Smew

Overview

The Smew is a small, distinctive merganser native to northern Eurasia, breeding in forested wetlands and wintering on lakes and rivers further south. The male in breeding plumage is mostly white, giving a striking, almost pied appearance offset by a bold black patch through the eye and fine black lines tracing the back and flanks. Females and immatures, sometimes called "redheads" informally due to their chestnut cap, are gray-bodied with white cheeks and throat, offering a very different look from the male.

Feather Identification

• Overall male color: Predominantly white body feathering makes the male Smew stand out sharply from other mergansers, which tend toward darker overall tones.
• Eye patch: A bold black patch surrounds the eye, contrasting against the otherwise white head feathers.
• Back and flank lines: Fine black lines run along the back and sides, adding delicate patterning to the mostly white body.
• Crest: A small, rounded crest is present but less prominent than in the Hooded Merganser.
• Female head color: Females and immatures show a chestnut cap against white cheeks and throat, with a gray body quite different from the male's white plumage.

Plumage Notes

Breeding males are largely white with a black eye patch, fine black lines on the back and flanks, and a small crest. Females and immatures have a chestnut crown, white face and throat, and gray body plumage. Eclipse males resemble females but may retain traces of the black eye patch and some white in the wing. The species undergoes a complete molt after breeding. Juveniles resemble adult females, with young males gradually acquiring the mostly white adult plumage.

Habitat & Range

Smew breed in forested wetlands across northern Russia and Scandinavia, nesting in tree cavities near lakes and slow rivers. In winter, they move to lakes, rivers, and sheltered coastal waters across temperate Europe and Asia. The species is a rare vagrant outside its normal Eurasian range. It is migratory, shifting from northern breeding forests to more southern wintering waters each year.

Behavior & Field Notes

Smew dive to catch small fish and aquatic invertebrates in relatively shallow water. They nest in tree cavities, similar to the Hooded and Common Mergansers, and are often seen in small groups on wintering lakes. The species is generally quiet, with soft, low calls given mainly during courtship displays that involve head movements and short bursts of splashing. Flight is fast and agile on rapidly beating wings, typically low over the water surface.