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“With wingy speed outstrip the eastern wind,

And leave the breezes of the morn behind."-ADDISOX.

668. Why do eagles drive away their young ?

Because, as these birds subsist by prey, they would soon produce a famine among their race did many of them dwell in the same district.

Therefore, the old birds drive away their young at a certain age from their boundaries.

669. Why are the wings of eagles broad, and hollow in their under surfaces ?

Because the eagle, when in search of its prey, floats in the air until its keen eye discovers that of which it is in quest; by this peculiarity of structure, therefore, the wings can take a more powerful hold on the air, and the whole body is enabled to float with little labour.

670. Why are the wings of the eagle, though powerful, shorter than those of the falcon, both being birds of prey ?

Because falcons catch their prey while on the wing, and therefore have the faculty of rapid and uninterrupted flight; but the eagle strikes its victim to the ground, or the waters, and afterwards rises with it, thus requiring strengthin a greater degree than rapidity.

671. Why, in the eye of the falcon, crane, and other birds of piercing sight, has the flattened optic nerve one of its branches folded into numerous plaits ?

By this arrangement, the extent of surface is considerably augmented, and the powers of vision proportionally increased.

672. Why are the eyes of birds and animals who seek their prey by night, or in the dark, larger than those of other animals ?

Because the large eye of the nocturnal animal admitting more light, and taking in a wider field of view than a small one, enables the animal to find the object of its search more readily.

“ It was the owl that shriek'd, the fatal bellman, which gives the stern'st good night."-SHAKSPERE.

673. Animals that depend chiefly upon the eye, and especially if they be feeders in the night, or in places to which little light can come, invariably have the eyes very large. This is the case with owls, and other nocturnal birds. The same law is observed even in connexion with the inhabitants of the sea. The surface fishes usually have the eyes small; and they get gradually larger, till, when we come to those which inhabit the depths, and yet are active, feeding upon other fishes, their eyes are very large-of which we have an example in the star-gazers.

674. Why are the eyes of nocturnal birds placed nearer to each other than the eyes of birds which fly by day?

Because, with nocturnal birds, the design is that they should have the light concentrated in front of them, in order that they may avoid flying against obstacles, which, under a different arrangement, they would inevitably do in the darkness of the night.

But in birds that fly by day, their range being of greater extent, it is intended to render their vision effective over as great an area as possible, that they may command the expanse around them.

675. Why has the eye of the owl and other nocturnal birds a shining substance deposited at the bottom of the eyeball ?

Because this substance, by reflecting the rays of light, endows the eye with power to distinguish objects in the dark.

676. Why are owls enabled to turn their heads round in almost a complete circle without moving their bodies ?

The owl has been gifted with this capability in order to compensate for the absence of motion in the eye, the globe of which is immoveably fixed in its socket by a strong elastic hard cartilaginous case, in form of a truncated cone.

677. Why is the head of the owl so disproportionately large ?

This is partly due to the looseness of the plumage by which it is covered and is further caused by the existence, between the inner

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“ Ye solemn warblers of the gloomy night,

That rest in lightning-blasted oaks the day,
Thro' the black mantles take your slow-pac'd fight,

Rending the silent wood with shrieking lay.”—CHATTERTON.

and outer tables (or bony layers) of the skull, of a number of large cells, which communicate with the organ of hearing, and render that sense more acute.

678. We find in owls an external ear, or conch, which exists in no other birds; this is concealed by the feathers, which are arranged in a sort of hollow cone around it, and, in some species, it is covered with a sort of lid, which the bird has the power of opening or closing at pleasure.

679. Why do owls possess feeble powers of flight?

Because they are not intended to obtain their prey by swiftness of pursuit, but by the stealthiness of their approach ; and the remarkable powers of other functions are therefore counterbalanced by the comparative incapacity of this particular one.

680. From the nature of their food, which is chiefly the different species of mice and other small and destructive quadrupeds, of which they capture vast numbers, owls may be regarded as the most serviceable of wild birds; and those species which are of the greatest use are so far from timid or retiring in their manner, that they resort to farm-yards, barns, and other places, and perform their services even in spite of the persecutions which they meet with from the thoughtless.

681. Why is the plumage of nocturnal birds of prey tapered off to a fine and soft point ?

Because this structure enables them to glide noiselessly through the air, and even among the leaves and sprays of the thick forests, without disturbing their prey.

682. Why are the wings of the serpent-eater, or secretary bird, tipped with hard points ?

Because in attacking serpents, it covers its breast with one wing as a shield, to protect itself from the bite of the reptile, and strikes at his victim with the other—the two wings thus acting as a shield and spear. Then, after breaking the cranium with its beak, the

“ The hosts of birds, that wing the liquid air
Perch'd in the boughs, had nightly lodginge there."-DRYDEN.

bird devours the serpent. This is the manner in which large and venomous serpents are killed ; but the bird frequently swallows non-venomous snakes alive.

683. The secretary bird destroys serpents, rats, and vermin, and is on that account much esteemed in the southern parts of Africa, which abounds with venomous serpents, snakes, scorpions, and noxious reptiles, also with lizards of many descriptions; the land-tortoise, gryllæ, or locusts, in variety, abundance, and depredation equalling their destructive hosts in other countries. Barrow relates a very curious circumstance respecting living serpents in the stomach of one of these birds after death. An English gentleman, who held an official situation at the Cape, being out on a shooting party, killed a secretary bird, which he carried home with the intention of having an accurate drawing rade from it. He threw it on the floor of the balcony near the house, when, after it had remained some time, and been examined and tossed about, one of the company observed a large snake pushing open the beak, out of which he speedily crawled in perfect vigour, and free from any injury. On the supposition that others might be in the stomach, the bird was suspended by the legs, and presently a second made its appearence, as large and as lively as the first. The bird was afterwards open, when the stomach was found to contain seven dead snakes, with a half-digested mass of lizards, scorpions, scolopendræ, centipedes, and beetles.

ORDER II.-INCESSORES.

684. Why are the incessores so named ?

From their classification as perching birds : the word incessores being derived from insideo, to lie in ambush ; indicating that the proper habitat of the order, with its sub-orders, is a bush or tree.

685. They are also called passeres or passerine birds, from passer, "a sparrow," to which bird the greater number of incessores bear a strong resemblance. In all the true incessorial birds, the toes are three before and one behind. The adaptation of the foot to grasping or perching is evident from the situation of the hinder toe, which is invariably placed on the same level with those in front, and by which they are distinguished from the rasores (scrapers) and grallatores (waders). The toes are slender, flexible, and of moderate length; of which the foot of the canary affords a very good example. The incessores are much on the wing; their legs are therefore much less developed than those “ Better's the place, though homely and obscure,

Where we repose in safety and secure
Than where great birds with lordly talons sieze,
Not what they ought, but what their fancies please.”—DRAYTON.

organs. The male bird surpasses the female in size, plumage, and song; they live in pairs, and construct their nests in bushes, trees, &c., with wonderful art.

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The feet of birds present very distinctive marks for observation.

In most species the toes are four 1

in number, and in the majority of these three are directed forward, and one turned back. This is the case with the eagle, 1, and falcon,

2; the toes in these and other 3

birds of prey being pointed with long, curved, and sharp talons.

The woodpecker has two forward 5

and two backward toes, 3; so also has the parrot. The night-jar has three forward toes, one of which is extended to considerable length, 4. The swift has all toes forward, 5; it clings with them to walls and cliffs. Larks have the backward claw long and slender, 6.

The ostrich has only two toes 7; Domestic fowls, and others of the same

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7

the cassowary has three, all in front. family, have four toes, and a spur.

The order INCESSORES is by many naturalists divided into five sub-orders : 1. Dentirostres ; 2. Fissirostres ; 3. Conirostres ; 4. Tenuirostres; 5. Syndactyli.

Sub-Order 1.- Dentirostres.

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686. Why is the first sub-order named dentirostres ?

Dentirostres signifies tooth-billed: from dens, a “tooth,” and rostrum, a beak ;" this tribe of birds being characterised by having a notch and tooth-like process on each side of the margin of the upper mandible. This renders them capable of attacking other birds; and they are accordingly predacious. The shrike, or butcher-bird, is the most formidable specimen of the sub-order.

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