Table 3:

Linear models testing effects of treatment, hormone levels, and other covariates on chick growth . Estimates use saline as the reference for treatment and Y1 as the reference for year. Inclusion and exclusion of covariates was determined via systematic comparison of candidate models (supplemental tables 10–13). Signficant predictors are bolded (p<0.05). Letters denote separate models. Analyses a-c focus on effects occuring within one day of male treatment at the time of peak growth; analysis d measured delayed effects at d12 post-hatch

Response variable	Predictor variable	Estimate (± 95% CI)	F-statistic	p-value
Avg chick growth (Δg)
(a)	Treatment	0.37 ± 0.16	F1,53=5.41	p=0.024
	Date	−0.020 ± 0.007	F1,53=7.38	p=0.009
	Elapsed time	0.27 ± 0.052	F1,53 =23.24	p<0.0001
(b)	Avg M visits/hr	0.085 ± 0.034	F1,30 =9.49	p=0.0046
	Elapsed time	0.22 ± 0.067	F1,30 =11.01	p=0.0025
(c)	GnRH ΔT	0.59 ± 0.15	F1,28 =14.87	p=0.0007
	Elapsed time	0.30 ± 0.05	F1,28 =30.52	p<0.0001
Avg d12 mass (g)
(d)	Treatment	−0.16 ± 0.64	F1,50=1.24	p=0.27
	Brood size	−1.00 ± 0.39	F1,50=9.36	p=0.0037
	Male mass	1.19 ± 0.31	F1,50=11.38	p=0.0015
	Year	1.93 ± 0.71 (Y2)	F2,50=5.21	p=0.0092
		2.28 ± 0.82 (Y3)