not bright clear blue as it is in spring?"

"I think not," answered Nat.

"Well, the outside edges of its feathers are blue, but a little deeper
in the feather is brownish. So when they have worn the same feathers
many months, and rubbed in and out of their little houses and bathed a
great deal and cleaned their feathers off every day in the dust, as
birds always do, the blue ends wear off and the rusty parts show. It is
quite worth while to tell little people things when they have the
patience to listen and the interest to remember."

"Yes, uncle, but it's the way you tell us about birds that makes us
remember. You talk as if they were real people."

"Oh, oh, Nat!" laughed the Doctor, "if you flatter me so I shall have to
hide my head in a bush like an Ostrich. Birds _are_ people, though of
another race from ours, and I am happy if I can make you think so. Ah!
we must be near a Redwing's nest--what a commotion the colony is
making!"

"Colony? I thought a colony was a lot of people who went off into a
strange wild land and made a new home," said Nat.

"That is one meaning of the word, but another one is when a number of
people of the same race or trade live close to each other. A bird colony
is a collection of the homes of many birds of the same family. After the
nesting season almost all birds live in flocks of different sizes, each
particular kind flocking by itself; but during the migrations great
flocks are often made up of smaller flocks of various kinds of birds.