Mean (SE) tetrahedral color component values of males or females that did or did not survive.

Surviving and non-surviving individuals were matched for year and age and, whenever possible (91% of the cases), for breeding site and capture date. Increasing values of θ indicate paler, relatively more eumelanic plumage. Significance of the deviation of mean differences between surviving and non-surviving individuals from zero was assessed by t-tests. Sample sizes are 108 pairs of males and 66 pairs of females.