754 
FOREST AND STREAM 
Dec. 13, 1913. 
Protective Coloring and Mimicry in Animal Life 
By W. G. BEECROFT 
I T is a well known fact that, in nature, every 
animal has what is called a natural enemy, 
or several of them, to guard against; and 
for the preservation of life, it is necessary to 
use every available means and artifice, in order, 
if possible, to frustrate the plans, and defeat the 
purposes of these enemies, whether the method 
be by force, cunning, or otherwise; and as the 
natural conditions are those of a state of war, 
it follows that it is both necessary and desirable 
to take every advantage of the enemy, on all 
possible occasions, since the battle is to the strong 
.and the most resourceful. 
The hen-pheasant, actuated by what is called 
instinct, or what is perhaps more correctly de¬ 
signated a rudimentary form of reason, selects 
for her nest a hollow on the verge of a thicket 
•where the partly exposed reddish clay, sur¬ 
rounded with withered leaves and twigs, harmon¬ 
izes with the color of her plumage; so much 
so that, to a casual observer, she becomes prac¬ 
tically unrecognizable; and is thus able to hatch 
her young in peace and safety. The dull plum¬ 
age, so different from the brighter appearance 
of the male bird, acting as a valuable protection. 
Many birds build their nests in places where 
the surroundings closely resemble the color of 
their eggs, notably in the case of the tern, which 
lays among the rounded and polished stones on 
the seashore. The wild duck hatches her young, 
while sitting on a nest formed of dried grass 
and bull rushes, in a lake or marsh. A snipe, as 
she sits on her nest, is exactly the color of the 
withered grass with which she is surrounded. The 
plumage of the grouse is indistinguishable from 
the heather in which she builds her nest. 
A hare makes its “form,” or lair, among 
the clods of a ploughed field, selecting clay as 
near the color of its own fur as possible. A 
tuft of withered grass or weeds usually over¬ 
hangs the lair. So confident is the hare of its 
safety in this “protected” retreat, that it frequent¬ 
ly happens that it will not move until forced to 
do so by its enemies. 
While animals such as the arctic fox, polar 
bear, and the ptarmigan in its Winter plumage, 
are scarcely observable upon the snow, the latter 
and the mountain-hare are subject to variable 
coloring at different seasons. It is known that, 
in some cases, the pigmented hairs and plumage 
become white; in other cases the old feathers and 
hairs fall off, and are replaced by white ones; 
occasionally the whiteness is the result of both 
these processes. 
Prof. Thomson, of Edinburgh University, 
states that, in his opinion, the whiteness is due 
to the formation of gas-bubbles inside the hairs 
or feathers, in sufficient quantity to antagonize 
the effect of any pigment that may be present, 
but in the new growths it is not likely that any 
pigment is formed. In some cases, notably the 
American hare (Lepus Americanus) and Ross’s 
lemming, it has been ascertained that the change 
is directly due to the cold. Most likely this acts 
upon the skin through the nervous system. The 
■change is probably a variation due to environ¬ 
ment; and no doubt, in cases of permanent white¬ 
ness such as the polar bear, the acquired charac¬ 
ter is of like origin. 
The protective coloring in the flat fish, such 
as turbot, plaice, sole, flounder, etc., is very re¬ 
markable. These fish live close to the sandy 
bottom of the sea, and they all develop, on their 
upper side sometimes erroneously called the 
(“back”), a sandy grey color. In the turbot, the 
upper side has the most perfect resemblance to 
sea sand; even little grains, as of gravel, are 
scattered all over the colored skin. 
It is remarkable that, in clear and bright 
waters, most fish are usually silvered so as to cor¬ 
respond with the water. Many transparent and 
translucent blue animals, inhabiting the sea, are 
scarcely recognizable. 
The antlers of the deer would appear to be 
very awkward and useless appendages; but a 
deer, lying down among brushwood and ferns, 
may escape the attention of a tiger or leopard, 
because of its resemblance to the bare branches 
of a withered tree. Many insects escape the no¬ 
tice of their enemies by simulating leaves of trees, 
bare twigs, mosses, etc. All these adaptations are 
not due to any conscious change in the consti¬ 
tution of the subjects. It is merely a case of the 
fact that variation in individuals is a constant 
law of nature. Of these variations, some will 
be certain to prove more adaptable to -their sur¬ 
roundings than others; and these are the ones 
which are the most certain to come out success¬ 
ful in the struggle for existence. The natural 
operation of this principle is the agency through 
which all morphological changes in both animals 
and plants, are brought about. Feigning death is 
a device adopted at times by some animals, both 
for purposes of defence and attack. Some kinds 
of hairy caterpillars, if touched while moving 
along the ground, will roll over, apparently dead ; 
but if left alone for a few minutes they start 
up again and proceed on their journey in quite a 
lively fashion just as if nothing had occurred. 
It is an old trick of a fox to feign death 
while lying in the path of a flock of geese until 
they come within striking distance, when he 
pounces upon them in vigorous style. Certain 
flies are able to mimic a honey-bee so completely 
that they are often able to pass into the bee’s 
nest without being detected by the sentry. Many 
beetles, too, accurately mimic bees, wasps, and 
ants. The common drone fly (Eristalis) is like 
a bee; and some spiders resemble ants, while the 
survival of the fittest—a principle based on th** 
humming-bird moth (Macroglossa titan) has si- 
closely mimicked a certain kind of humming-birit 
(Lophornis gouldii) that Mr. Bates mentions tha: 
he often shot the moth in mistake for the hum¬ 
ming-bird. The protective effect of resemblance 
to surroundings is exemplified in the concealment 
of green animals such as tree-frogs, snakes, liz¬ 
ards, and many insects, by hiding among the 
green leaves and herbs. 
Spotted animals such as snakes, leopards, 
giraffes, etc., liye unobserved in the forests where 
the rays of light are interrupted by branches, 
twigs and leaves. 
Remarkable and interesting are the cases of 
quick color changes which have been noticed in 
some amphibians such as tree-frogs, and in sev¬ 
eral fishes, such as plaice, minnows, trout, and 
stickleback; and in many crustaceans. 
The investigations of Brucke, Ponchet and 
others, have shown that the color of surroundings 
influences animals through the medium of the 
eyes; in proof of which blind plaice, frogs, or 
trout are immune from change of tint. The 
nervous excitation passes from the eye to the I 
brain, and thence extends not down the spinal 
cord, but down the sympathetic chain. Should 
this be cut the change in color does not take 
place. The sympathetic system is connected with 
nerves which pass from the spinal cord to the 
skin; and it is along these nerves that the im¬ 
pulse is further conveyed, the result of which 
action is the contraction or expansion of the 
pigment contained in the cells of the skin. The 
changes here involved are frequently very rapid. 
As the consequent resemblance to surroundings 
is often very marked, there can be little doubt 
that the possessor of the peculiarity derives con¬ 
siderable advantage therefrom. 
The resemblance between animals and their 
surroundings is often very striking, not only in 
color but in form. Some bright butterflies such 
as the Kallina, are conspicuous when in flight, 
but when they alight upon a branch of a tree or 
shrub, and expose the under sides of their raised 
wings they become exactly like brown withered 
leaves. 
Among caterpillars, protective resemblance is 
very common; a fact which is attributed by Mr. 
Poulton to the defenceless condition of these 
young animals. They are generally colored so 
as to avoid detection, or in order to warn off some 
unpleasant attribute: the object in each case be¬ 
ing similar—to leave the caterpillar larvae un¬ 
touched; as a mere touch is often fatal in its 
consequences. 
While many animals are protected by their 
pigmentation, others are, on the contrary, made 
conspicuous. But these latter are usually un¬ 
palatable or dangerous. A. R. Wallace, the well 
known associate of Darwin, was of opinion that 
the conspicuous colors, in these cases, are warn¬ 
ings to the enemies, and as Mr. Poulton sug¬ 
gests, “to enable them easily to learn and re- 
