Red-breasted Merganser

The Red-breasted Merganser (Mergus serrator) is a slender, medium-sized diving duck famous for its striking, wild appearance and remarkable flight speed. Belonging to the group colloquially known as "sawbills," this duck possesses a highly specialized bill lined with serrations designed to grip slippery, fast-moving prey. Unlike its cousin, the Common Merganser, which prefers freshwater rivers and lakes year-round, the Red-breasted Merganser is highly salt-tolerant and is most frequently observed on coastal saltwaters during the winter months.

To identify the Red-breasted Merganser in the field, focus on its distinctive silhouette and bill:

• Bill: Exceptionally long, thin, and bright orange-red, featuring sharp, backward-pointing serrations and a slight upward tilt.
• Crest: Both sexes display a wispy, double-pointed, shaggy crest at the back of the head, giving them a perpetually windswept appearance.
• Breeding Male: Instantly recognizable by a glossy dark green head (appearing black from a distance), a broad white collar, and a reddish-brown chest band flecked with dark spots. The flanks are finely patterned gray, and the iris is a striking, piercing red.
• Female & Non-breeding Male: Uniformly grayish-brown bodies with a cinnamon-brown head and neck. Crucially, the brown plumage on the neck blends gradually into the white of the breast, lacking a sharp division.
• Similar Species: Distinguish from the Common Merganser by noting the male's reddish breast band (Common males are solid white below) and the female's gradual head-to-neck transition (Common females show a highly distinct, abrupt cutoff line between brown and white on the neck).

The Red-breasted Merganser utilizes distinct habitats depending on the season:

• Breeding Grounds: Inhabits northern boreal forests and tundra regions across North America, northern Europe, and Asia. They build nests near freshwater lakes, fast-flowing rivers, and brackish coastal deltas.
• Wintering Range: Mostly coastal, occurring along both Atlantic and Pacific coastlines, as well as the Gulf of Mexico and the Great Lakes. They prefer sheltered saltwater bays, estuaries, lagoons, and coastlines where shallow waters host abundant baitfish.
• Migration: A medium-to-long distance migrant, traveling primarily along coastal routes or overland water networks to reach marine wintering grounds.

These active, agile ducks showcase several unique aquatic behaviors:

• Foraging: They dive underwater to pursue fish, propelling themselves primarily with their webbed feet. They often hunt cooperatively, forming synchronized lines that swim forward to herd schools of small fish into shallow water or coves.
• Flight: Highly capable flyers, they are among the fastest ducks in level flight. Because of their heavy bodies and rear-placed legs, they require a long, splashing running start across the surface of the water to take off.
• Courtship & Vocalizations: Mostly silent during the winter. During spring courtship, males perform elaborate displays, including shaking their heads, stretching their necks upward, and emitting low, rasping grunts or cat-like purring notes.
• Nesting: Females construct a well-concealed nest on the ground, often hidden beneath dense shrubs, tree roots, boulders, or driftwood close to the water's edge, lining it with soft down.