Table 2.

Statistical summary table for tGSH and GSSG

	Estimate ± SE	dfden	F-value	P-value
tGSH (n = 743)
Habitat quality	0.12 ± 0.04	298.29	8.00	0.005
Sex (f)	0.071 ± 0.03	491.59	4.07	0.004
	Variance comp.  ± SE			Variance explained (%)
Nest box [Plot](r)	0.07 ± 0.04			7.31
Plot(r)	0			0
GSSG (n = 743)
Date	0.02 ± 0.01	647.69	11.23	0.001
	Variance comp. ± SE			Variance explained (%)
Nest box [Plot](r)	0.10 ± 0.04			10.49
Plot(r)	0			0

A summary table of the final GLMM for total (tGSH) and oxidized glutathione (GSSG) measured in great tit whole blood. Among the single parameters, breeding density, age, clutch size, date, date², and body condition had a P > 0.1, thus eliminated from the tGSH model. For GSSG, all except spring date were removed (see more statistical details in Material and Methods section).