Table 3.

Parameter estimates (± SE) and confidence intervals (CI; 95% and 85%) from the best supported linear mixed effect models explaining chick growth measurements (body mass (control/enlarged, n = 58/52 chicks), Tarsus (n = 56/50 chicks), bill (n = 56/50 chicks) and total head (n = 47/41 chicks) length) with candidate models including fixed effects of experimental group, chick age, habitat and laying date, and interactions between habitat and chick age, and between experimental group and chick age, and random effects of brood ID and chick ID.

Response				95% CI		85% CI
	Model	Estimate	SE	lower	upper	lower	upper	p
Mass	(Intercept)	1.130	0.030	1.070	1.191	1.086	1.175	< 0.001
	Group (enlarged)	− 0.084	0.039	− 0.163	− 0.006	− 0.141	− 0.027	0.038
	Habitat (marine)	− 0.221	0.033	− 0.287	− 0.154	− 0.270	− 0.172	< 0.001
	Age	− 0.013	0.002	− 0.018	− 0.008	− 0.017	− 0.010	< 0.001
	Habitat (marine) * Age	0.025	0.004	0.017	0.033	0.019	0.031	< 0.001
Tarsus	(Intercept)	1.028	0.008	1.012	1.045	1.016	1.041	< 0.001
	Group (enlarged)	− 0.036	0.011	− 0.058	− 0.015	− 0.052	− 0.021	0.002
	Habitat (marine)	− 0.030	0.009	− 0.049	− 0.011	− 0.044	− 0.016	0.002
	Age	− 0.003	6.9e–04	− 0.004	− 0.002	− 0.004	− 0.002	< 0.001
	Habitat (marine) * Age	0.005	0.001	0.003	0.008	0.004	0.007	< 0.001
Bill	(Intercept)	0.960	0.034	0.892	1.029	0.910	1.010	< 0.001
	Group (enlarged)	0.002	0.019	− 0.036	0.040	− 0.025	0.030	0.900
	Habitat (marine)	− 0.068	0.024	− 0.117	− 0.020	− 0.104	− 0.032	0.005
	Age	− 0.003	0.002	− 0.007	3.5e–04	− 0.006	− 0.001	0.075
	Laying date	0.005	0.002	3.6e–04	0.009	0.002	0.008	0.036
	Habitat (marine) * Age	0.007	0.003	3.8e–04	0.013	0.002	0.011	0.036
Head and bill	(Intercept)	1.003	0.006	0.100	1.016	0.994	1.013	< 0.001
	Group (enlarged)	− 0.009	0.009	− 0.028	0.010	− 0.023	0.004	0.328