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.
During the nesting season it is quite different; the majority of birds
prefer a quiet home life, each pair being independent of any others.
Certain flocks, however, keep together, and all build their nests in a
particular swamp or wood, and sometimes, it is said, male birds build
nests to sleep in while the females are sitting. The Redwings nest in
colonies; so do the Herons, who eat frogs and nest near water, and the
little brown-cloaked Bank Swallows, who live in holes that they dig for
themselves in high banks."

There were some twenty pairs of birds in this Redwing colony, who seemed
to be much frightened by the approach of visitors.

"Here is a nest in this alder bush," said the Doctor; "step carefully on
the grass hummocks, and look at it for a moment, Nat. See how neatly it
is made of the dried leaves of flags and grasses, woven in and out
between three upright stalks."

"Isn't it pretty?" said Nat; "so even and deep like a cup, and not at
all ragged and mussy like a Robin's nest. There are a great many
different kinds of nests, aren't there, uncle?"

"Yes, the nests of birds are almost as different as their songs and
other habits, and the higher the order the brood belongs to the better
built is the nest. The lower orders often only make a hollow in the
ground or grass, but do not collect material and _build_ in the true
sense. None such can be called architects."

"What is an architect?" asked Nat, who thought it was a pretty big name
for any sort of a bird. "An architect, my boy," said the Doctor, "is
anybody who knows how to build anything as it ought to be built, to look
the best and be the most useful, whether it is a house or a nest."

"I wonder why nests are so different," said Rap, looking down the lane
toward the river where the sun was streaming in and so many little birds
were flying to and fro that they seemed like last year's leaves being
blown about.

"Because, as the habits of the birds cause them to live in different
places, and feed in various ways, so their homes must be suitable to
their surroundings, and be built in the best way to protect the young
birds from harm--to keep them safe from Hous