TABLE 1.

Results of analysis of covariance (ANCOVA) of T_bmean, T_bmin, T_bmax, and T_bmedian (°C) in response to food deprivation conditions separately for day and night.

Variable	Young		Middle-aged		Old		Age factor			Body mass
	LSM	SE	LSM	SE	LSM	SE	F	df	p	F	df	p
Day
Tb mean	41.8	0.1	41.4	0.2	41.5	0.2	1.01	2,20	0.38	1.28	2,20	0.27
Tb min	40.8	0.1	40.5	0.2	40.4	0.2	1.41	2,20	0.27	0.03	2,20	0.87
Tb max	42.6	0.0	42.3	0.1	42.5	0.1	1.44	2,20	0.26	6.38	2,20	0.02
Tb median	41.8	0.1	41.4	0.2	41.5	0.2	0.94	2,20	0.41	1.18	2,20	0.29
Night
Tb mean	38.0	0.1	37.5	0.1	37.2	0.2	4.46	2,20	0.02	0.31	2,20	0.58
Tb min	37.2	0.1	36.7	0.2	36.6	0.2	3.40	2,20	0.05	0.24	2,20	0.63
Tb max	40.6	0.2	40.1	0.2	39.9	0.3	2.50	2,20	0.11	2.32	2,20	0.14
Tb median	37.7	0.1	37.3	0.2	37.0	0.2	4.37	2,20	0.02	0.24	2,20	0.63

Age group, 12 young (1.1–1.3 years old), 8 middle-aged (2.4–2.8 years old), and 5 old (4.2–7.5 years) birds, was included as a categorical variable. Body mass (g) was recorded just after lights on and was included as a covariate in the model. Least squares means (LSM), standard error (SE), statistics; F-value, degrees of freedom for numerator and denominator (df) and p-value based on Satterthwaite’s method approximation. Bold letters indicate statistical significance of the effect smaller or equals to 0.05.