More than this, we see that they do not look nor act exactly like each other. For when we know one robin or one oriole well, we can tell him from any other robin or oriole. And, as I said before, no two of a kind sing precisely the same song.
A bird shows his intelligence in many ways. One is by the way he acts when he cannot do as he is used to doing. A robin I know of wished to build a nest, but could not find mud to put into it, for it was a very dry time, and there were no streams near. Now a robin's nest must have mud, and the bird seemed puzzled for a while. But at last she thought of a way to get it.
She went to a bathing-dish that the people of the house kept filled with water for the birds, jumped into it, and got her legs very wet. Then she flew to the road, and tramped around in the dust and dirt.
In a short time her legs had a good coating of mud, which she carefully picked off with her bill, and took to the nest she was building.
This she did a great many times, and the lady who told me of it watched her till she had as much mud as she needed.
A bird often shows sense by the way she repairs a nest that has been thrown out of place. Sometimes she will add a new stay, tying the nest to a stronger limb. One sparrow, whose nest broke loose, put so many stays to the branch above that they made a little roof like a tent over it.
Another way a bird shows reason is in seeing the advantage of a new place. A pair of swallows lived far out in the West, hundreds of miles from any house. They had no doubt always nested in a cave, or a hole in a tree. But one day they found a house put up. It was a mere shed, to be used as a blacksmith shop, by a party of men who were looking over the country.
At once the birds saw how nice it would be to have a roof over their heads. And although there was a big fire, and the noise of men at work, they built the nest over the anvil, and reared the family in safety.
Woodpeckers have shown that they can learn. Some of them have found an easier way to get food than to dig through the bark of trees for it.
The flicker, or golden-winged woodpecker, has learned that ants and other insects are good to eat, and now he does not think of digging into bark any more.