Table 4. Results from the best-fit (lowest AICc) generalized linear mixed model (binomial distribution) testing the prediction that smaller bird species were more likely to win aggressive contests for resources when interacting with a more distantly-related species (n = 244 species pairs).

Fixed effects1	Estimate	SE	z	P
Intercept	−1.60	0.18	−9.08	<0.0001
Genetic distance2	0.89	0.35	2.59	0.0098

¹dependent = 0 if larger species was dominant, 1 if smaller species was dominant; taxonomic group included as a random effect.

²standardized prior to analysis by subtracting the mean and dividing by 2 standard deviations.