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Red-breasted Merganser | Mergus serrator
Middelste zaagbek | Serreta mediana
The Red-breasted Merganser is a slender fish-eater with a long thin red bill and a ragged crest. It breeds in northern North America and Eurasia and winters mainly at sea along coasts. In the Caribbean it is a winter visitor, fairly common in Cuba and scarcer to the south. In Cuba it is called pato serrucho.
Voice
Usually silent in winter. The female gives a hoarse grating krrr-krrr; the displaying male a soft cat-like yee-ow.
Recording: Stanislas Wroza — CC BY-NC-SA 4.0 · converted to mono · xeno-canto
Identification
51–64 cm, long and slender, with a thin red bill with fine serrations and a double, ragged crest on the back of the head. The male has a dark green head, a white collar, a rufous streaked breast with black and white patches at the side, a black back and grey flanks; the eye is red. Female and young birds are grey with a rusty head that blends into the pale neck without a sharp border. In winter the birds seen in the region are mostly females and young. In flight it looks elongated, with a white wing patch split by one or two black bars.
Confusion species
Female Hooded Merganser Lophodytes cucullatus is smaller and browner, with a broad fan-shaped crest and a dark bill with a yellow lower mandible. Common Merganser Mergus merganser, with no known records from the region, has in the female a sharp border between the rufous head and the white throat and neck. Grebes and cormorants, which also sit low in the water and dive, lack the red bill and have a different shape.
Habitat
Sheltered bays, shallow coastal waters, seagrass beds, saline lagoons and mangrove creeks; less often on fresh water. It dives for small fish and crustaceans, often in small groups that hunt together.
Where the bird is most at home, classified by the vegetation types of the Caribbean.
Range and movements
A fairly common winter visitor and passage migrant in Cuba, and a winter visitor in the Bahamas and the Turks and Caicos Islands. Scarcer in Jamaica, Hispaniola and the Cayman Islands; in Puerto Rico, where it is regarded as accidental, the Virgin Islands and the Lesser Antilles a rare visitor or vagrant. Outside the region it breeds in Alaska, Canada, Greenland, Iceland, northern Europe and northern Asia, and winters along the coasts of North America south to northern Mexico, and of Europe and East Asia.
- Resident
- Winter visitor (c. Apr–Sep)
- Passage (Mar–Apr, Oct–Nov)
- dark = core range, pale = thinly spread
How and when to look
Best in winter along the coasts of Cuba and the Bahamas, in sheltered bays and lagoons, where the birds sit low in the water and dive often. A small group hunting together often dives at the same moment.
Conservation status
Not threatened globally. In the Caribbean a winter visitor.
Scientific name
Mergus serrator | Linnaeus, 1758
Linnaeus described the species in 1758 and placed it straight away in the genus where it still stands. He introduced the genus Mergus in that same work. Mergus is the Latin word for an unidentified waterbird mentioned by Pliny the Elder and other authors; some have taken it to be a cormorant or Scopoli's shearwater. serrator is Latin for 'sawyer', from serra 'saw', after the saw-like teeth along the bill with which the bird grips slippery fish. The specimen the first description was based on came from Sweden.