Evening star., 1936-09-17
THIS AND THAT <
BY CHARLES E. TRACEWELL.

A correspondent asks about the pro-
tective coloration OF animals, at the
same time voicing some doubt about the
theory.
Since their enemies mostly depend on
the sense Of smell, anyway, he says,
what is the use Of the stripes and other
patterns, which are supposed to protect
them?
1t may be that the camoufiage or the
carnivorous species, such as tigers and
leopards. is rather to keep their prey
from seeing them.
Protective coloration, in such cases,
seems to be for the sole purpose of con-
cealing the creature from possible food,
which "food," it is obvious, is Of the
walking and running kind.
This is seen very we'll in the case Of
the small aquarium inmate popularity
known as angel fish. This fish is as
thin as wafer, bright silver hae.
marked with intense black stripes run
ming up and down.
No doubt these blend nicely when
the fish is in its natural habit, among
the long blades Of eel grass. or similar
grasses. If an unwary smaller fish
comes along, and the angel fish remains
quite still until it is within swapping
distance, the prey will go down the
angels gullet head first before it knows
what has happened.
How about the other way around? If
a really large fish swims by, would his
stripes protect the angel?
y
There can be little doubt that, as
long as he remained in the grasses, they
tn hn1r n 1iyyr ia xy
eyes of his larger foe.
Once he came out into the open
waters, he would be all the more con-
spicuous because of his bold markings.
We may believe, then, that protective
markings only hold good, and function.
in certain locations, and are useless, or
even worse than useless, elsewhere.
Certainly zebra running across the
plain would attract the attention of any
thing with eyes.
Hence it may be felt that all such
protective devices are for moments and
places only; that they are by no means
inclusive. and that they may be, in
total service, rather a mistake than
otherwise.
The animal colors and patterns have
been the same since man has known
anything about them. But what were
the conditions under which they lived
before history knew them? That they
were different there can be no doubt.
The habitat probably was such as made
their colors and stripes a great deal
more to the point, whatever that point
was, and no one can be sure exactly
what it was this far away.
-
1t may be believed. too, that only such
coloration is protective as really pro-
tects.
For instance, there is nothing protec-
tive about the red of the cardinal, or
redbird.
In the early days of the Republic its
bright feathers made it an easy mark
for the long rifles of the pioneers.
If one had no interest in birds. as
such. it was natural that a rif1eman
should shoot at such a shining mark.
The result was that thousands of
these beautiful birds met a totally un-
necessary death. largely due to their
brilliant plumage.
flying in jungles wreathed with gorgeous
orchids, find their amazing plumage a
real protection.
In American forests, however, any
thing with real color to it is picked out
instantly by that very fact.
Yet birds in general. as this country
knows its songsters. often have cleverly
camouflaged wings and breasts. These
take the form of brown and gray
feathers, sometimes marked with spots,