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tumbler is a bird of great powers of flight, and mounts to such an elevation, as sometimes to be scarcely visible; it can also continue on the wing for several hours together, a circumstance which gives it value in the eyes of many, who delight to watch the circular movements of a flock of these birds, in close array, soaring at a vast altitude.
The tumbler pigeon varies in colour, whence have arisen various distinctive appellations, as bald-headed tumblers, the head being white; and bearded tumblers either blue or black, with a white moustache or stripe, extending from the base of the beak. The head is small and round, the beak short, and spine-shaped, the iris a clear pearl-white, the chest full and broad, the neck rather short, but slender, and the general contour compact. This variety is kept in great abundance in London.
THE ALMOND OR ERMINE TUMBLER.-This variety, though derived from the ordinary tumbler, is not trained to flight, but is kept for its beauty, and the rich and varied admixture of its colours. It is much less than the common tumbler in size, and the beak and head are remarkably small; the plumage is variegated ; yellow, black, white and brown,
or gray, being intermingled in streaks or dashes. It is not until after several moults, that the perfect colours are attained.
The above list of varieties of the domestic pigeon contains all of any note; several others, indeed, might be enumerated, as the Leghorn, the Spanish, and the Friesland Runt, (the latter having all its feathers reverted,) the Lace, the Finniken, the Spot, etc., but they are seldom to be seen, nor is any value attached to them.
THE SWIMMING, OR NATATORIAL GROUP.
In the natatorial group, or order, we are presented with a vast assemblage of birds, more or less decidedly constructed for aquatic habits, and the more so the more exclusively they tenant the waters of the sea, inlets along coasts, the mouths of wide rivers and extensive lakes. Somė, indeed, are so exclusively formed for passing the period of their active existence, and for pursuing their prey in the water, that on the ground their movements are embarrassed and awkward in the extreme, and, in a few, the powers of flight are utterly abrogated. We are now pointing to extreme cases on the one part,
for there are others in which the powers of flight are wonderful, the water serving only as a reservoir of food, which is snatched on or near its surface, and as an occasional resting place, the bird floating buoyantly, till it soars into the air. As examples, we may adduce the terns, the gulls, the albatross, the petrels, etc., birds thickly plumed, and which, in pursuit of their prey, make only slight plunges into the sea, or skim it off from the rolling waves, and seldom settle, except for a few minutes.
Between these extreme links in the chain there are others of intermediate position, and among them is the family comprising ducks, swans, and geese.
We shall not attempt to enter into an analysis of the numerous sub-divisions, of this extensive family, (termed Anatida,) but only offer a few general observations.
In the ducks, swans, and geese,“ the body is more or less boat-shaped, and covered with dense plumage, there being an under-layer of down next the skin. The feathers repel the water, which runs off them.
The legs are placed considerably backwards, so as to render the support of the anterior part of the body apparently laborious, and from this cause and the contour of the limbs, their gait on the ground is waddling. The three anterior tocs are united by webs, but the posterior toe is free, yet often lobated, or paddle-shaped. The bill is large, and more or less depressed, sometimes very broad; both mandibles are covered with a sort of leathery skin abundantly supplied by nerves of touch ; at the base of the upper mandible there is a sort of cere, (in which the nostrils are placed,) in some more extensive than in others, and at the tip of the upper
mandible is a sort of flat incurved hard nail, (called dertrum.) Along the edges of each mandible extends a series of laminated processes, sometimes remarkably developed and in close array, these serve as strainers, enabling the bird to sift the ooze or mud through the beak, and retain worms, insects, and vegetable matters. The tongue is large, fleshy, sensitive, and furnišhed along its edges with filamentous pectinations, which aid the beak in the retention of food. The eyes are defended by a strong membrana nictitans, and both sight and hearing are acute. The voice is hoarse, harsh, and clanging: in many species, there is a sort of osseous drum at the lower portion of the windpipe, in some there are certain dilatations, and in others the windpipe makes singular loops or flexures before entering the cavity of the chest to merge into the lungs.
In a state of nature, the males and females pair, the young are hatched, covered with down, and soon take to the water under the guidance of their parents. With respect to food, it is very various ; some appear to be herbivorous, others feed equally upon animal and vegetable substances, and greedily devour slugs, caterpillars, and aquatic insects. Others live on crabs, and marine shellfish, which they dive with great skill to obtain.
Though these birds are aquatic in their habits, and swim well, yet some are much more so than others; the
grazes on corn lands and fields, is far less aquatic than the wild or even tame duck, and resorts to the water principally for safety. The cereopsis goose of Australia is still more decidedly terrestrial. On the other hand, some species, as the New Holland musk duck, the steamer, or racehorse duck of the Falkland isles, and others, are as aquatic as the divers (Colymbus.)
Most, if not all the anatidæ, in the northern hemisphere at least, are migratory, and associated in flocks perform at due times northward