Common merganser
Mergus merganser
Identification Tips:
- Large, sleek diving duck
- Long, pointed bill with serrated edges
- Red bill is thick at base, tapering towards tip
- Sleek, tapered crest, more obvious on females than on males
- Brown eye
- White secondaries
- Immature similar to adult female, often with a less-distinct
chin patch
Adult male:
- Greenish-black head and upper neck
- White breast, flanks and belly
- Black back and upperwing coverts with white scapulars
- White secondary coverts crossed with indistinct dark bar
- Alternate plumage worn from fall through early summer
- Male in basic eclipse plumage similar to adult female
Adult female:
- Red-brown head meets pale breast in crisp line of division
- Well-defined white chin
- White breast and belly
- Pale gray body plumage
Similar species:
Adult male in alternate plumage is somewhat similar to male
Red-breasted Merganser but has white breast and flanks, and a less
obvious crest. Female, immature and eclipse male distinguished from
similarly-plumaged Red-breasted Mergansers by sharply-defined chin,
reddish head contrasting with white breast, paler
gray plumage, sleeker crest and larger bill. In winter, Common Mergansers,
unlike Red-breasted Mergansers, are generally found in freshwater habitats.