HOW BABY BIRDS ARE FED.
Some of the baby birds are nurslings, like the lambs and colts. They are dependent upon what the parent birds first eat and digest. Others eat just what the old birds do from the start. Only you will notice that the mother bird pounds and bruises the food she gives to her young, tapping it on the edge of the nest or on a twig or the ground until it is soft enough for the birds to swallow without danger of scratching their tender throats.
Linnets, pigeons, humming-birds, and some of the finches, are nurslings. The food is prepared for them by the parent birds, and the young are fed by the old bird's bill. We imagine that the bill of the parent bird is the nursing-bottle. The old birds first eat food themselves, and then work it over in their crops into a sort of paste or milky fluid. Then, when the meal is all ready, they alight on the edge of the nest and feed the babies. We have seen humming-bird mothers feed the babies while poised on their wings above the nest.
Perhaps there are four or five finches all clamoring for breakfast, crying, and stretching their little necks up as high as possible. The old bird on the edge of the nest looks at the open mouths of all her babies, and begins at the one she thinks is the hungriest. She puts the nursing-bottle, which is her bill, far down the throat of the nursling, clinging fast to the nest or twig with her toes, and moving her bill up and down, her own throat throbbing all the while.
We once saw a humming-bird feed one of her young ones and then fly away. During her absence the little birds changed places in the nest, turning completely around. When the mother came back to finish giving them their breakfast, she made no mistake, but fed the hungry one, though both had their bills wide open.
When the mother has fed one child as much as she thinks is its share, she turns to the next open mouth. In this way she nurses the whole cradleful, who seem never to be satisfied.
Humming-Bird feeding her Young.
We have seen no "runts" or dwarf birds in a family, as are sometimes seen in a nest of pigs or puppies. The parent birds seem to understand, and to see that each baby has its proper share and not a crumb more. They do not love one better than another.
Some birds keep on nursing their young long after we think the lazy children are large enough to be looking out for themselves. It would be no better than they deserve if they had to go hungry sometimes. We think they often must get very hungry before they have learned to work for their board. This is all right, for if the parents kept on supporting them, what useless creatures they would be!