Blue-winged Warbler - Vermivora cyanoptera

Blue-winged Warbler has a partial preformative molt; prealternate molts are generally absent or at most limited to head feathers. Both age and sex can usually be easily determined by plumage throughout the year.

Blue-winged Warbler frequently hybridizes with Golden-winged Warbler; the appearance of hybrids can be somewhat variable, but the general principles of ageing and sexing can usually be applied.

Quick tips

• Examine the primary coverts - on DCB/DCU (AHY/ASY) individuals they are dark gray with pale edging, while on FCF/FCU (HY/SY) birds they are brownish and without edging.
• Look at the crown and nape - on DCB/DCU (AHY/ASY) males the bright yellow crown contrasts sharply with the greenish nape, on FCF/FCU (HY/SY) males and DCB/DCU (AHY/ASY) females the yellow crown fades in to the greenish nape, and on FCF/FCU (HY/SY) females the greenish-yellow crown shows little contrast with the nape.
• Consider the eye line - on DCB/DCU (AHY/ASY) males it is bold black, on FCF/FCU (HY/SY) males and DCB/DCU (AHY/ASY) females it is blackish, and on FCF/FCU (HY/SY) females it is dark gray.
• Examine the rectrices - on FCF/FCU (HY/SY) birds they are relatively narrow and tapered to a point with relatively small white patches on the outer feathers, while on DCB/DCU (AHY/ASY) birds they are more broad and rounded toward the tip, with larger white patches.

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