Table 1.

Relationship between neutral heterozygosity and nestling fitness traits. (A) Nestling swelling response, (B) feather length, and (C) body condition

Variables	Standardized estimate	Estimate	SE	F	df	P
(A)
Intercept		−38.698	20.838	3.449	1, 583	0.064
HetHLneutral	0.093	20.112	9.765	4.242	1, 583	0.040
HetHLneutral foster male	0.034	7.174	15.047	0.227	1, 84	0.635
HetHLneutral foster female	0.097	20.994	16.173	1.685	1, 84	0.198
Sexa	−0.048	−1.427	0.881	2.627	1, 583	0.106
Flea infestationb	0.535	15.793	10.100	2.445	1, 84	0.122
Enlarged broodc	0.092	2.789	2.617	0.956	2, 84	0.389
Reduced broodc	−0.029	−0.943	2.722	–	–	–
Hatching rankd	0.04	1.268	0.950	1.782	1, 583	0.183
Original brood size	0.011	0.097	0.715	0.018	1, 84	0.893
Weight	0.237	1.871	0.431	18.846	1, 583	<0.001
HetHLneutral * Flea infestationb	−0.759	−30.170	13.463	5.022	1, 583	0.025
(B)
Intercept		45.459	5.172	77.240	1, 628	<0.001
HetHLneutral	−0.026	−1.366	1.903	0.515	1, 628	0.473
HetHLneutral foster male	−0.086	−4.403	4.438	0.984	1, 90	0.324
HetHLneutral foster female	−0.061	−3.220	4.743	0.461	1, 90	0.499
Sexa	0.032	0.231	0.156	2.207	1, 628	0.138
Flea infestationb	−0.691	−4.964	1.997	6.181	1, 90	0.015
Enlarged broodc	−0.202	−1.495	0.765	3.325	2, 90	0.040
Reduced broodc	0.062	0.480	0.786	–	–	–
Hatching rankd	−0.387	−2.992	0.176	287.853	1, 628	<0.001
Original brood size	−0.128	−0.272	0.193	1.988	1, 90	0.162
HetHLneutral * Flea infestationb	0.605	5.876	2.593	5.135	1, 628	0.024
(C)
Intercept		1.070	0.754	2.011	1, 607	0.157
HetHLneutral	−0.084	−0.929	0.847	1.204	1, 607	0.273
HetHLneutral foster male	0.013	0.139	0.423	0.108	1, 88	0.743
HetHLneutral foster female	−0.027	−0.299	0.437	0.469	1, 88	0.495
Sexa	−0.818	−1.263	0.868	2.117	1, 607	0.146
Flea infestationb	−1.176	−1.819	0.870	4.365	1, 88	0.040
Enlarged broodc	−0.032	−0.051	0.070	0.365	2, 88	0.695
Reduced broodc	0.003	0.005	0.078	–	–	–
Hatching rankd	−0.226	−0.377	0.062	37.504	1, 607	<0.001
Original brood size	−0.057	−0.026	0.019	1.836	1, 88	0.179
HetHLneutral * Sexa	0.963	2.013	1.186	2.880	1, 607	0.090
HetHLneutral * Flea infestationb	1.241	2.593	1.187	4.772	1, 607	0.029
Sex * Flea infestationa,b	1.545	2.663	1.203	4.900	1, 607	0.027
HetHLneutral * Sex * Flea infestationa,b	−1.669	−3.908	1.639	5.688	1, 607	0.017

SE, standard error.

Results from linear mixed-effect models. All models included nest identity as a random factor to control for the nonindependence among siblings. In the model for the swelling response, the random structure was fitted as nest identity nested within observer. Significant main effects and interactions are shown in bold.

^aRelative to female nestlings.

^bRelative to noninfested broods.

^cRelative to unchanged brood size.

^dRelative to first-hatched chicks.