Table 2.

Effects of ambient temperature (averaged from midnight–midnight), study area, female body mass, the number of eggs laid after the date DEE was measured (eggs left), various egg characteristics, final clutch size and date on daily energy expenditure (DEE) during egg laying analysed using the full dataset (A); to test the difference between earlier and later laying females we used data from the Hoge Veluwe females for which DEE (kJ day⁻¹) was measured on egg 4 or 8 (egg number; late vs. early breeders); first, we ran a 2-way ANOVA (B) followed by linear mixed model correcting for temperature and female body mass (C)

	Variable	Estimate	SE	df	F	P
A	Linear mixed model: full data set (n = 78 females, 78 measurements)
	Temperature			1	42.9	<0.0001
	Area
	Hoge Veluwe	31.02	12.46	1	5.01	0.029
	Oosterhout	33.52	12.59
	Female body mass	2.93	0.64	1	20.92	<0.0001
	Temperature × area
	Hoge Veluwe	−1.14	0.34	1	0.047	0.83
	Oosterhout	−1.03	0.53
	Year (2009)	2.96	1.93	1	3.60	0.06
	Eggs left	0.32	0.30	1	1.13	0.29
	Mass yolk	−6.20	17.06	1	0.13	0.72
	Mass albumen	3.32	6.19	1	0.29	0.59
	Final clutch size	0.21	0.33	1	0.41	0.53
	Date	−0.06	0.15	1	0.14	0.72
B	2-way ANOVA: early versus late breeders (n = 43, only Hoge Veluwe area)
	Female body mass	2.16	0.98	1	4.87	0.03
	Date			8	1.37	0.25
	Egg number	−2.22	1.76	1	1.58	0.22
	Date × egg number			8	0.58	0.78
C	Linear mixed model: early versus late breeders (n = 43, only Hoge Veluwe area)
	Temperature	−1.19	0.39	1	8.99	0.005
	Female body mass	2.18	0.89	1	5.98	0.020
	Egg number	−1.37	1.65	1	0.69	0.41
	Egg number × temperature	−0.31	0.84	1	0.14	0.72

Significant values, p < 0.05, in bold