Waterfowl

Most of the farm ducks in the world can trace their ancestry to mallards. The rest of the farm ducks in the world are derived from the Muscovy Duck (Cairina moschata), which is distinguished by turkey-like fleshy patches around its eyes.)

Muscovy ducks and Rouen (pronounced roan) ducks can inter-breed but the offspring will be infertile. src

Mallards are exceptionally fast flyers for their size: fly to (burst) speeds of 65 mph; live up to 29 years in age (delHoyo, J., A. Elliot, and J. Sargatal, eds. 1992. Handbook of Birds of the World, Vol. 1. Barcelona: Lynx Edicions.). src1 src2 src3 The world's fastest birds Longevity Records

Unlike other dabblers, gadwall lack the metallic speculums, and instead both sexes display a white speculum quite visible in flight. src

Adult Male.

Bill nearly as long as the head, deeper than broad at the base, depressed towards the end, the sides parallel, the tip rounded. Upper mandible with the frontal angles short and obtuse, the dorsal line at first sloping, then slightly concave and direct, the ridge broad and flat at the base, then broadly convex, the edges soft, with about fifty internal lamellae, the unguis roundish, curved abruptly at the end. Nostrils sub-basal, lateral, rather small, oblong, pervious. Lower mandible flattened, its angle very long and narrow, the dorsal line very short, slightly convex, the edges soft, with about sixty lamellae.

Head of moderate size, oblong, compressed. Neck rather long, slender. Body elongated, slightly depressed. Feet very short; tibia bare for about a quarter of an inch; tarsus very short, compressed, anteriorly with two series of scutella, the outer shorter, the rest covered with reticulated angular scales; toes obliquely scutellate above; first very small, free, with a narrow membrane beneath; third longest, fourth considerably shorter, second shorter than fourth, their connecting webs entire, on the edge crenate; the second or inner toe with a membranous margin. Claws small, slightly arched, compressed, rather acute, the hind one very small and more curved, that of the middle toe with an inner sharp edge.

Plumage dense, soft, blended. Feathers of the head short, of the occiput and nape a little elongated, of the lower parts glossy, with the extremities of the filaments stiffish. Wings rather long, little curved, pointed; the first quill longest, the rest rapidly graduated; secondaries very broad, but pointed, the inner much elongated, and tapering to a point. The tips of the filaments of the outer web of the first primary are separated and curved a little forwards. Tail short, rounded, of sixteen strong pointed feathers, of which the iniddle pair project considerably.

Bill bluish-black. Iris reddish-hazel. Feet dull orange-yellow, claws brownish-black, webs dusky. Head light yellowish-red, the upper part and nape much darker and barred with dusky; the rest dotted with the same. The lower part of the neck, the sides of the body, the fore part of the back, and the outer scapulars, undulated with dusky and yellowish-white, the bands much larger and semicircular on the fore part of the neck and breast; the latter white, the abdomen faintly and minutely undulated with brownish-grey; the elongated scapulars brownish-grey, broadly margined with brownish-red; the hind part of the back brownish-black; the rump all round, and the upper and lower tail-coverts, bluish-black. The anterior smaller wing-coverts are light grey, undulated with dusky, the middle coverts of a deep rich chestnut-red; primary coverts brownish-grey, outer secondary coverts darker and tinged with chestnut, the rest black, excepting the inner, which are grey. Primaries and inner elongated secondaries brownish-grey, of which colour also are the inner webs of the rest, part of the outer webs of five of the outer black, and their terminal margins white, of which colour are the whole outer webs of the three next to the inner elongated quills. Tail brownish-grey, the feathers margined with paler.

Length to end of tail 21 3/4 inches, to end of wings 19, to end of claws 23 1/4; extent of wings 35; bill along the ridge 1 3/4, along the edge of lower mandible 1 7/8; wing from flexure 11; tail 4 3/8; tarsus 1 1/2; hind toe and claw second toe 1 5/8, its claw 4/12; third toe 1 7/8, its claw 4/12; outer toe 1 (7 1/2)/12, its claw 8/12. Weight 1 lb. 10 oz.

Adult Female.

The female is considerably smaller. Bill dusky along the ridge, dull yellowish-orange on the sides. Iris hazel. Feet of a fainter tint than in the male. Upper part of head brownish-black, the feathers edged with light reddish-brown; a streak over the eye, the cheeks, the upper part of the neck all round, light yellowish-red tinged with grey, and marked with small longitudinal dusky streaks, which are fainter on the throat, that part being greyish-white; the rest of the neck, the sides, all the upper parts and the lower rump feathers brownish-black, broadly margined with yellowish-red. Wing-coverts brownish-grey, edged with paler; the wing otherwise as in the male, but the speculum fainter. Tail-feathers and their coverts dusky, laterally obliquely indented with pale brownish-red, and margined with reddish-white.

Length to end of tail 19 1/4 inches, to end of wings 18 3/4, to end of claws 19 1/2; extent of wings 31; wing from flexure 8 1/4; tail 3 3/4; tarsus 1 (4 1/2)/12; middle toe 1 (9 1/2)/12, its claw 4/12.

In a male, the roof of the mouth is deeply concave, with a prominent median ridge, and oblique grooves toward the end. The tongue is 1 inch 10 twelfths long, fleshy, with a deep longitudinal groove, two lateral series of filaments, and a thin broadly rounded tip, as in other Ducks. The oesophagus, Fig. 1 [a, b], is 10 1/2 inches long, 5 twelfths in diameter for about four inches, then enlarged to 10 twelfths, and again contracted as it enters the thorax. The proventriculus, [b b], is 1 inch and 2 twelfths long, its greatest diameter 8 twelfths. The stomach, [c d e], is a very large and powerful gizzard, of an elliptical form, compressed, 1 inch and 9 twelfths long, 2 inches in its greatest breadth, or in the direction of the lateral muscles, of which the right, [c], is 10 twelfths thick, the left, [d], 9 twelfths. The epithelium is thick and rugous; much thickened and forming two roundish, flat or slightly concave grinding surfaces, opposite the muscles. The intestine, [e f g], is 6 feet 10 inches long, wide, its diameter for 2 feet being 4 1/2 twelfths, towards the rectum enlarging to 6 twelfths. It forms first a very long duodenal curve, [c e f g], and is then convoluted or coiled in numerous folds. The rectum is 5 1/4 inches long; the coeca 11 inches, their greatest diameter 6 twelfths, for 2 inches at the commencement 2 twelfths, towards the end 2 1/2 twelfths, their extremity rounded.

The trachea, [h], is 7 1/2 inches long; its diameter at the upper part 4 twelfths, gradually diminishing to 3 1/2 twelfths; it then enlarges to 5 twelfths, and contracts to 3 1/2 twelfths at the commencement of the dilatation of the inferior larynx, which is extremely similar to that of the Widgeon, but larger; there being an enlargement, [i], formed by a number of the lower rings united, and to the left side a rounded bony tympanum [j]; the greatest transverse diameter of this part, from [i] to [j], is 1 inch 1 twelfth. The bronchi, [k k], are of moderate size, covered with a dense layer of adipose matter.
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color of hazel eyes: light brownish with green at the bottom & darker toward the top.

Red-breasted Merganser - the fastest duck : max. recorded speed is 129 km/h (80 mph). The world's fastest birds

max. recorded speed of level flight in mph: Red-breasted Merganser (80); Canvasback (72); Eider duck (70); Teal (68); Mallard & Pintail (65).

The fastest duck ever recorded was a Red-breasted Merganser that attained a top airspeed of 100 mph while being pursued by an airplane. src

It is the fastest duck clocked in the 70's. But now it is not anymore. According to the popular facts and figures website, planet101.com, the fastest waterfowl species in flight is the Asian Spur-winged Goose (距翅雁), which has been clocked at 88 mph. src1

Unlike other waterfowl, the Long-tailed Duck wears its Alternate Plumage only in the winter. It gets its Basic Plumage in the spring and wears it for the breeding season. Most other ducks (e.g., Mallard) wear the non-breeding plumage only for a short period in the late summer.

Under the Humphrey-Parkes nomenclature, the main adult plumage, especially when it is produced by a complete molt, is called basic plumage. In most birds (e.g., Cattle Egret), the non-breeding plumage, which is worn longer than the breeding plumage, is known as the basic plumage. In birds that molt only once a year, the regular and only plumage is known as basic plumage. So, Cattle Egret (Basic Plumage = non-breeding plumage, less colorful), Mallard (Basic Plumage = breeding plumage; the Eclipse Plumage is an Alternate Plumage? or Supplemental Plumage?). Basic Plumage or not is determined by the length of time, not by more colorful / brighter or not, not by during breeding season or not. And Basic Plumage (without numbering) is usually to describe fully grown adults, ready for breeding. Juvenile Plumage is another story. For birds that do not completely molt into full adult plumage the first time, a numbering system is used to signify which plumage it is in. For example, for the first time a bird enters basic plumage, the plumage is known as first basic plumage; the second, second basic plumage. The numbers are dropped after a bird achieves its full adult plumage. Though, a modified HP system is used in Steve Howell's book on Molt and it is slightly different from here. And the term "plumage" and "aspect" are defined accordingly.

A unique small duck, readily identifiable by the male's bluish bill (in breeding plumage), white face, and long, stiff, upright black tail. Ruddy Ducks are often reluctant to fly, and when disturbed, often will sink below the surface and swim away underwater like a grebe rather than fly away. They are nearly incapable of walking on land, with legs and feet set very far back on the body. Ruddy Ducks are generally relatively tame, making the species susceptible to hunting pressures.

Habitat: Breeds on freshwater ponds and lakes with marshy borders. Many winter along coastlines in shallow bays and estuaries, but some may be found inland where open water is available.

Diet: Seeds, other plant material including roots and leaves, aquatic insects and their larvae, crustaceans, mollusks, occasionally small fish.

Behavior: Forages by diving and swimming underwater. It uses its bill to pluck mud from the lake bottom, straining the mud to obtain food items contained within.

Note: (1) They are strong fliers and make the long migration from their northern range in Alaska and Canada to their over wintering grounds along the U.S. gulf coasts south to mid Mexico. (src)

Adult Male.

Bill nearly as long as the head, deeper than broad at the base, depressed towards the end, the sides nearly parallel, the tip rounded. Upper mandible with the frontal angles short and obtuse, the dorsal line at first sloping, then concave, at the end decurved, the ridge broad and flat at the base, then broadly convex, the edges soft, with about fifty-five internal lamellae, the unguis obovate, curved abruptly at the end. Nostrils sub-basal, lateral, near the ride, oblong, pervious. Lower mandible flattened, its angle very long and rather narrow, the dorsal line very short, slightly convex, the edges soft, with about seventy lamellae.

Head of moderate size, oblong, compressed. Neck rather long, slender. Body elongated and slightly depressed. Feet very short; tibia bare for about a quarter of an inch; tarsus very short, compressed, anteriorly with two series of scutella, the outer shorter, the rest covered with reticulated annular scales; toes obliquely scutellate above; first very small, free, with a narrow membrane beneath; third longest, fourth considerably shorter, second shorter than fourth; their connecting webs entire, on the edge crenate; the second or inner toe with a membranous margin. Claws small, slightly arched, compressed, rather acute; the hind one very small and more curved, that of the middle toe curved outwards, and having the inner edge dilated.

Plumage dense, soft, blended. Feathers of the head and upper neck oblong, small, those along the crown and occiput longer; of the lower parts ovate, glossy, with the extremities of the filaments stiffish. Wings rather long, little curved, narrow, pointed; the first quill longest, the next scarcely shorter, the rest rapidly graduated; secondaries very short, broad, obliquely rounded; the inner elongated and tapering; the tips of the filaments of the outer web of the first primary are separated and curved a little outwards. Tail short, rounded and pointed, of sixteen feathers, of which the middle pair are more pointed and project considerably.

Bill light greyish-blue, with the extremity including the unguis, and a portion of the margins, black. Iris hazel. Feet light bluish-grey, the webs darker, the claws dusky. The upper part of the head is white, more or less mottled with dusky on its sides; the loral space and cheeks reddish-white, dotted with greenish-black; a broad band from the eye to behind the occiput deep green. The lower part of the hind neck, the scapulars, and the fore part of the back, are minutely transversely undulated with brownish-black and light brownish-red; the hind part similarly undulated with blackish-brown and greyish-white. The smaller wing-coverts are brownish-grey; the primary quills and coverts dark greyish-brown; the secondary coverts white, tipped with black. The speculum is duck-green anteriorly, bounded by the black tips of the secondary coverts, black behind, internally black, with white streaks, the inner elongated secondaries having their outer webs black, margined with white, their inner webs brownish-grey. The tail feathers are light brownish-grey. The throat is brownish-black; the lower part of the neck in front, and the fore part of the breast, light brownish-red; the breast, belly, and sides of the rump, white; the sides of the body finely undulated with white and dusky; the rump beneath and the lower tail-coverts black.

Length to end of tail 20 1/2 inches, to end of claws 21; extent of wings 34 1/2; bill to frontal processes 1 (7 1/2)/12, along the edge of lower mandible 1 7/12; wing from flexure 11; tail 4 1/2; tarsus 1 7/12; hind toe 4/12, its claw middle toe 1 8/12; its claw (4 1/2)/12. Weight 1 lb. 14 oz.

Adult Female.

The female is considerably smaller. The bill, feet, and iris are coloured as in the male. The head and upper part of the neck all round, are white or reddish-white, longitudinally streaked with brownish-black, the top of the head transversely barred; the lower part of the neck in front and behind, the fore part of the back, and the scapulars, are blackish-brown, the feathers broadly margined with brownish-red, and barred with the same, the bars on the back narrow; the hind part of the back dusky; the upper tail-coverts barred with white. The wings are greyish-brown; the secondary coverts tipped with white; the secondary quills are brownish-black, the inner greyish-brown, all margined with white. The tail-feathers are greyish-brown, margined with white. All the lower parts are white, excepting the feathers of the sides, and under the tail, which are broadly barred with dusky and light reddish-brown.

Length to end of tail 18 inches, to end of claws 19 1/2; extent of wings 30; bill along the ridge 1 6/12; wing from flexure 9 8/12; tail 3 9/12; tarsus 1 6/12; middle toe 1 9/12, its claw 3/12. Weight 1 lb. 5 oz.

A very great diversity of colouring exists in this species, which, however, is not yet properly understood. Although males are often found as described above, and as represented in the plate, others have a very different appearance. Thus, an individual shot at the mouth of the Mississippi, in the beginning of April 1837, has the head and neck brownish-orange, the feathers all minutely tipped with dark green, the lower fore neck lilac; all the upper parts finely undulated with white and dusky, as are the sides; the wing-coverts light brownish-grey; the other parts as described above, but the upper tail-coverts black at the end. In some individuals the top of the head is reddish-white, in others light red, in others pure white; in some, most of the smaller wing-coverts are white, in others grey or brownish-grey; in some the throat is whitish, in others black. These differences, no doubt, depend upon age and season.

The American Widgeon has been considered distinct from the European; not on account of any difference in size or form, or texture of plumage, but because it has in certain stages a green band on the side of the head, which the European bird is said not to have. The mirror is the same in both; the wing-coverts are white or grey in both; the crown is white, or cream-coloured, or orange-brown, in both; but in the European the head and neck are described as reddish-chestnut, and in the American as yellowish-white. Now, in fact, American birds sometimes have the head and neck red, and European birds sometimes have the green streak on the side of the head. In short, on comparing specimens from America, with others from India and Norway, I cannot perceive any essential difference. At the same time, not having traced our Widgeon through all its gradations, and being equally unacquainted with all those of the European and Asiatic Widgeon, I cannot positively affirm that Anas Americana is identical with Anas Penelope.

北极熊长期来被人们认为是耐寒动物的象征。在北极的"居民"中是否还有比他更耐寒的呢？

不久前，挪威科学家对北极地区的动物作了一次耐寒的试验。结果证明，耐寒冠军的荣誉应归于北极鸭 (Arctic ducks)，而不是北极白熊。因为北极鸭能经受零下110℃寒冷的考验，其次是海豹，然后才轮到白熊。白熊只能忍受零下80℃的考验。

北极鸭之所以能耐严寒，是因为它的羽毛下游一层细毛绒，想毛毯一样裹在身上，所以能保温御寒。中年栖息在北极地带的鸭，长这一身黑白双色的丰满羽毛，一般体重为五六千克。北极鸭在雪地上睡眠时，既不俯卧，又不卧躺在雪地上，而是单脚独立，另一只脚缩藏于腹，累了再换一只，依次轮换。

本文来源于贝壳小窝之最网( http://www.leebico.com/zhizui/ ) 原文链接：http://www.leebico.com/zhizui/new.asp?id=3246

而企鹅在南极达到最低温度零下89℃时还活的好好的呢。据测试企鹅能承受的最低温度也只是零下100℃左右。

尼日利亚蝇和喜马拉雅山上的水熊虫都能在接近绝对最低温度 --- 零下273摄氏度的液氧中生活那么几分钟，零下一百来度的时候那更是如鱼得水，无拘无束。那么就是它们[是最耐寒的物种 ]了吧？除非有的动物永远都冻不死。
没错！有的动物就是永远都冻不死 --- 那就是极地冰虫。 src

Snowy Owls have been observed in temperatures that are 80 degrees below zero. Out of the roughly 10,000 different bird species in the world, only the Adele Penguins of Antarctica have feathers that provide better insulation than the ones on a Snowy Owl. And as opposed to the well insulated but bare foot ducks, these owls have thick feathers covering their legs, their feet and even their beaks. Any birds that can survive 80 below zero would have to be tough and rugged, and Snowy Owls certainly meet these criteria. src

Unfortunately for the ducks, they don't have any down on their legs and feet. As a result, they have to spend the entire winter totally barefoot. To offset the lack of having warm shoes or even leg warmers left over from the 80s, ducks have evolved a less fashionable option. The blood moving to and from their feet circulates in what biologists call a "countercurrent." ... ...

The other reason ducks can run around barefoot was ... They have ... "thin, little feet." Their feet are thin because they contain few muscles or soft tissue. Long tendons control their feet while most of their muscles are higher up in the legs, kept nice and warm by feathers. All of this means very little blood is needed to keep the feet functioning. It is estimated that as little as 5% of a duck's body heat is lost through its feet. And don't forget that ducks have the ability to withdraw their feet and keep one or both tucked in their feathers, thus further cutting their heat loss. src