More colourful eggs induce a higher relative paternal investment in the pied flycatcher Ficedula hypoleuca: a cross‐fostering experiment

Abstract

More colourful eggs induce a higher relative paternal investment in the pied flycatcher Ficedula hypoleuca : a cross-fostering experiment. Á J. Avian Biol. 37: 555 Á560.The signalling hypothesis of eggshell colouration in birds posits that females of species with blue-green eggs signal their phenotypic quality or the quality of their eggs to their mates through deposition of the antioxidant biliverdin as pigment. Males respond by investing more in the offspring. Through a cross-fostering experiment where we have exchanged whole clutches between pairs of pied flycatcher Ficedula hypoleuca nests, we managed to break potential associations between female quality and clutch chromaticity. We show that males respond to incubated clutches with more variable and higher peak values in blue-green chroma through a higher proportional investment in nestling provisioning on day 4 of the nestling period, when males invest more heavily than females in provisioning. More variable clutches show higher peak chroma values. We also show that egg colour during the two-week incubation period has a significant effect, which is not found for the colour of eggs during the laying period. Finally, the proportion of male provisioning visits affects negatively female brooding effort and nestling mortality, and thereby has positive effects on female fitness. Blue-green chroma in the pied flycatcher functions as a signal of female or clutch quality to males which respond by adjusting their relative investment with respect to total pair effort.

Pre-laying nutrition mediates maternal effects on offspring immune capacity and growth in the pied flycatcher

“…These exchanges have not been included here. Thus, the samples of nests diVer between this study (26 exchanges) and Moreno et al (2006b), who did not Wnd an eVect of egg colour on nestling traits.…”

“…Accordingly, the detection of maternal eVects may be rendered more diYcult as the egg remaining in the original nest may obscure potential treatment eVects. All 35 exchanges were included in a study on egg colouration and paternal care (Moreno et al 2006b). In that study we did not deal with potential eVects of food supplementation at laying on male provisioning eVort (although including food supplementation does not change the results presented there), so nine exchanges were made between nests of the same treatment.…”

“…Nests were also Wlmed on day 4 for the study of egg colouration and paternal care (Moreno et al 2006b), but these recordings were too temporally removed from nestling immune capacity measures to be of use in the present study. Video cameras were placed several metres away from the nest box and registered parental visits during periods of 1-2 h (mean 74.2 § SE 3.4 min, n = 42).…”

“…Rearing environment and genetic background are thus subsumed in nest of rearing in our design, while prelaying maternal eVects are expressed in the experimental treatment. The study has controlled for the three most important environmental eVects operating during the nestling period in our study populations, namely mite infestation (Lobato et al 2005;Merino and Potti 1995;Merino et al 1998;Moreno et al 1999Moreno et al , 2002aMoreno et al , 2004Potti et al 1999), parental provisioning Moreno et al 1997Moreno et al , 2004Moreno et al , 2006b) and breeding phenology (Morales et al 2007). The levels of immunoglobulins and mass and skeletal size of chicks before Xedging were ascertained.…”

The intensity threshold of colour vision in a passerine bird, the blue tit

“…For example, there is a debate concerning the intensity limit of the loss of colour vision in birds (Holveck et al, 2010;Avilés et al, 2011). Many experiments in cavity-nesting birds (mostly passerines) show that parents adjust their behaviour to colour-manipulated eggs (Moreno et al, 2006;Martínez-de la Puente et al, 2007;Sanz and García-Navas, 2009;Antonov et al, 2011;Avilés et al, 2011) or chicks (Jourdie et al, 2004;Bize et al, 2006;Tanner and Richner, 2008;Dugas, 2009;Wiebe and Slagsvold, 2009). Whether they use colour and/or achromatic cues remains unknown (but see Antonov et al, 2011).…”