There, too, are the common crow blackbirds. They come in the spring in crowds, and when it is time to make nests, they find some grove or clump of trees that suits them, and all of them build their nests close together. Often there are two or three on one tree, like a bird city. There they live and rear their little ones, and it is said they never quarrel.
Then there are the birds who get their food from the sea, such as penguins. These birds live in big cities, of many thousand nests. They go to an island where no people live, and build on the ground, or on rocks, or anywhere.
Sometimes they are so near together one can hardly walk without stepping on them. How each mother can tell her own, it is hard to see. They live very happily together, and if a mother is killed, so that her little ones are left orphans, one of the neighbors will adopt them all, and feed and bring them up with her own.
Some of these birds do not even take the trouble to make a nest. They put the eggs anywhere on the sand or earth.
Some one, Mr. Brehm, I think, tells a pretty story about a certain kind of duck who rears two broods every season. After the ducklings of the first brood have learned to take care of themselves, they go about together, getting their food and sailing on the water in a little party, while their parents are hatching the second brood. But when the younger ones are big enough, they are led to the water, and at once their elder brothers and sisters join them. They all swim around together, the youngest in the middle of the group, where they are protected and fed by the elder brood as well as by the parents, a lovely and united little family.
XVIII
HIS KINDNESS TO OTHERS
Birds are helpful to each other when in trouble. If a robin is in distress, other robins will come to see what is the matter, and to help if they can. And not only robins, but catbirds, and orioles, and chickadees, and others, will come, too.