« ПредыдущаяПродолжить »
ORDER II. PASSERES.
(Perching Birds.) Though for the most part the birds of this Order are of smaller size than those of the others, yet the immense number of species included in it, which is about equal to that of all others together, renders it the most important of all. It is also considered by naturalists as the most typical; that is, as displaying the properties which distinguish a bird from other animals, developed in the greatest perfection. Great varieties of form and structure are found in a group so immense as this; so that but few positive characters can be assigned which are at the same time common to the whole, and peculiar to them. The power of grasping the branches and twigs of trees with the feet, and the habit of perching upon these, are prominent in the Order; the hind toe is always present, and the claws are not capable of being elevated, as in the birds of prey. The greater number of the species habitually dwell in woods and thickets. The power of flight exists throughout the Order in full perfection, and in some of its genera, as the Swifts and the Humming-birds, may be considered as at its greatest development. The beak varies greatly in form, but its general shape is that of a cone, more or less lengthened. In some of the genera which retain predaceous propensities, a trace of the tooth which marks the upper mandible of the Falcon, remains in a notch near the tip; a mark which is obliterated by imperceptible gradations. The food of the Passerine birds embraces a wide variety of substances, but yet the vast majority feed either upon insects or upon vegetable seeds; and in almost every instance these are procured by the beak alone, without the aid of the feet.
To this Order, with scarcely a single exception, belong the birds whose voices are uttered in notes of melody. Every one is acquainted with the song of a bird; and there are, probably, few whose hearts are not in some degree open to the sweet and soothing influence of its associations. To walk out on a sunny morning in early spring, and listen to th as he soars up invisibly into the bright sky, or to the broken whistle, so rich and mellow, of the blackbird, among the yet bare and leafless twigs of the grove; or, by and bye, when the forest has put on its verdure, to walk through its leafy bowers, when thousands of throats are pouring forth their sweet warblings around,—this is indeed delightful.
“ 'Tis pleasant, 'tis pleasant in greenwood-shade,
When the merle and the mavis are singing." The song of birds seems to be connected with the passion of love. In a wild state birds do not in general sing, except during the pairing season, when the trilling forth of their wild melodies appears to be designed to please and cheer their mates. Some naturalists think that the particular notes which constitute the distinctive melody, in any given species, are the result of imitation alone, being handed down by what we may call tradition; and that if a young bird were brought up without ever having heard the song of its species, it would be destitute of it.
It is in this Order, also, that we find the instinct of nest-building most perfectly displayed. The specimens of nests which are prepared, we can hardly say built, by other birds, are rude structures, consisting mostly of loose aggregations of rough materials with scarcely an attempt at construction. But very many of the Passerine birds build most elaborate and elegant structures, of which we may mention as instances, the compact felted nests of the Humming-bird, of the Goldfinch, and of the Bottle-tit, and the woven purses of the Orioles and the Starlings.
The study of this immense assemblage of species is facilitated by its sub-division into four Tribes, characterized by the varying form of the beak, and named respectively Fissirostres, Tenuirostres, Dentirostres, and Conirostres.
TRIBE I. FISSIROSTRES.
The beak in this Tribe is short, but broad, and more or less flattened horizontally, often hooked at the tip, with the mouth very deeply cleft : the upper mandible is not notched.
The feet are small and feeble. Most of the species feed on insects, which they capture on the wing, but one genus subsists on fishes.
The tropical regions are the principal home of the fissirostral birds; such species as reach to the temperate zone, are, for the most part, migratory
visitors, retiring on the approach of winter to more genial climes. Many of the species are distinguished for the brilliant hues which adorn their plumage.
The six Families of the Fissirostres are Caprimulgida, Hirundinida, Todida, Trogonida, Alcedinida, and Meropide.
FAMILY I. CAPRIMULGIDÆ.
The analogy between these birds and the Owls has been observed not only by naturalists, but even by the vulgar, as the common names of our native species, Fern Owl, Churn Owl, &c., indicate. Indeed, the nocturnal flight, the feathered feet, the large ears and eyes, as also the sort of disk that surrounds the face, and the saw-like edge of the first wing-quill, observable in some species, the downiness of the plumage, its sombre but varied hues, and their exquisitely mottled and pencilled arrangement, all form so many characters, which evidently point to the Nightjars as the connecting link between the Accipitrine and the Passerine Orders.
The Caprimulgidæ have the beak exceedingly small, but the gape enormous; its sides are for the most part furnished with long and stiff bristles, which point forwards, and the interior of the mouth is moistened with a glutinous secretion. All these provisions aid the capture of large insects in flight, which form the principal prey of these birds. The wings are long, and formed for powerful flight; the feet are very small, plumed to the toes, which are connected at the base by a membrane; even the hind toe, which is directed inwards, is thus joined to the inner toe. The claw of the middle toe, in most of the genera, is dilated on one side, and its edge is cut into regularly formed teeth, like those of a comb.
The voices of the Nightjars, like those of the Owls, are often harsh and uncouth; but their utterance frequently possesses a vibratory or quivering character that is peculiar. With a single exception, they are nocturnal in their activity. Their eggs are laid on the ground, with but a slight mat of loose materials in place of a nest. The species are widely spread ; and some of those which inhabit tropical countries have remarkable appendages to some of their feathers.