and it has not the form, or the color, or the eye of a bird of prey,
and thus probably deceives its victims, but there is no reason to
believe that this guise is the result of any sort of mimicry.
V. THE COLORS OF FRUITS
Mr. Wallace even looks upon the nuts as protectively colored, because
they are not to be eaten. But without the agency of the birds and the
squirrels, how are the heavy nuts, such as the chestnut, beechnut,
acorn, butternut, and the like, to be scattered? The blue jay is often
busy hours at a time in the fall, planting chestnuts and acorns, and
red squirrels carry butternuts and walnuts far from the parent trees,
and place them in forked limbs and holes for future use. Of course,
many of these fall to the ground and take root. If the protective
coloration of the nuts, then, were effective, it would defeat a
purpose which every tree and shrub and plant has at heart, namely, the
scattering of its seed. I notice that the button-balls on the
sycamores are protectively colored also, and certainly they do not
crave concealment. It is true that they hang on the naked trees till
spring, when no concealment is possible. It is also true that the jays
and the crows carry away the chestnuts from the open burrs on the
trees where no color scheme would conceal them. But the squirrels find
them upon the ground even beneath the snow, being guided, no doubt, by
the sense of smell.
The hickory nut is almost white; why does it not seek concealment
also? It is just as helpless as the others, and is just as
sweet-meated. It occurs to me that birds can do nothing with it on
account of its thick shell; it needs, therefore, to attract some
four-footed creature that will carry it away from the parent tree, and
this is done by the mice and the squirrels. But if this is the reason
of its whiteness, there is the dusky butternut and the black walnut,
both more or less concealed by their color, and yet having the same
need of some creature to scatter them.
The seeds of the maple, and of the ash and the linden, are obscurely
colored, and they are winged; hence they do not need the aid of any
creature in their dissemination. To say that this is the reason of
their dull, unattractive tints would be an explanation on a par with
much that one hears about the significance of animal and vegetable
coloration. Why is corn so bright colored, and wheat and barley so
dull, and rice so white? No doubt there is a reason in each case, but
I doubt if that reason has any relation to the surrounding animal
life.
The new Botany teaches that the flowers have color and perfume to
attract the insects to aid in their fertilization--a need so paramount
with all plants, because plants that are fertilized by aid of the wind
have very inconspicuous flowers. Is it equally true that the high
color of most fruits is to attract some hungry creature to come and
eat them and thus scatter the seeds? From the dwarf cornel, or
bunch-berry, in the woods, to the red thorn in the fields, every
fruit-bearing plant and shrub and tree seems to advertise itself to
the passer-by in its bright hues. Apparently there is no other use to
the plant of the fleshy pericarp than to serve as a bait or wage for
some animal to come and sow its seed. Why, then, should it not take on
these alluring colors to help along this end? And yet there comes the
thought, may not this scarlet and gold of the berries and tree fruits
be the inevitable result of the chemistry of ripening, as it is with
the autumn foliage? What benefit to the tree, directly or indirectly,
is all this wealth of color of the autumn? Many of the toadstools are
highly colored also; how do they profit by it? Many of the shells upon
the beach are very showy; to what end? The cherry-birds find the pale
ox-hearts as readily as they do the brilliant Murillos, and the dull
blue cedar berries and the duller drupes of the lotus are not
concealed from them nor from the robins. But it is true that the
greenish white grapes in the vineyard do not suffer from the attacks
of the birds as do the blue and red ones. The reason probably is that
the birds regard them as unripe. The white grape is quite recent, and
the birds have not yet "caught on."
Poisonous fruits are also highly colored; to what end? In Bermuda I
saw on low bushes great masses of what they called "pigeon-berries" of
a brilliant yellow color and very tempting, yet I was assured they
were poisonous. It would be interesting to know if anything eats the
red berries of our wild turnip or arum. I doubt if any bird or beast
could stand them. Wherefore, then, are they so brightly colored? I am
also equally curious to know if anything eats the fruit of the red and
white baneberry and the blue cohosh.
The seeds of some wild fruit, such as the climbing bitter-sweet, are
so soft that it seems impossible they should pass through the gizzard
of a bird and not be destroyed.
The fruit of the sumac comes the nearest to being a cheat of anything
I know of in nature--a collection of seeds covered with a flannel coat
with just a perceptible acid taste, and all highly colored. Unless the
seed itself is digested, what is there to tempt the bird to devour it,
or to reward it for so doing?
In the tropics one sees fruits that do not become bright colored on
ripening, such as the breadfruit, the custard apple, the naseberry,
the mango. And tropical foliage never colors up as does the foliage of
northern trees.
VI. INSTINCT
Many false notions seem to be current in the popular mind about
instinct. Apparently, some of our writers on natural history themes
would like to discard the word entirely. Now instinct is not opposed
to intelligence; it is intelligence of the unlearned, unconscious
kind,--the intelligence innate in nature. We use the word to
distinguish a gift or faculty which animals possess, and which is
independent of instruction and experience, from the mental equipment
of man which depends mainly upon instruction and experience. A man has
to be taught to do that which the lower animals do from nature. Hence
the animals do not progress in knowledge, while man's progress is
almost limitless. A man is an animal born again into a higher
spiritual plane. He has lost or shed many of his animal instincts in
the process, but he has gained the capacity for great and wonderful
improvement.
Instinct is opposed to reason, to reflection, to thought,--to that
kind of intelligence which knows and takes cognizance of itself.
Instinct is that lower form of intelligence which acts through the
senses,--sense perception, sense association, sense memory,--which we
share with the animals, though their eyes and ears and noses are often
quicker and keener than ours. Hence the animals know only the present,
visible, objective world, while man through his gift of reason and
thought knows the inward world of ideas and ideal relations.
An animal for the most part knows all that it is necessary for it to
know as soon as it reaches maturity; what it learns beyond that, what
it learns at the hands of the animal-trainer, for instance, it learns
slowly, through a long repetition of the process of trial and
failure. Man also achieves many things through practice alone, or
through the same process of trial and failure. Much of his manual
skill comes in this way, but he learns certain things through the
exercise of his reason; he sees how the thing is done, and the
relation of the elements of the problem to one another. The trained
animal never sees _how_ the thing is done, it simply does it
automatically, because certain sense impressions have been stamped
upon it till a habit has been formed, just as a man will often wind
his watch before going to bed, or do some other accustomed act,
without thinking of it.
The bird builds her nest and builds it intelligently, that is, she
adapts means to an end; but there is no reason to suppose that she
_thinks_ about it in the sense that man does when he builds his house.
The nest-building instinct is stimulated into activity by outward
conditions of place and climate and food supply as truly as the growth
of a plant is thus stimulated.
As I look upon the matter, the most wonderful and ingenious nests in
the world, as those of the weaver-birds and orioles, show no more
independent self-directed and self-originated thought than does the
rude nest of the pigeon or the cuckoo. They evince a higher grade of
intelligent instinct, and that is all. Both are equally the result of
natural promptings, and not of acquired skill, or the lack of it. One
species of bird will occasionally learn the song of another species,
but the song impulse must be there to begin with, and this must be
stimulated in the right way at the right time. A caged English sparrow
has been known to learn the song of the canary caged with or near it,
but the sparrow certainly inherits the song impulse. One has proof of
this when he hears a company of these sparrows sitting in a tree in
spring chattering and chirping in unison, and almost reaching an
utterance that is song-like. Our cedar-bird does not seem to have the
song impulse, and I doubt if it could ever be taught to sing. In like
manner our ruffed grouse has but feeble vocal powers, and I do not
suppose it would learn to crow or cackle if brought up in the
barn-yard. It expresses its joy at the return of spring and the mating
season in its drum, as do the woodpeckers.
The recent English writer Richard Kearton says there is "no such dead
level of unreasoning instinct" in the animal world as is popularly
supposed, and he seems to base the remark upon the fact that he found
certain of the cavities or holes in a hay-rick where sparrows roosted
lined with feathers, while others were not lined. Such departures from
a level line of habit as this are common enough among all creatures.
Instinct is not something as rigid as cast iron; it does not
invariably act like a machine, always the same. The animal is
something alive, and is subject to the law of variation. Instinct may
act more strongly in one kind than in another, just as reason may act
more strongly in one man than in another, or as one animal may have
greater speed or courage than another of the same species. It would be
hard to find two live creatures, very far up in the scale, exactly
alike. A thrush may use much mud in the construction of its nest, or
it may use little or none at all; the oriole may weave strings into
its nest, or it may use only dry grasses and horse-hairs; such cases
only show variations in the action of instinct. But if an oriole
should build a nest like a robin, or a robin build like a cliff
swallow, that would be a departure from instinct to take note of.
Some birds show a much higher degree of variability than others; some
species vary much in song, others in nesting and in feeding habits. I
have never noticed much variation in the songs of robins, but in their
nesting-habits they vary constantly. Thus one nest will be almost
destitute of mud, while another will be composed almost mainly of mud;
one will have a large mass of dry grass and weeds as its foundation,
while the next one will have little or no foundation of the kind. The
sites chosen vary still more, ranging from the ground all the way to
the tops of trees. I have seen a robin's nest built in the centre of a
small box that held a clump of ferns, which stood by the roadside on
the top of a low post near a house, and without cover or shield of
any sort. The robin had welded her nest so completely to the soil in
the box that the whole could be lifted by the rim of the nest. She had
given a very pretty and unique effect to the nest by a border of fine
dark rootlets skillfully woven together. The song sparrow shows a high
degree of variability both in its song and in its nesting-habits, each
bird having several songs of its own, while one may nest upon the
ground and another in a low bush, or in the vines on the side of your
house. The vesper sparrow, on the other hand, shows a much lower
degree of variability, the individuals rarely differing in their
songs, while all the nests I have ever found of this sparrow were in
open grassy fields upon the ground. The chipping or social sparrow is
usually very constant in its song and its nesting-habits, and yet one
season a chippy built her nest in an old robin's nest in the vines on
my porch. It was a very pretty instance of adaptation on the part of
the little bird. Another chippy that I knew had an original song, one
that resembled the sound of a small tin whistle. The bush sparrow,
too, is pretty constant in choosing a bush in which to place its nest,
yet I once found the nest of this sparrow upon the ground in an open
field with suitable bushes within a few yards of it. The woodpeckers,
the jays, the cuckoos, the pewees, the warblers, and other wood birds
show only a low degree of variability in song, feeding, and nesting
habits. The Baltimore oriole makes free use of strings in its
nest-building, and the songs of different birds of this species vary
greatly, while the orchard oriole makes no use of strings, so far as I
have observed, and its song is always and everywhere the same. Hence
we may say that the lives of some birds run much more in ruts than do
those of others; they show less plasticity of instinct, and are
perhaps for that reason less near the state of free intelligence.
Organic life in all its forms is flexible; instinct is flexible; the
habits of all the animals change more or less with changed conditions,
but the range of the fluctuations in the lives of the wild creatures
is very limited, and is always determined by surrounding
circumstances, and not by individual volition, as it so often is in
the case of man. In a treeless country birds that sing on the perch
elsewhere will sing on the wing. The black bear in the Southern States
"holes up" for a much shorter period than in Canada or the Rockies.
Why is the spruce grouse so stupid compared with most other species?
Why is the Canada jay so tame and familiar about your camp in the
northern woods or in the Rockies, and the other jays so wary? Such
variations, of course, have their natural explanation, whatever it may
be. In New Zealand there is a parrot, the kea, that once lived upon
honey and fruit, but that now lives upon the sheep, tearing its way
down to the kidney fat.
This is a wide departure in instinct, but it is not to be read as a
development of reason in its place. It is a modified instinct,--the
instinct for food seeking new sources of supply. Exactly how it came
about would be interesting to know. Our oriole is an insectivorous
bird, but in some localities it is very destructive in the August
vineyards. It does not become a fruit-eater like the robin, but a
juice-sucker; it punctures the grapes for their unfermented wine.
Here, again, we have a case of modified and adaptive instinct. All
animals are more or less adaptive, and avail themselves of new sources
of food supply. When the southern savannas were planted with rice, the
bobolinks soon found that this food suited them. A few years ago we
had a great visitation in the Hudson River Valley of crossbills from
the north. They lingered till the fruit of the peach orchards had set,
when they discovered that here was a new source of food supply, and
they became very destructive to the promised crop by deftly cutting
out the embryo peaches. All such cases show how plastic and adaptive
instinct is, at least in relation to food supplies. Let me again say
that instinct is native, untaught intelligence, directed outward, but
never inward as in man.
VII. THE ROBIN
Probably, with us, no other bird is so closely associated with country
life as the robin; most of the time pleasantly, but for a brief
season, during cherry time, unpleasantly. His life touches or mingles
with ours at many points--in the dooryard, in the garden, in the
orchard, along the road, in the groves, in the woods. He is everywhere
except in the depths of the primitive forests, and he is always very
much at home. He does not hang timidly upon the skirts of our rural
life, like, say, the thrasher or the chewink; he plunges in boldly and
takes his chances, and his share, and often more than his share, of
whatever is going. What vigor, what cheer, how persistent, how
prolific, how adaptive; pugnacious, but cheery, pilfering, but
companionable!
When one first sees his ruddy breast upon the lawn in spring, or his
pert form outlined against a patch of lingering snow in the brown
fields, or hears his simple carol from the top of a leafless tree at
sundown, what a vernal thrill it gives one! What a train of pleasant
associations is quickened into life!
What pictures he makes upon the lawn! What attitudes he strikes! See
him seize a worm and yank it from its burrow!
I recently observed a robin boring for grubs in a country dooryard. It
is a common enough sight to witness one seize an angle-worm and drag
it from its burrow in the turf, but I am not sure that I ever before
saw one drill for grubs and bring the big white morsel to the surface.
The robin I am speaking of had a nest of young in a maple near by,
and she worked the neighborhood very industriously for food. She would
run along over the short grass after the manner of robins, stopping
every few feet, her form stiff and erect. Now and then she would
suddenly bend her head toward the ground and bring eye or ear for a
moment to bear intently upon it. Then she would spring to boring the
turf vigorously with her bill, changing her attitude at each stroke,
alert and watchful, throwing up the grass roots and little jets of
soil, stabbing deeper and deeper, growing every moment more and more
excited, till finally a fat grub was seized and brought forth. Time
after time, during several days, I saw her mine for grubs in this way
and drag them forth. How did she know where to drill? The insect was
in every case an inch below the surface. Did she hear it gnawing the
roots of the grasses, or did she see a movement in the turf beneath
which the grub was at work? I know not. I only know that she struck
her game unerringly each time. Only twice did I see her make a few
thrusts and then desist, as if she had been for the moment deceived.
How pugnacious the robin is! With what spunk and spirit he defends
himself against his enemies! Every spring I see the robins mobbing the
blue jays that go sneaking through the trees looking for eggs. The
crow blackbirds nest in my evergreens, and there is perpetual war
between them and the robins. The blackbirds devour the robins' eggs,
and the robins never cease to utter their protest, often backing it up
with blows. I saw two robins attack a young blackbird in the air, and
they tweaked out his feathers at a lively rate.
One spring a pack of robins killed a cuckoo near me that they found
robbing a nest. I did not witness the killing, but I have
cross-questioned a number of people who did see it, and I am convinced
of the fact. They set upon him when he was on the robin's nest, and
left him so bruised and helpless beneath it that he soon died. It was
the first intimation I had ever had that the cuckoo devoured the eggs
of other birds.
Two other well-authenticated cases have come to my knowledge of robins
killing cuckoos (the black-billed) in May. The robin knows its
enemies, and it is quite certain, I think, that the cuckoo is one of
them.
What a hustler the robin is! No wonder he gets on in the world. He is
early, he is handy, he is adaptive, he is tenacious. Before the leaves
are out in April the female begins her nest, concealing it as much as
she can in a tree-crotch, or placing it under a shed or porch, or even
under an overhanging bank upon the ground. One spring a robin built
her nest upon the ladder that was hung up beneath the eaves of the
wagon-shed. Having occasion to use the ladder, we placed the nest on a
box that stood beneath it. The robin was disturbed at first, but soon
went on with her incubating in the new and more exposed position. The
same spring one built her nest upon a beam in a half-finished fruit
house, going out and in through the unshingled roof. One day, just as
the eggs were hatched, we completed the roof, and kept up a hammering
about the place till near night; the mother robin scolded a good deal,
but she did not desert her young, and soon found her way in and out
the door.
If a robin makes up her mind to build upon your porch, and you make up
your mind that you do not want her there, there is likely to be
considerable trouble on both sides before the matter is settled. The
robin gets the start of you in the morning, and has her heap of dry
grass and straws in place before the jealous broom is stirring, and
she persists after you have cleaned out her rubbish half a dozen
times. Before you have discouraged her, you may have to shunt her off
of every plate or other "coign of vantage" with boards or shingles. A
strenuous bird indeed, and a hustler.
VIII. THE CROW
One very cold winter's morning, after a fall of nearly two feet of
snow, as I came out of my door three crows were perched in an apple
tree but a few rods away. One of them uttered a peculiar caw as they
saw me, but they did not fly away. It was not the usual high-keyed
note of alarm. It may have meant "Look out!" yet it seemed to me like
the asking of alms: "Here we are, three hungry neighbors of yours;
give us food." So I brought out the entrails and legs of a chicken,
and placed them upon the snow. The crows very soon discovered what I
had done, and with the usual suspicious movement of the closed wings
which has the effect of emphasizing the birds' alertness, approached
and devoured the food or carried it away. But there, was not the least
strife or dispute among them over the food. Indeed, each seemed ready
to give precedence to the others. In fact, the crow is a courtly,
fine-mannered bird. Birds of prey will rend one another over their
food; even buzzards will make some show of mauling one another with
their wings; but I have yet to see anything of the kind with that
gentle freebooter, the crow. Yet suspicion is his dominant trait.
Anything that looks like design puts him on his guard. The simplest
device in a cornfield usually suffices to keep him away. He suspects a
trap. His wit is not deep, but it is quick, and ever on the alert.
One of our natural history romancers makes the crows flock in June.
But the truth is, they do not flock till September. Through the summer
the different families keep pretty well together. You may see the old
ones with their young foraging about the fields, the young often being
fed by their parents.
From my boyhood I have seen the yearly meeting of the crows in
September or October, on a high grassy hill or a wooded ridge.
Apparently, all the crows from a large area assemble at these times;
you may see them coming, singly or in loose bands, from all directions
to the rendezvous, till there are hundreds of them together. They make
black an acre or two of ground. At intervals they all rise in the air,
and wheel about, all cawing at once. Then to the ground again, or to
the tree-tops, as the case may be; then, rising again, they send forth
the voice of the multitude. What does it all mean? I notice that this
rally is always preliminary to their going into winter quarters. It
would be interesting to know just the nature of the communication that
takes place between them. Not long afterwards, or early in October,
they may be seen morning and evening going to and from their
rookeries. The matter seems to be settled in these September
gatherings of the clan. Was the spot agreed upon beforehand and notice
served upon all the members of the tribe? Our "school-of-the-woods"
professors would probably infer something of the kind. I suspect it is
all brought about as naturally as any other aggregation of animals. A
few crows meet on the hill; they attract others and still others. The
rising of a body of them in the air, the circling and cawing, may be
an instinctive act to advertise the meeting to all the crows within
sight or hearing. At any rate, it has this effect, and they come
hurrying from all points.