Table 1.

Results of ANOVA models examining stress-induced corticosterone (CORT) in superb starlings. (Stress-induced CORT was measured at 10, 30 and 60 min after capture during the pre-breeding periods from 2003 to 2005 (and at 90 min after capture in 2005) in birds of each breeding role (breeders, helpers or non-breeders/non-helpers). There was a significant effect of sampling time period in each year, but there was only a significant effect of breeding role in 2005 (the driest of the 3 years) when birds that became helpers had significantly higher stress-induced CORT than those that became breeders or non-breeders/non-helpers. There was a significant interaction in 2003 such that birds that became non-breeders/non-helpers had significantly higher stress-induced CORT than those that became breeders or helpers at 60 min after capture. Bold values indicate significance at p<0.05.)

year	rainfall (mm)	effect	d.f.	F	p
2003	91.2	time period	2, 153	24.02	0.0058
		breeding role	2, 153	0.30	0.76
		interaction	6, 153	3.34	0.012
2004	137.4	time period	2, 177	109.02	<0.0001
		breeding role	2, 177	3.69	0.12
		interaction	6, 177	0.33	0.86
2005	42.7	time period	3, 144	62.08	<0.0001
		breeding role	2, 144	20.99	0.002
		interaction	6, 144	0.25	0.96