Table 1.

Predictors of body mass in female and male tree swallows during breeding seasons from 2005 to 2011. These model-averaged estimates were obtained from LMMs with individual and farm identities as random effects and fixed effects centred on their mean. Predictors in italic are statistically significant (i.e. their 95% confidence interval (CI) does not include zero).

fixed effects	females (n = 2070; 1017 individuals)				males (n = 848; 556 individuals)
	estimate	s.e.	lower CI	upper CI	estimate	s.e.	lower CI	upper CI
intercept	22.6	0.1	22.3	22.8	20.7	0.08	20.5	20.9
year	−0.264	0.025	−0.312	−0.215	−0.056	0.018	−0.091	−0.021
Julian date	−0.009	0.006	−0.021	0.003	−0.038	0.005	−0.048	−0.028
no. days since laying date	−0.082	0.008	−0.097	−0.067	−0.022	0.007	−0.035	−0.008
time of day	1.366	0.320	0.740	1.990	0.758	0.246	0.277	1.240
proportion of intensive cultures within 5 km radius (intensive)	0.005	0.006	−0.006	0.016	0.007	0.005	−0.002	0.016
wing length (mm)	0.061	0.014	0.034	0.089	0.023	0.006	0.010	0.036
age (SY)	−0.296	0.130	−0.550	−0.042	—	—	—	—
clutch size	0.200	0.049	0.104	0.296	−0.021	0.039	−0.091	0.055
days since laying × intensive	−0.0002	−0.0002	−0.0006	0.0002	−0.0002	0.0002	−0.0006	0.0003
days since laying × clutch size	−0.0050	0.0040	−0.0129	0.0029	0.0081	0.0056	−0.0029	0.0191
year × intensive	−0.0005	0.0009	−0.0023	0.0013	−0.0012	0.0007	−0.0026	0.0002