The Prince George's enquirer and southern Maryland advertiser. (Upper Marlborough, Md.) 1882-1925, 1897-02-26
THE COLORS OF BIRDS.

A remarkable law of nature has on
ly recently been discovered and FORM
ulated by the artist, Mr.. Abbott II.
Thayer. For more than a generation
of men, naturalists have been studying
the part which color plays in protect
ing animals from their enemies. Pro
tective coloration is the technical name
which is given to such cases of protec-
ton, and much keenness of observa-
ton and Of reasoning has been shown
by students of the great problems of
evolution. Yet no naturalist has ever
perceived the secret of protective col
Grafton, which, as the name suggests,
lies in the painters province, and
might never have been discovered by
naturaists.
''The law of gradation in the color
ing Of animals" says Mr.. Thayer, ais
responsible for most of the phenomena
OF protective coloration except those
properly called 'mimicry.' Mimicry
makes an animal appear to be some
other thing, whereas this newly-dis-
covered law makes him cease TO appear
to exist all. For example, the screech-
owl, when startled, makes himself tall
and slim, and, with eyes shut to mar
row line, Stimulates dead stub of the
tree OH which he sits. Certain herons
stretch their necks straight upward,
and, with head and green back pointed
at the zenith, pass themselves off for
blades of sedge-grass. Many butter
fles have stone or bark colored under
sides to their wings, which make them
look like bit of bark or lichen when
they sit still on stone or tree-trunk,
with wings shut over their backs.
The newly-discovered law may be
stated thus: Animals are painted by
nature darkest on those parts which
tend to be most lighted by the sky's
light and rice vers0."
The ruffed grouse is bird which
shows the gradation in its simplest
form, the color making a complete
gradation from brown above to silvery
white beneath. The top light makes
him so like his surroundings that he
is nearly, if not quite, obliterated. The
cause of this oblteration has been as
signed to the fact that his color is like
that ofhis surroundings. Mr.. Thayer
ingeniously proves not only that, were
he colored like his surroundings, he
would be completely visible, but
proves at the same time what the true
cause of his concealment is. He care
fully and accurately painted dead
grouse Oh the lower part of the body,
with brown to match his back, and
painted the sides in gradation till the
bird was uniformly colored all over,
except that the upper surfaces were
left as nature painted them. He then
set the bird up in lifelike position on
the ground. The effect was magical.
What was before almost invisible at
short distance became clearly visible,
proving that is is only this graduation
of color which deserves the name of
protective coloration, and that it is the
compound graduation made by the day
lights cooperation which conceals the
animal.
Mr.. Thayer made some wooden eggs
of about the size of woodcock's body,
and mounted them on wire legs about
six inches above the ground. Most of
them were colored in imitation of the
color-gradation of a grouse or hare,
being earth-color above to pure white
beneath. To two of the wooden eggs
he gave coat of earth color all over
and then set the whole, like a flock of
shore-birds, on the bare ground in a
city lot. He then invited naturalist
to look for them, beginning at a dis
tance of forty or fifty yards. The nat
uralist saw Immediately the two mon
orchrome ones; but, although he was
told exactly where to look, he failed
to find any of the others till he was
within six or seven yards of them, and
even then he saw them only by know
ing exactly where to look.
The reader can easily get an illus
tration Of this law with no more trouble
than merely using his eyes. Look at
horizontal branch of tree in the
woods, which is either on the level OF
the eye or below it. You will ace
that, although it has exactly the color
of it's surroundings, it is not at all
concealed. This is because it is of uni
form color above and below it. You
will see that, although it has exactly
the color of its surroundings, it is not
at all concealed. This is because it is
of uniform color above and below, and
wears that uniform attitude of solid
Ia gradation of shade from its light