Table 2 Significant predictors of male quality in satin bowerbirds.

Dependent variables Significant predictors ß' F p df

I. Ectoparasites Bower quality score (R2 =.51) -0.72 8.4 .02 1,8
II. Endoparasites Rump UVV-brightness (R2 =.50) -0.70 8.9 .02 1,8
III. Feather growth rate Whole model (R2 =.74) 6.7 .02 3,9
    PC1 plumage color score -1.39 17.8 .004 1,9
    Wing coverts UVV-brightness 0.66 5.9 .04 1,9
    Rump UVV-brightness 0.63 5.0 .05 1,9
IV. Body size Whole model (R2 =.82) 8.9 .01 3,8
    Rump UVV-brightness 0.83 16.7 .006 1,8
    Bower quality score -0.89 10.4 .02 1,8
    Number of decorations 0.77 8.9 .02 1,8

Each model was constructed using backward stepwise multiple regression analysis with both bower features (bower quality score, number of decorations) and plumage features (PC1 plumage color score, UVV-brightness of the wing coverts, mantle, rump, and breast) as independent variables. Standardized regression coefficients (ß') and significance tests are shown for each significant predictor variable.