Dependence of protein carbonyl (PCs) and glutathione peroxidase (GPx) concentration in European robins on time since dawn (third-order polynomial), muscle score and age in a General linear model.

N = 95 for both models. Fat score was not significant (ns) and removed from both models; time since dawn cubic and squared and age were not significant in the model for PCs and removed. The effect for the variable muscle score is given for muscle scores 1 and 2 versus muscle score 3, and for first-year birds versus adults.