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Mergus

Typical mergansers
Mergus serrator.jpg
Red-breasted merganser (Mergus serrator)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Subfamily: Merginae
Genus: Mergus
Linnaeus, 1758
Species

Mergus australis (extinct)
Mergus merganser
Mergus octosetaceus
Mergus serrator
Mergus squamatus


Mergus australis (extinct)
Mergus merganser
Mergus octosetaceus
Mergus serrator
Mergus squamatus

Mergus is the genus of the typical mergansers, fish-eating ducks in the seaduck subfamily (Merginae). The genus name is a Latin word used by Pliny and other Roman authors to refer to an unspecified waterbird.

The hooded merganser, often termed Mergus cucullatus, is not of this genus but closely related. The other "aberrant" merganser, the smew (Mergellus albellus), is phylogenetically closer to goldeneyes (Bucephala).

Although they are seaducks, most of the mergansers prefer riverine habitats, with only the red-breasted merganser being common at sea. These large fish-eaters typically have black-and-white, brown and/or green hues in their plumage, and most have somewhat shaggy crests. All have serrated edges to their long and thin bills that help them grip their prey. Along with the smew and hooded merganser, they are therefore often known as "sawbills". The goldeneyes, on the other hand, feed mainly on mollusks, and therefore have a more typical duck-bill.

Mergus are also classified as "divers" because they go completely under-water in looking for food. In other traits, however, the genera Mergus, Lophodytes, Mergellus, and Bucephala are very similar; uniquely among all Anseriformes, they do not have notches at the hind margin of their sternum, but holes surrounded by bone.


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Wikipedia

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