T HE mother bird sits on the nest and keeps the eggs warm all the time that the little birds are growing inside. She never leaves them except to stretch herself and get food. Sometimes the father bird sits while she is away, or he brings food to her. Sometimes he only sings to her.
The first thing that the baby-birds do for themselves is to get out of the egg. When they are ready you may hear them crying "cheep, cheep" inside. Then they tap away at the big end with a little horny tip, which grows on the top of their beak, and the shell cracks, and out they come.
If you can catch a chicken as soon as it is out of the egg, you may see this horny tip. But you must be quick, for a chicken is a very active baby-bird. It runs about directly it is hatched, and the horny tip falls off.
The next thing young birds do is to open their beaks and cry for food. Some, like the chickens, ducks, and partridges come out with downy feathers all over them. These run about and get food for themselves. Their mother takes care of them, and they cuddle under her wing when she calls to them.
Others, like the pigeon, the sparrow, and the thrush, are naked, blind, and helpless when they are hatched. They cannot get out of the nest, and their parents have to feed them.
If you keep doves in a cage, or if you can climb up to the pigeon-boxes where the pigeons have their nests, you may learn a good deal by watching a baby pigeon.
The day it comes out of the egg its eyelids are tightly closed. It has only a few downy tufts on its naked body, so you can see its fleshy wing and feel the bones. Handle it carefully and notice that its wing has three joints, just like your arm. One at the shoulder (s) close to the body, one at the elbow (e), and one at the wrist (w).
As it lies in the nest, it draws its elbow back and touches its shoulder with its hand. Then the wing is shut. But if you take hold of the hand (h) gently, and pull the arm out straight, then the wing is open. This is just what a bird does when he stretches his wings to fly.
Now watch the little ones day by day. By degrees pimples come out all over the body. Then the middle of each pimple sinks in and some feathers peep out. The first feathers are quite limp. The little featherlets grow all round the stem like hairs on a cat's tail. These are the down feathers. There are not many on a young pigeon.
The next feathers are quite different. They are flat and much stiffer. The featherlets only grow on each side of the stem. They are tinted, and you can see now whether the pigeon is going to be white or coloured.
It is these "covering" feathers which are so beautiful in most birds. They do not grow all over the body. If you push back the feathers of a dead bird you will see that they grow in places only, and spread themselves over the rest.
Meanwhile the long tail and wing feathers have been growing. Those for the tip of the wing grow on the hand, those for the edge of the wing on the arm, between the wrist and the elbow, and above these, like tiles on a roof, grow the small feathers right up to the shoulder, making the wing round and firm.
Feel one of the long wing feathers. It has a strong quill down the middle, which tapers away at the end so that the feather will bend, Now try to pull the featherlets apart. You will find that they stick together, as if they were glued. This is because there are tiny hooks all along each little branch, by which it is hooked on to the next one. So when the wings beat the air, it cannot pass through them, especially as the small side of each feather lies over the broad side of the next one.
By this time the young pigeons will have opened their eyes. But though they can stand up, they are very weak, and take all their food from their mother.
Then about a month after coming out of the egg, they go to the edge of the pigeon-house and watch the other pigeons. From time to time they stretch out their wings, and flap them a little. As they flap them downwards, the air under the front of the wing cannot get away there, and is driven out behind just as water is driven by an oar when we row. But as they lift the wing up again the feathers turn so that the air can pass through. Therefore, as they flap their wings they raise themselves a little, and flutter to the next ledge, and at last they fly to the ground and begin to pick up food with their parents.
Compare a young pigeon and a young chicken. Examine the down feathers, covering feathers, and long quill feathers.