The place which the Pigeons ought to occupy in the zoological system has been a very fertile subject of dispute. Linnæus classed them with the Passeres; Buffon, Pennant, and Latham arrange them as an order by themselves; while Cuvier and others place them in the category of Gallinaceous Birds. The settlement of this question is, indeed, a matter of considerable difficulty, as the habits of the entire race are in many respects very peculiar. Like the Passerine Birds, they associate in pairs during the nuptial season, work together in the construction of their nest, and materially assist in the incubation of their eggs and the care of their progeny, which latter, blind and helpless when they are first hatched, are fed in the nest that forms their cradle, and which they never quit until fully fledged; indeed, for some time afterwards they are unable to supply their own wants, and depend entirely upon the assistance of their parents. The features in which they differ from the Passerine race are, however, equally well marked; these consist in their manner of drinking and of administering food to their young family, in the singularity of their caresses, in the nature of their plumage, and in their vocal capabilities. They neither sing nor utter any cry; their only voice in the adult state consists of a full, rolling sound, generally designated by the term "cooing." Other dissimilarities separate them from the Gallinaceous races, with which they have little in common, either in their instincts, their manner of life, or their mode of pairing. The Gallinæ are almost all of them polygamists, and the females, by laying numerous eggs, produce a covey at a single brood. Moreover, in temperate climates, this happens but once in the year. The Pigeons, on the contrary, are all of them strictly monogamous, and the female lays but two eggs for each sitting, although she has several broods. In the Gallinaceous tribes the male renders no assistance to the female, either in the construction of the nest or in the care of their progeny. The chickens are born with their eyesight perfect, and as soon as they escape from the egg-shell are able to run about, and procure for themselves their own food. The principal distinctive character of the Columbæ is furnished by the structure of the bill. The upper mandible consists of a horny apical portion, which is often of considerable length and strength, but its base is formed by a convex cartilaginous plate, in the anterior portion of which the nostrils are situated. The skin covering the cartilaginous portion is of a soft texture, very different from the rest of the bill. It is sometimes smooth, and clothed with a sort of scurf, but in other cases it is warty, or even developed into a fleshy wattle. This is especially the case in some domesticated varieties of the Pigeon. The Columbæ are provided with short tarsi and moderately long toes, all scutellated. The toes are four in number, three in front and one behind. The anterior toes are not united by a membrane at the base. The hinder toe is placed on the same plane with those in front, and the whole sole of the foot is formed of soft papillated pads, which are usually a good deal wider than the scutellated upper portion of the toes. The wings, which are generally long and pointed, contain ten primary quills, and the tail usually consists of twelve feathers, although in some cases there are sixteen. Another important character distinguishing these birds, as compared with the Gallinæ, is that their feathers are destitute of the plumules, or accessory plumes, which are greatly developed in Gallinaceous Birds. The form of the wing in Pigeons is sufficient to indicate that they are capable of powerful flight, and many of them are remarkable for the speed with which they traverse the air, especially when engaged in their migrations. Most of them are arboreal, and nestle in the holes of trees; others frequent rocks, but all perch with great facility; nevertheless, they generally seek their food upon the ground, and walk or run without difficulty. They are also remarkable for their mode of drinking, in which they differ from all other birds. The general practice of birds in drinking is to take up a small portion of water in the bill, and then, by raising the head, to allow it to run down into the throat. The Pigeons, on the contrary, dip their bills into the water, and hold them there till they have quenched their thirst. These birds are inhabitants of the warmer and temperate regions of the earth, but they are found in most abundance in hot climates, where, also, their plumage attains a brilliancy of which that of our native species gives us but an imperfect idea.
The FRUIT PIGEONS (Trerones) are recognisable by their compact body, short, thick beak, powerful, broad-soled, but short feet, moderate-sized wings, and short tail; the latter is composed of fourteen feathers, and is either slightly cuneiform or straight at its extremity. The plumage, in which green predominates, is always brilliant.
The members of this group inhabit the whole of India, the Malayan Peninsula, Australia, and Africa, and are usually seen in parties of variable number, perched upon fruit-trees. Their movements much resemble those of the Parrots, and their voice, unlike that of most of their congeners, is loud and sweet. Such species of Fruit Pigeons as inhabit India (and probably Africa) place their very loosely-constructed nest at the summit of a lofty tree, and lay two white eggs.
THE PARROT PIGEON.
The PARROT PIGEON (Phalacroteron Abyssinica), a beautiful species of the above group, is powerfully built, with long wings and a short tail; its beak, which is short and strong, has the base bare and the upper mandible hooked at its tip; the short tarsus is almost entirely covered with feathers, and the broad-soled foot furnished with small toes; the wing, in which the second quill is the longest, is pointed, and the tail straight at its extremity. The plumage of this beautiful bird is pale olive-green on the mantle and light yellow on the under side; the head, throat, and breast are greyish green, the shoulders of a rich deep red, the wing-covers of a blackish hue, broadly edged with pale yellow; the quills black, edged with a lighter shade; the dark grey tail is black upon the under portion, from the root to the centre, and from that point to the tip of a silver-grey; the purple-red iris is surrounded by a narrow blue ring; a bare patch which encircles the eye is blueish red, the cere of a dirty coral-red; the white beak is shaded with blue, and tipped with pale red; the foot is deep orange-yellow. The length of this species is twelve and its breadth twenty-one inches; the wing measures six inches and three-quarters, and the tail four inches and a quarter. The female is somewhat smaller in size, but closely resembles her mate in the coloration of the plumage.
This Pigeon has been met with in Great Namaqua Land, Western Africa, and Abyssinia. Temminck informs us that it frequents the settlements of the traders, and is constantly to be seen perching perfectly motionless upon the trees during the heat of the day; at the approach of the rainy season, he tells us, it consorts with others of its species in large flocks, and wanders forth to more southern portions of the continent: our own experience would, however, lead us to condemn the latter statement as erroneous, and, indeed, all recent observations on this point prove that this bird does not migrate. Lofty mimosa-trees, surrounded by bushes of Christ's-thorn, and interlaced with the streaming tendrils of the cissus, are the favourite resorts of such of these birds as inhabit regions where those trees are abundant, while such as occupy the mountain-valleys seek shelter amid the luxuriant foliage of the tamarind-tree, or upon the well-covered branches of the lofty sycamore. Occasionally this species is seen living in pairs, but most usually in small parties of from eight to twenty birds. Even when thus associated, it is easy to distinguish the different couples, as the males constantly perch and fly close to their mates, towards whom they exhibit the utmost tenderness, endeavouring to excite their attention and admiration by agitating their wings, and caressing and tending them with all the devotion exhibited by the Parrot for its mate. The flight of these Pigeons is rapid, and accompanied by a harsh, shrill sound, produced by the violent motion of the wings as they cleave the air. The voice is very unpleasing. Such of these birds as we observed did not utter the cooing note common to many of their congeners. The stomachs of those we shot contained berries of various kinds. Le Vaillant informs us that the Parrot Pigeon deposits her eggs in a bed of moss and dry leaves within a hollow tree, but this statement we believe to be erroneous. Owing to the extreme timidity of these birds, it is exceedingly difficult to obtain specimens.
The DOVES (Columbæ) are distinguishable from the above group by the peculiar form of their delicate, moderate-sized beak, which is covered with a cere at its base, is slightly vaulted, and has a hard, sharp tip. The comparatively high, slender foot is well adapted for walking firmly on the ground; the tail, composed of twelve feathers, is either rounded or straight at its extremity, and the plumage not remarkable for its brilliancy. The members of this group occupy all parts of the globe, Europe being particularly rich in species.
THE RING-DOVE, WOOD PIGEON, OR CUSHAT.