This is because the first feathers of the wings and tail are longer than the ones that grow in their place when the young eagle has once shed them. The young eagle is also darker than the old one. This is why some people have made mistakes in writing about them without knowing a young eagle from an old one. Eagles of the same kind are not always of the same color. Some are darker than others and the markings are not alike.
Some young eagles shed their downy feathers early and wear the dress of grown-up birds.
Others keep some or all of their baby feathers five or six years. And there are some very old eagles still wearing some of the downy feathers of their first dresses. Eagles kept in cages lose some of their fierce ways and change the colors of their dress. But they do not forget that they are eagles. A large cat once went under the bars of an eagle's cage to get the meat which had not been eaten by the bird.