VII
HOW HE CHANGES HIS CLOTHES
It takes a bird weeks to put on a new suit of clothes. He has nothing but his feathers to protect him from cold and wet, and as feathers cannot grow out in a minute, he would be left naked, and suffer, if he lost them all at once. So he changes his dress one or two feathers at a time.
Some day a feather will drop from each wing. If you could look, you would see that new ones had started out in the same place, and pushed the old ones off. When the new ones are pretty well grown another pair will fall out.
If all dropped out at once, besides suffering with cold he would not be able to fly, and he could not get his living, and anybody could catch him. But losing only one from each side at a time, he always has enough to fly with.
It is the same way with his tail feathers. He loses them in pairs, one from each side at the same time.
AMERICAN GOLDFINCH