Table 2.

Rate of double brooding and the mean clutch initiation date across female ages in prothonotary warblers. Mean clutch initiation dates are rounded to the nearest day. Females greater than 6 years were combined due to small sample sizes for these older birds

Years Breeding	N	Number to double brood	Percentage to double brood	Mean clutch initiation date (±SD)
1	317	27	7.9	May 6 (5.4)
2	560	75	11.8	May 4 (5.5)
3	452	101	18.3	May 3/4 (5.4)
4	199	58	22.6	May 2 (5.3)
5	105	32	23.4	May 3 (5.3)
6+	74	27	26.7	May 3 (5.5)