Table 1.

General linear mixed model to test the effect of paternity on weight and tarsus length in nestlings from 83 broods with mixed paternity. (Extra-pair young (n=163) were heavier and they had longer tarsi compared with within-pair young (n=165). The different factors in the model are: paternity; sex; and age. Brood identity had a significant effect and was included as a random factor in the model. Interactions between factors were not significant.)

parameter	effect	estimate	F	p
weight (g)	paternity	0.226	7.1	0.010
	sex	0.392	20.2	0.001
	age	1.100	23.3	0.001
tarsus length (mm)	paternity	0.121	5.7	0.020
	sex	0.076	2.2	0.150
	age	0.901	34.3	0.001