The Winslow mail., 1897-12-18
AN ARTISTS DISCOVERY.
How Nature Has Wisely CoIored the
Birds.

How Nature Has Wisely CoIored the
Birds.
An exceedingly interesting natural
law has been discovered by the distin-
gulshed artist, Mr.. Abbott H Thayer,
who is an ardent observer of bird life.
lie, with his artists eye for light and
shade, discovered what the naturalsts.
Notwithstanding their acquaintance
with many varieties of initiative and
protective coloration in animals, had
as yet failed to elucidate the reason
why the under parts of fishes, reptiles,
mammals, birds, and even insects are
SO generally white or light. 1t is a law
which can be very simply stated thus:
Animals are painted by nature dark
est on those parts which tend to be
most lighted by the sky's light, and vice
versa"
VI course, out-of-doors the light comes
commonly from above and thus the
majority of wild creatures are darker
on their backs and lighter below, where
the shadow of their own bodies upon
the lighter color tends to equaliZe it
with that of the upper parts. Thus,
oead bird with wood-colored back,
llghter shades on wing and sides and
white breast may look, when held in
tne hand, as if the conspicuous, silvery
Drllliance of the breast feathers would
easily betray it to the eye of search
ing enemy. Not at all. 1t would be
much more easily discovered if it were
/ VI; NJ, I'M.
proved at an open-air meeting of orni-
thologlsts in Cambridge last November
ny series of cleveriy devised expert
ments.
lie placed three objects of about the
size and shape of sweet potatoes-in
TACT, they were sweet potatoes-horl-
zohtaIiy on wires few inches above
the ground. They were covered with
sucky material, and then dry earth
from the road where they stood was
sprlnkled over them to give them the
very color of their background. DR.. G.
Hart Merriam, in report of this talk
to Science, says:
Ihe two end ones were painted
white on the under side, and the white
color was shaded up and gradually mix
ed with the brown of the sides.
Wnen viewed from a little distance.
these two end ones, which were white
Delow, disappeared from sight, while
the middle one stood out in strong re-
lief, and appeared much darker than II
really was. Mr.. Thayer explained that
terrestrial birds and mammals, which
are protectively colored, have the under
parts white, or very light in color, and
that the color of the under parts usual
~ shades gradually into that of the
upper parts.
This is essential in order to counter
act the effect of the shadow side, which
otherWlse, as shown by the middle
potato, makes the object abnormally
conspicuous, and causes it to appear
much darker than it really is.
I'm the case of Mr.. Thayer's expert
ment, some of the witnesses could hard
ly believe that the striking difference
IN the visibility of the three potatoes
was entirely due to the coloring of the
under side, and Mr.. Thayer was asked
| ~ SOAOA lHC LuIuuic Ouc ike the TWO
others, in order that the effect might be
observed. Mr.. Thayer complied with
the request, painting the under side of
the middle potato white, and shading
the white up into the sides, as in the
case of the others.
'The effect was almost magical. The
middle potato at once disappeared from
view.
"a similar experiment was made on
the lawn. Two potatoes were painted
green, to resemble the green of the
grass above which they were suspend
ed. One was painted white on the un-
der side, and at once became invisible
when viewed from a little distance,
while the other showed plainly and
seemed very dark, the shadow, super
added to the green of the under side,
making it remarkably conspicuous.
The experiments were an overwhelm-
ing success"
The rule of natural coloring which
Mr. Thayer thus .erceved like an art
ist and proved Ike a scientist Is so
general throughout the animal king
dom, and of such Importance in pre-
serving species from destruction, that
many naturalists declare him to have
made, not merely remarkable discov-
cry, but great discovery.