Comparison of model fit for different generalized linear models, with taxonomic group entered as a predictor that include all possible combinations of predictor variables.

Models tested the prediction that the advantage of large size in aggressive contests for resources declines with genetic distance among interacting bird species (n = 244 species pairs).1 numbers for predictor variables are effect sizes.2 plus sign (+) indicates that the predictor variable (factor) was included in the model.3 long dash (—) indicates that the predictor variable was absent from the model.Comparison of model fit for different generalized linear models, with taxonomic group entered as a predictor that include all possible combinations of predictor variables.