Eggshell coloration in relation to male ornamentation, female condition and egg quality in the collared flycatcherFicedula albicollis

Abstract

The blue-green eggshell pigment biliverdin is an efficient antioxidant, the deposition of which may be costly and act as a handicap to the female's antioxidant capacity. Thus, it is hypothesized that there exists a positive correlation between the degree of eggshell coloration and the condition and health state of the mother. In this study, we measured the blue-green chroma of collared flycatcher Ficedula albicollis eggs, and investigated the associations between egg colour and parental characteristics, laying date, clutch size and laying order. We also analysed the possible correlations between egg size, yolk carotenoid and antibody levels and eggshell pigmentation. Our results revealed no significant relationships between egg colour and female age, morphological and serological variables. Blue-green colour intensity of eggs increased throughout the breeding season, which could be the result of either a proximate constraint or an adaptive strategy. We found a positive association between egg colour saturation and yolk lutein concentration. This relationship could be the result of the seasonal improvement of caterpillar supply, which could influence the deposition of both components into the egg. Furthermore, we found that females mated to lower-quality males produced eggs with higher biliverdin pigmentation. It is possible that deposition of biliverdin is correlated to some unmeasured aspect of egg quality that could enhance the viability of offspring of lower-quality fathers. We found that intensity of blue-green coloration increased with laying order between the first and fifth eggs.

Pigment limitation and female reproductive characteristics influence egg shell spottiness and ground colour variation in the house sparrow (Passer domesticus)

“…Previous findings on free-living bird populations of pied flycatchers (Ficedula hypoleuca) and collared flycatchers (Ficedula albicollis) also pointed to a short-term limitation or cost in the deposition of the biliverdin pigment, since egg darkness decreased along the laying sequence Krist and Grim 2007). However, other studies found the opposite relationship, where the last-laid eggs were the most bluish ones (Siefferman et al 2006;Hargitai et al 2008). This suggests different reproductive strategies across species.…”

“…Female age significantly affected the proportion of bluish eggs and spot patterns: the proportion of bluish eggs and spot darkness declined in females older than 4 years. Some studies failed to find effects of age on egg ground colour (Hargitai et al 2008) or spot patterns (Sanz and García-Navas 2009). Other studies found that, compared to first-time breeders, adults laid more pigmented (Siefferman et al 2006), brighter (Martínez-de la Puente et al 2007) or less darkly spotted eggs (Gosler et al 2005).…”

“…A growing number of studies have corroborated that the deposition of the antioxidant pigment biliverdin in the eggshell may depend on a high laying female antioxidant capacity (Hanley et al 2008), and may be indicative of female quality in terms of immune system Jagannath et al 2008) or physical condition (Moreno et al 2006;Siefferman et al 2006;Krist and Grim 2007;Soler et al 2008). However, some studies in other bird species did not find such clear support for the signalling function of the biliverdin pigment (Hargitai et al 2008;López-Rull et al 2008;Hanley et al 2008;Hanley and Doucet 2009), stressing the need for more studies on this subject.…”

The impact of eggshell colour and spot area in Japanese quails: II. Slaughter and carcass characteristic

“…On the basis of these data, the researchers suggested that the brightness of the eggshell would decrease whilst the colour intensity of the eggshell would increase in eggs laid by female quails fed as such. Several studies have pointed out to a positive correlation between eggshell colour and the health status of the female and/or chick, and parameters of immune capacity such as maternal antibody levels and yolk testosterone and yolk lutein concentrations (Moreno et al, 2005;Hargitai et al, 2008). The pigments held responsible for the formation of reddish spots in spotted eggs, according to the structuralfunction hypothesis, namely, the protoporphyrins, are R. Bras.…”

Condition-dependent strategies of eggshell pigmentation: an experimental study of Japanese quail (Coturnix coturnix japonica)

“…maternal antibodies, yolk testosterone, yolk lutein) (Moreno et al, 2005;Hargitai et al, 2008). However, findings from an increasing number of studies are now in conflict with the predictions of this hypothesis.…”