Table 1.

Effects of brood manipulation on interclutch interval, second brood characteristics (unmanipulated), overall seasonal fecundity and between-year differences in standardized female plumage. Means are given with se and samples sizes in parentheses.

Response to treatment	Reduced*	Enlarged†	Statistic	P
Interclutch interval (days)	28.3 ± 1.2 (23)	37.1 ± 3.2 (15)	t = 3.0	0.005
Clutch size of 2nd nest	4.26 ± 0.13 (23)	4.27 ± 0.18 (15)	U = 170	0.75
Brood size of 2nd nest	2.74 ± 0.36 (23)	2.73 ± 0.47 (15)	U = 169	0.98
No. of nestlings fledged from 2nd nest	2.01 ± 0.38 (23)	1.60 ± 0.50 (15)	U = 143	0.38
Total nestlings reared	5.86 ± 0.42 (44)	7.56 ± 0.35 (39)	t = 3.1	0.003
Change in female plumage brightness	− 0.32 ± 0.37 (13)	− 0.12 ± 0.36 (8)	t = 0.4	0.73
Change in female plumage UV chroma	0.11 ± 0.31 (13)	− 0.12 ± 0.31 (8)	t = 0.5	0.63
Change in female plumage hue	− 0.17 ± 0.31 (13)	0.16 ± 0.50 (8)	t = 0.6	0.57

^*Two chicks removed.

^†Two chicks added.