HIS BEAK AND TONGUE
HOW does a bird get along without a hand? He has to prepare food; to keep his feathers in order; to build the nest; to feed and take care of the young; and sometimes to fight other birds. How can all this be done without a hand?
[Ill.u.s.tration: FIG. 1.
Bill of Oriole.]
The beak is the only thing most birds have in place of a hand, and it is wonderful to see how many things they can do with it.
Orioles use it as a needle, in making the nest. With it they weave strips of soft bark or strings, back and forth, in and out, to make the firm pocket they hang on the elm-tree (see Fig. 1).
[Ill.u.s.tration: FIG. 2.
Bill of Woodp.e.c.k.e.r.]
A woodp.e.c.k.e.r"s beak is a chisel or pick, to cut a deep hole in a tree trunk for a nest (Fig. 2). With a nuthatch it is a hammer, to crack the nut he has wedged into a crevice in the bark so tightly it cannot slip.
[Ill.u.s.tration: WHITE-BREASTED NUTHATCH]
Some birds use the beak to dig in the ground, as the bank swallows, while the barn swallows make it a trowel, to carry and plaster mud (Fig.
3). All of them use it as a hand to feed themselves, and a brush and comb to dress their feathers.
[Ill.u.s.tration: FIG. 3. Bill of Swallow.]
Birds need to use the beak a good deal, because in most cases it grows like our finger-nails. If they did not keep it worn off, it would grow so long as to trouble them. Sometimes when a bird lives in a cage and does not use his bill, it grows so long that he can hardly pick up his food.
The woodc.o.c.k"s long beak is sensitive, so that he can feel the worms, deep in the mud where they live. Many waders and swimmers have beaks soft like leather.
[Ill.u.s.tration: FIG. 4. Bill of Hawk.]
You can tell by the shape of the beak how a bird lives, and what he eats. The strong, hooked beak of a hawk shows that he catches live animals to eat (Fig. 4). The long, narrow, sharp bill of a heron shows that he spears his prey, often under water.
The sharp-pointed bill of a warbler is to pick tiny insects and eggs out of blossoms, and from under leaves. The sharp-edged bill of a sparrow (Fig. 5) is to break open the hard sh.e.l.ls of seeds.
[Ill.u.s.tration: FIG. 5. Bill of Sparrow.]
The curious beak of a crossbill (Fig. 6) is to pick seeds out of pine cones.
[Ill.u.s.tration: FIG. 6. Bill of Crossbill.]
A duck"s wide beak, with a strainer at the edge, is to let water out while keeping food in. A spoon-shaped bill is to scoop up food, and a thin, flat one is to poke into narrow cracks.
Both parts of the beak, which take the place of our jaws, are called mandibles, upper and lower. Both of them can be moved, while we can move only our lower jaw.
Birds" tongues are as curious as their beaks. To all birds they take the place of a finger, as the beak takes the place of a hand, and they differ as much as the beaks from each other.
Insect eggs are very small, and often packed snugly into cracks and corners, and the birds who eat them have a brush on the tip of the tongue, which brushes an egg out of its hiding-place very easily.
The nuthatch picks his small grubs out of crevices in bark with the four-tined fork at the end of his tongue.
A hummingbird"s tongue can be used as a tube, to draw up the honey of flowers, or perhaps as a pair of tweezers, to pick out the tiny spiders that live there.
A woodp.e.c.k.e.r has barbs on his tongue, to spear insects hidden under the bark, as shown by Mr. Lucas (Fig. 7). It is said to be sticky also, to hold small ones, like ants.
The tongues of birds are of many shapes, but each one is fitted to its owner"s way of getting a living.
[Ill.u.s.tration: FIG. 7. Tip of Tongue of Downy Woodp.e.c.k.e.r.]
Because the tongue is often h.o.r.n.y, and they eat strange things, it is sometimes thought that birds have little sense of taste. But we cannot be sure of this, and we know they all have notions about their food.
Dr. Ward tells a story of some geese, which shows that they do not lack that sense. While sailing upon a river he noticed on the bank some geese, feeding on the rinds of watermelon, which they picked out of the garbage dumped there.
The rind, when taken out of the ma.s.s, was none too clean, being covered with mud and other dirt. When a goose found a piece to suit him, he took it up, carried it to the edge, and dropped it into the shallow water.
Then he stood and watched it till the running stream washed it clean, when he stepped into the water and quickly ate off the part he wanted.
XXIII
HIS EYES AND EARS
BIRDS" eyes are very different from ours. To begin with, they are round.
Then they are placed one on each side of the head, so that they can look two ways at once. Owls are the only birds who have eyes turned forward like ours.
Birds" eyes also are of many colors. Besides our common black, brown, blue, and gray, birds have light and dark green, bright red, pale and deep yellow and orange, even white.
They have, like us, two eyelids. But while we use the upper one to close our eyes, most birds use the lower one. They have also a third eyelid, inside the others, a thin, white sort of skin, that moves across the eye from side to side, and is called the "nict.i.tating membrane."
There are other ways in which birds" eyes differ from ours. The men who try to know exactly how birds are made have found out that birds" eyes make everything look much larger than it is, in other words, they are like magnifying gla.s.ses, or microscopes, so that a tiny insect egg, that we can hardly see, looks very big to a warbler.
Stranger still, when a bird is far off, his eyes are like telescopes.
That is, when a hawk is soaring about far above the earth, he can see a mouse on the ground as well as if he had a telescope to look through.
And the gulls who sail about over the sh.o.r.e, and follow steamers on sea voyages, can see small fish and tiny bits of bread thrown out by the pa.s.sengers, even when they are lost to us in the foam made by the vessel.
Mr. Frank Bolles had a pet barred owl, and used to take him out with him. He says that the bird"s sight was wonderful, better than his own aided by a strong gla.s.s. Many times the bird would see and watch a hawk so far off that Mr. Bolles with his gla.s.s could not see him until he came nearer, and then he looked no bigger than a dot against the sky.
There is a story told of some small birds migrating over the island of Heligoland, suddenly coming down in a flock on to a man"s garden, and beginning at once to work among the leaves as if they were feeding.
The owner of the garden knew they did not eat leaves, so he shot a few and found them stuffed with small caterpillars. Then he looked at the plants and found many more caterpillars, each in the curled-up end of a leaf. The insects could not be seen, yet the birds, while flying over, no doubt saw the curled leaves and knew they were there.
Such eyes must be of great use in helping birds to find their food, and to avoid their enemies. But think what giants we must look to them! It is no wonder they are afraid of us.
Perhaps even more useful to a bird than his eyes are his ears, though they are so nicely covered up by the feathers that we cannot see them.
The tufts of feathers that stand up on some owls" heads, and are called ears, are not ears at all, but merely decorations, like the crests of some birds and the long tail feathers of others.
But because they cannot be seen, we must not think birds have no ears; they have very good ones indeed. They can hear much better than we can.