MERGUS, in ornithology, a genus of birds of the order of anseres; distinguished by having the beak of a cylindrical figure, and hooked at the extremities, and its denticulations of a subulated form.
1. The cucullatus, or crested diver of Catesby, has a globular crest, white on each side; and the body is brown above and white below. This elegant species inhabits North America. It appears at Hudson's Bay the end of May, and builds close to the lakes.—The nest is composed of grass, lined with feathers from the breast; the number of eggs from four to six. The young are yellow, and are fit to fly in July.—They all depart from thence in autumn. They appear at New York, and other parts as low as Virginia and Carolina, in November, where they frequent fresh-waters. They return to the north in March; and are called at Hudson's Bay Omyka sheep.
2. The merganser, or goosander, weighs four pounds: its length is two feet four inches; the breadth three feet four. The bill is three inches long, narrow, and finely toothed or serrated; the colour of that and of the irides is red. The dun-diver, or female, is less than the male: the head and upper part of the neck is ferruginous; the throat white: the feathers on the hind part are long, and form a pendent crest: the back, the coverts of the wings, and the tail, are of a deep ash-colour: the greater quill-feathers are black, the lesser white; the breast and middle of the belly are white, tinged with yellow. The goosander seems to prefer the more northern situations to those of the south, not being seen in the last except in very severe seasons. It continues the whole year in the Orkneys; and has been shot in the Hebrides in summer. It is common on the continent of Europe and Asia, but most so towards the north. It is found also in Iceland and Greenland, and breeds there, retiring southward in winter, at which time it is found about the lake Baikal. It is frequent in America; inhabits the province of New York in winter; retires from thence in April, probably to Hudson's Bay; and, if it be the bird called a Fisherman-duck, found also in Carolina.
3. The ferrator, or red-breasted merganser, weighs about two pounds: the length is one foot nine inches, the breadth two feet seven; the bill is three inches long; the lower mandible red; the upper dusky; the irides a purplish red: head and throat a fine changeable black and green: on the former a long pendent crest of the same colour; the tail short and brown; the legs orange-coloured. The head and upper part of the female are of a deep ruff-colour, and the tail ash-coloured. These birds are most frequent in the northern parts of Great Britain. They are observed to breed on Loch Mari, in the county of Ross, and in the isle of Ilay. The species is common in most parts of the north of Europe, on the continent; and as high as Iceland, where it is called Vatus-end: also in the Russian dominions, about the great rivers of Siberia, and the lake Baikal. It is likewise frequent in Greenland in the summer, where it breeds on the shores. The eggs are like those of a wild duck, but smaller and whiter. It dives well, and is very active in the water; but the Greenlanders often take it by darts thrown at it, especially in August, being the time when it is in moult. It is frequent in Newfoundland, and often appears at Hudson's Bay in large flocks, but is observed to be of a larger size there than in Europe. They generally come in pairs the beginning of June, as soon as the ice breaks up; make the nest soon after their arrival, chiefly on dry spots of ground in the islands, and lay from eight to thirteen white eggs, the size of those of a duck: the nest made of withered grass, and lined with the down of the breast. The young are of a dirty brown, like young goslings. They all depart south in October to the lakes, where they may have open water. They are known at Hudson's Bay by the name of Ais-fick.
4. The albellus, or smew, weighs about 34 ounces: the length 18 inches, the breadth 26; the bill is near two inches long, and of a lead colour; the head is adorned with a long crest, white above and black beneath: the head, neck, and whole under part of the body, are of a pure white; the tail is of a deep ash-colour, the legs a bluish grey. The female, or laugh diver, is less than the male: the back, the scapulars, and the tail, are dusky; the belly is white. The smew is seen in England only in winter, at which season it will sometimes be met with at the southern parts of it; as also in France, in the neighbourhood of Picardy, where it is called la Piette: similar to this, we have heard it called in Kent by the name of Maggie-diver. On the continent we find it as far south as Carniola; frequents also Iceland, at which place, or some other arctic region, it passes the summer; and where it in course breeds, probably along with the other Mergansers; as it has been observed to migrate, in company with those birds, several kinds of ducks, &c. in their course up the Wolga, in February. It also inhabits America, having been sent from New-York, where it is probably a migratory species, as in Europe.
5. The minutus, or redheaded smew, weighs about 15 ounces; the length one foot four inches, the breadth one foot eleven: the bill is of a lead colour: the head slightly crested, and of a ruff colour: the hind part of the neck is of a deep grey, the fore-part clouded with a lighter colour of the same kind: the back and tail are of a dusky ash-colour, the legs of a pale ash-colour.—It is a native of Europe. Birds of this genus (Mr Latham observes) "are in general not so well flavoured as those of the duck kind; yet we have often met with the last species in the London markets, and by some they are thought to be very little inferior to the wild duck; which last now and then partakes of the filby haut zou, a flavour not disagreeable to the palates of the connoisseurs in good eating."