection explains vivid coloration in males, functional significance of vivid coloration in females of socially monogamous species remains unclear. The hypothesis of mutual mate choice predicts that more ornamented females produce offspring of higher quality. We tested this prediction in the great tit (Parus major), a small, insectivorous, socially monogamous passerine.ResultsIn both females and males we quantified three ornaments that have been hypothesized to have signaling role in this species (size of black breast stripe, carotenoid chroma of yellow breast feathers, immaculateness of the white cheek). We swapped broods between nests soon after hatching, thus separating genetic plus pre-hatching vs. post-hatching effects on offspring performance. Body mass of offspring at 14 days of age was positively related to the area of black breast stripe of genetic mothers. Immune response to a novel antigen (phytohaemagglutinin) at 14 days of age was positively related to the immaculateness of the white cheek patch of both genetic and foster mothers.ConclusionsWe showed that females with more elaborate ornaments produced higher-quality offspring and we discuss potential proximate mechanisms of these relationships. We conclude that as more elaborate ornaments were reliable signals of offspring quality, direct selection by male mate choice might have been responsible for the evolution and/or maintenance of these signaling traits in females.

Hot or Not: The Effects of Exogenous Testosterone on Female Attractiveness to Male Conspecifics in the Budgerigar

“…Furthermore, several studies indicate that female ornamental traits correlate with a variety of indicators of female quality and reproductive potential (e.g. female survival, competitive ability, offspring provisioning, clutch size, offspring quality and fledgling success [86–90];; see 91 for a review). These findings support the assumption that ornamental traits may have the potential to function as signals of individual quality, not only in males but also in females.…”

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

“…By contrast, female ornamentation is often positively correlated with indices of individual quality, pointing to a potential role for female ornaments in sexual or social signalling (reviewed in Amundsen & Pärn, ; Nordeide et al ., ; Tobias et al ., ). Female plumage ornaments vary with age and condition (Johnsen et al ., ; Dreiss & Roulin, ); parasite load, immune function and physiological stress (Roulin et al ., , ; Hill, ; Kelly et al ., ); parental effort (Siefferman & Hill, ); annual fecundity (Jawor et al ., ); offspring quality (Remeš & Matysioková, ); and lifetime reproductive success (Roulin et al ., ; Potti et al ., ). Further, experimental manipulation of female nutritional state and reproductive effort has been shown to affect both carotenoid‐based and structurally based plumage ornaments (Siefferman & Hill, ; Doutrelant et al ., , ).…”

Vitamin E improves growth of collared flycatcherFicedula albicollisyoung: a supplementation experiment

“…Caterpillars are estimated to contain more α‐tocopherol than aerial insects fed by barn swallow parents to their nestlings (de Ayala et al , Arnold et al ). Caterpillars dominate both great and blue tit nestling diet (Cholewa and Wesołowski , Remeš and Matysioková ), but their share of collared flycatcher nestling diet is lower (Cholewa and Wesołowski ; see also Material and methods). Second, while tocopherol content of caterpillars increases over season, availability of tocopherol‐rich caterpillars sharply declines towards the end of season (Arnold et al ).…”