The longest wings are seen on water birds, such as the petrel and the frigate-bird. The shortest, also, are found among water birds, those who swim more than they fly, as the auks.

All the feathers of the wing are named, and it will be well to remember that the long stiff quills are called _remiges_ or "rowers." These are firmly rooted in the flesh, and are the hardest to pull out. They are the most important to the safety of the bird.

Birds have also another use for their wings. They are a strong weapon to defend themselves, or to fight others. A large bird can give a severe blow with his wing, and when pigeons fight, it is said they hold up one wing to protect themselves while they strike at the enemy with the other.

Sometimes wings serve as musical instruments. Woodc.o.c.ks make whistling sounds with their wings as they fly, and mourning doves softly murmuring ones. Ruffed grouse produce with theirs a rolling drum-like effect, and others rattle theirs like castanets.

[Ill.u.s.tration: FIG. 13.

Tail of Ruffed Grouse.]

If wings are not used, they slowly get to be smaller and weaker, each generation having them more and more useless, till after a while they are of no use whatever, and the birds cannot fly at all. This has happened, it is supposed, to the ostrich family and to some birds living in the sea.

[Ill.u.s.tration: BROWN THRASHER]

[Ill.u.s.tration: FIG. 14.

Tail of Vireo.]

The tail of a bird is formed of an equal number of feathers in pairs, most often twelve. When spread they are the shape of a fan (Fig. 13), and when closed they lie over each other with the middle pair on top.

[Ill.u.s.tration: FIG. 15.

Tail of Swallow-tailed Kite.]

The tail feathers are not always of the same length, and that makes a difference in the shape of the end. Sometimes they are even (like Fig.

14), when the tail is said to be "square." Sometimes the middle feathers are a little longer than the outside ones, and then it is "rounded"

or "pointed." If the outside feathers are longest, the tail is "forked"

(Fig. 15).

The feathers of the tail are called _rectrices_, or "rudders," because they are supposed to be used to steer, or direct the bird's course in flying. But the tail is used also as a brake to check the speed in alighting.

The tail is used more than any other organ to express the emotions. Some birds, like the catbird and thrasher, keep it moving nearly all the time, jerking it this way and that, and tossing it upward.

[Ill.u.s.tration: FIG. 16.

Tail of Sapsucker.]

In woodp.e.c.k.e.rs and swifts the tail feathers are not soft at the end like others, but the stems or shafts project beyond the feathery part, and are stiff like the tail of a sapsucker (Fig. 16) or sharp like this of the chimney swift (Fig. 17). These birds use the tail as a prop to hold them against the tree trunk or chimney wall, and to help them in climbing.

[Ill.u.s.tration: FIG. 17.

Swift Tail.]

Tail feathers are not so strongly rooted as wing feathers, and are easily pulled out. Sometimes, when a man or boy tries to catch a bird by the tail, the bird will escape, leaving the tail in his hand.

XXVI

HIS DRESS

A BIRD'S whole dress is made of feathers, but the feathers are not all alike. There are, indeed, several kinds of feathers, and four of them are found on every bird. There are flight feathers, clothing feathers, downy feathers, thread feathers, and powder-down feathers.

Feathers of all kinds are made in the same way. All have, first, a quill, the h.o.r.n.y part next to the body; second, a shaft, the white part on which the barbs grow; third, the barbs, which grow out on each side of the shaft, and together are called the vane; fourth, the barbules, or little barbs, growing out of the barbs; and last, the barbicels, which grow on the barbules, and on the wings have the tiny hooks which hold them together.

But though feathers are made on the same pattern, they look very different. The wing and tail feathers are stiff and strong, and are called flight feathers, but those on the breast and body are called soft, and cling closely to keep the bird warm and dry. These are called the clothing feathers, because they clothe the bird.

Down feathers, which are almost always hidden under the clothing feathers, are, like their name, downy, and answer to our under-clothes.

Thread feathers grow among the clothing feathers, and are almost like hairs. It is these that the cook singes off the fowls.

Kingfishers who dive, and ducks who spend much time on the water, have very thick down under the feathers--like suits of very warm under-clothes--which keeps the water away from their bodies. Thus they can dive, or sit on the water hours at a time, and not feel wet at all.

Powder-down feathers grow on some herons and c.o.c.katoos. They are called by that name because the tip ends are continually breaking off like white dust. n.o.body knows their use.

Different from all these are the feathers called plumes, like the long, soft ostrich plumes we all know; the dainty little ones that stand straight up, and look as if the wind would blow them away; the long, showy feathers that the peac.o.c.k spreads with so much pride, or even the pretty, drooping ones in the c.o.c.k's tail.

These feathers are of no use for flight or for warmth, they rather hinder than help. They are for ornament, and there are many kinds among birds, all exquisitely beautiful. Nature has given to birds a more wonderful dress than to any other living creature.

It is with his feathers that a bird expresses his feelings. In anger he fluffs them out till he looks twice as big as usual; we have all seen a hen bristle up when a dog comes near her brood.

Nervousness or excitement is shown by jerking the wings and tail, and if a bird wishes to escape notice, he can make his plumage a perfect disguise. Mr. Bolles's pet owl would stretch himself up long and slim, with feathers hugging his body, when he looked so much like a broken branch of a tree that Mr. Bolles could hardly see him. And another owl that I heard of, when he was on the ground, would flatten himself and spread his plumage around, so that the eye could scarcely separate him from the dead leaves about him.

No one takes better care of his dress than a bird, and that is why it looks well for a year. Every day, with most birds, it is washed and carefully dried, each feather being pa.s.sed through the bill, and the whole thoroughly shaken out. At night one may often see robins and catbirds before going to bed, dressing their plumage and shaking off the day's dust.

Besides washing and drying the feathers, birds need oil to keep them in best condition. For this purpose they have a little "oil jug," a small gland over the tail, out of which, with the bill, they can squeeze a drop of oil. We often see ducks and geese oiling their feathers before a rain.

Water birds, who need a great deal of oil to keep out the wet, have the oil jug very large.

Birds seem to know perfectly well the beauty of their plumage. Not only do they try to show it off, as the peac.o.c.k when he spreads his tail, but they seem to feel shame when their feathers are injured or soiled. One white feather coming in where it does not belong will make a bird very unhappy. He will work and tug at it to pull it out, and often make himself actually ill over the trouble. I had a captive bird who died, I think, from worry and work over a wing feather which persisted in coming in white, and which he insisted on pulling out every time.

XXVII

DIFFERENT COLORED SUITS

A BIRD does not always wear the same colored dress, as I said in the chapter on moulting. A goldfinch, who through the summer wears a gay yellow coat, comes out in the fall in plain olive and black; and the scarlet tanager, who flourishes in the most brilliant red, changes to a quiet green in winter. Besides these, some birds wear at one season a spotted coat, and come out afterwards in one of plain colors.

Most of them change by moulting, as I explained, the old feathers dropping out and new ones of another color coming in; or, to speak exactly, the new ones growing out and pushing the old ones off on their tips. But some change color without moulting. All birds moult completely in the autumn, many moult partially in the spring, and some, as I said, change without moulting.

This last change of color is made partly by fading, and partly by breaking off the tips of the feathers, or what is called "abrasion."

This is a curious process. I told you something about it in chapter vii.

Certain feathers have edges different in color from the rest; as, for example, a black feather with tips of yellow. While the feathers are new and perfect, as they lie over each other like shingles on a roof, only the edges show, and these being yellow, the bird appears to be dressed in yellow. But the yellow tips are not so strong as the rest, and they break or wear off, or are pulled off in the spring. What is strange, they break exactly where the black begins. So as soon as the yellow is off, the black shows, and behold, the yellow bird suddenly becomes a black bird.