Data from: Tail color signals performance in blue tit nestlings

Indirect sexual selection arises when reproductive individuals choose
their mates based on heritable ornaments that are genetically correlated
to fitness. Evidence for genetic associations between ornamental
coloration and fitness remain scarce. In this study we investigate the
quantitative genetic relationship between different aspects of tail
structural coloration (brightness, hue and UV chroma) and performance
(cell mediated immunity, body mass and wing length) in blue tit (Cyanistes
caeruleus) nestlings. In line with previous studies, we find low
heritability for structural coloration and moderate heritability for
performance measures. Multivariate animal models show positive genetic
correlations between the three measures of performance, indicating
quantitative genetic variation for overall performance while tail
brightness and UV chroma, two genetically independent color measures, are
genetically correlated with performance (positively and negatively
respectively). Our results suggest that mate choice based on independent
aspects of tail coloration can have fitness payoffs in blue tits and
provide support for the indirect benefits hypothesis. However, low
heritability of tail structural coloration implies that indirect sexual
selection on mate choice for this ornament will be a weak evolutionary
force.