Linear mixed model explaining absolute carotenoid chroma of yellow breast feathers in Great Tit nestlings.

For fixed effects, type 3 tests and denominator DF are presented, numerator DF = 1 in all cases. For random effects, covariance parameter estimates are presented (REML method). Likelihood ratio test of the overall significance of random effects: χ2 = 15.09, DF = 3, P = 0.002. P-values of significant factors are in bold. Least squares means ± SE for nestling reared by 1y old females: −0.58±0.01, nestling reared by older females: −0.55±0.01.*Estimate for 1y old (relative to older) females.**Estimate for reduced (relative to enlarged) broods.***PC1 of yolk antioxidants included the concentrations of vitamin A, vitamin E, lutein and zeaxanthin in egg yolk; all concentrations were log10-transformed.