Yellow-rumped Warbler - Setophaga coronata

Yellow-rumped Warbler has a partial preformative molt and partial prealternate molts that typically includes some of the greater coverts. Sex can generally be differentiated by plumage, although less reliably so for FCF (HY/SY) individuals, some of which are best left as sex unknown.

The two subspecies of Yellow-rumped Warbler (Audubon's Warbler, S.c. auduboni; Myrtle Warbler, S.c. coronata) are generally separable by plumage; guidelines for age and sex determination are believed to be largely applicable to both.

Quick tips

• Examine the primary coverts - on FCF/FCA (HY/SY) individuals, they are somewhat tapered and brownish with minimal edging, contrasting (especially by spring) with the darker greater coverts; on DCB/DCA (AHY/ASY) individuals, they are more rounded and darker with distinct grayish edging.
• Carefully consider the greater coverts - in basic plumage, the presence of a molt limit between darker inner feathers and unreplaced paler outer feathers indicates FCF (HY/SY), but note that uniformly fresh greater coverts occur in both DCB (AHY/ASY) and most FCF (HY/SY) birds. In alternate plumage, beware that most individuals have a mix of formative/basic and alternate feathers in the greater coverts; the only safe indicator for FCA (SY) is the presence of three generations of feathers among the greater coverts, with the outermost feather(s) notably older and duller than the others.
• Look at the back - it is bluish-gray on DCB/DCA (AHY/ASY) males (sometimes with a bit of brown in basic plumage), a mix of brown and blue-gray on DCB/DCA (AHY/ASY) females and FCF/FCA (HY/SY) males, and mostly brownish on FCF/FCA (HY/SY) females.
• Examine the uppertail coverts - they have broad black centres with mostly blue edging on DCB/DCA (AHY/ASY) males, moderately large black centres with a mix of brown and blue edging on DCB/DCA (AHY/ASY) females and FCF/FCA (HY/SY) males, and narrow black centres with mostly brown edging on FCF/FCA (HY/SY) females.
• Check the shape of the outer rectrices - on FCF/FCA (HY/SY) birds they are sometimes relatively narrow and pointed, while on DCB/DCA (AHY/ASY) birds they tend to be broader and more rounded, but relatively many intermediates occur.

Species account prepared by McGill Bird Observatory (2016). Last updated by Marcel Gahbauer (Mar 2022)