*Reprinted by permission from "Forest and Stream."
So far as regards the recent discussion as to how animals learn,
whether by instinct or instruction, my study of birds leads me to take
a middle position; perhaps I would better say to take sides with both
parties. Birds acquire knowledge partly by instinct and partly by
tutelage, and the same is no doubt true of all other animals. This
statement will be borne out by several concrete cases.
Some years ago I made a number of experiments in rearing young birds
taken as early as possible from the nest. Among them were meadowlarks,
red-winged blackbirds, brown thrashers, blue jays, wood thrushes,
catbirds, flickers, red-headed woodpeckers, and several other species.
Nearly all of them were secured some time before they were naturally
ready to leave their natal places. Without any instruction from
parents or older birds they soon left the nests I had improvised for
them, hopped about on the cage floor for a while, and presently
insisted on clambering upon the perches, to which they clung in the
regulation way. Indeed, I noted again and again that the impulse to
seek a perch was so strong that the young birds seemed to be moved to
it by an imperative command. Nor were they long satisfied with a low
perch, but instinctively mounted to the highest one they could find.
The same was true in regard to flight. No feathered adult was present
to tutor them in the art of using their wings, yet they soon acquired
that power of their own accord. It was inborn--the gift of flight.
True, they were awkward at first, and gained skill only by degrees, but
the original impulse was in their constitution. It is no doubt true
that parent birds in the outdoors do give their young lessons in
flight, but if the bantlings were left to themselves, they would
acquire that art through their original endowment, although more slowly
and with many more hard knocks.
As every one knows, juvenile birds at first open their mouths for their
food. Proof may not be at hand for the opinion, but I am disposed to
believe that they never need to be told by their parents to do that;
their instincts prompt them. It must be so, I think, for to suppose
that the bird baby only a day or two from the shell could understand a
parental command to open its mouth would be to presume that it has the
instinct to grasp the meaning of such a behest, and that is more
difficult to believe than that Nature simply impels it to take its food
by opening its mandibles.
Now, when the young birds are taken from the nest and reared by hand,
they insist for a long time on being fed in the juvenile manner.
However, by and by they begin of their own volition to pick up food
after the manner of the adults. At first they are very clumsy about
it, but they persevere until they acquire skill, and presently they
refuse entirely to open their mandibles for food. Here again Nature is
their sole guide. Without human or avian suggestion they also learn to
drink in the well-known bird fashion; also to bathe, chirp, frolic, and
do many other things. Who has ever seen a pet bird in drinking try to
lap like a dog, or take in long draughts like a cow or a horse? No;
Nature made them birds, and birds they will be. It is noticeable, too,
that when birds begin to peck, or bathe, or seek a perch, they do not
usually act as if they were deliberately planning to do so, nor as if
they were carrying on some process of thought leading to choice, but
rather as if they were impelled by Nature to do so.
The chirping of birds is mostly, if not wholly, a matter of
inheritance. For instance, my little wood thrushes, as soon as they
reached a sufficient age, called just like their relatives of the
sylvan solitudes; my brown thrashers uttered the labial chirp of the
species; my red-winged blackbird exclaimed "Chack! chack!" after the
manner of his kind; my bluebirds expressed their feelings in the sad
little purr of _Sialia sialis_; my flickers did not borrow the calls of
the red-heads, but each clung to its own language; my catbirds mewed
like poor pussy in trouble; and so on through the whole list. True,
these pets may have heard their parents' calls before they were taken
from the nest, but it is not at all likely that they would have
remembered them, for at first they only "cheeped" after the manner of
most bantlings, and only a good while afterward did they fall to using
the adult chirp. Besides, while still in the nest, they must have
heard many other bird calls; why did they not acquire them? Heredity
has laid a strong hand upon birds, and has drawn sharp dividing lines
among the various species.
Instinct also plays a large part in moving the bird to sing and to
render the peculiar arias of its kind. For instance, a pet wood thrush
of mine, secured at an early age and kept far away from all his kith of
the wildwood, became a fine musician. And what do you suppose was the
tune he executed? It was the sweet, dreamy, somewhat labored song of
the wood thrush in his native wilds. He never sang any other tune. I
think he sang it better than any wild thrush I have ever heard. It was
louder, clearer, more full-toned, but the quality of voice and the
technique were precisely the same. Who was his teacher? No one but
Nature, heredity, instinct, whatever you choose to call it. There was
no wild thrush within a half mile of his cage.
[Illustration: Robin]
The case of a pet thrasher was almost as striking. It is true, he may
have heard several of his kin singing about the premises during the
first spring of his captivity, but it is not probable that he learned
their melodies so early in life. As the next spring approached, he
began to sing the very medleys that the wild thrashers sing with so
much earnestness and skill, and this was long before any thrashers had
come back from the South.
I must now describe several cases in which inherited instinct did not
prove so true a teacher. A young robin was once given me by a friend,
and was kept by myself and others until the following summer. Strange
as it may seem, he never acquired the well-known robin carol.
Sometimes there were vague hints of it in his vocal performances, but
for the most part he whistled strains in a loud, shrill tone that no
wild robin ever dreamed of inflicting on the world. They were more
like crude human efforts at whistling than anything else. Indeed, I
think they were picked up from the whistling he heard about the house.
Some of his strains were very sweet, and all of them were wonderful for
a bird. A friend played "Yankee Doodle" on a cornet, and Master
'Rastus--for that was his name--gave a very fair and funny imitation of
part of the air. There were many robins caroling in the trees about
the premises, and 'Rastus was often left out of doors among them, but
he never acquired the red-breast minstrelsy.
A similar instance was that of a pet red-winged blackbird, which,
instead of whistling the labored "Grook-o-lee" of his species, learned
to mimic all kinds of sounds in and out of the house, among them the
crowing of the cocks of the barnyard. These two instances would
indicate that some birds must at least be associated with their kin in
order to learn the songs of their species.
My comical pet blue jay gave proof of the need of parental training.
While he intuitively called like a jay, he never was able to sing the
sweet, gurgling roulade of the wild jays. On the contrary, he treated
us to all kinds of odd, imitative, mirth-provoking performances that no
self-respecting jay in the open would think of enacting. After several
months of cage life he was given his liberty. Now, indeed, he showed
his lack of jay bringing up, and how little, in some respects, mere
instinct can be relied on. When evening came he perched on a limb of
the maple tree before the house, in a place as exposed as he could well
find, not knowing that there was more danger in an outdoor roost than
in his shielding cage. I could not induce him to come down, nor could
I climb out to the branch on which he sat, and so I was compelled to
leave him out of doors.
The next morning he was safe, the screech owls of the neighborhood
having overlooked him in some way. The next evening he went to roost
in the same exposed place, and that was the last I ever saw of my
beloved pet. He was undoubtedly killed and devoured by the owls. Had
he been reared out of doors in the usual way, his parents would have
taught him to find a roosting place that was secure from predatory
foes. No one has ever seen a wild jay sleeping in an exposed place.
In her charming little book, "True Bird Stories," Mrs. Olive Thorne
Miller says that she "once watched the doings in a crow nursery." I
quote:
"The most important thing the elders had to do was to teach the
youngsters how to fly, and every little while one or both of the
parents would fly around the pasture, giving a peculiar call as they
went. This call appeared to be an order to the little folks to follow,
for all would start up and circle round for a minute or two, and then
drop back to the fence or the ground to rest.
"Once, while I was watching them, this cry was given, and all flew as
usual except one bob-tailed baby, who stood on a big stone in the
middle of the field. He was perhaps so comfortable that he did not
want to go, or it may be he was afraid, and thought mamma would not
notice him. But mothers' eyes are sharp, and she did see him. She
knew, too, that baby crows must learn to fly; so when all came down
again she flew right at the naughty bird, and knocked him off his
perch. He squawked, and fluttered his wings to keep from falling, but
the blow came so suddenly that he had not time to save himself, and he
fell flat on the ground. In a minute he clambered back upon his stone,
and I watched him closely. The next time the call came to fly he did
not linger, but went with the rest, and so long as I could watch him he
never disobeyed again."
This is evidence not only of parental teaching, but also of parental
discipline. Here is another bit from the same volume, bearing its
lesson on its face. "A lady told me a funny story about a robin. He
was brought up in the house from the nest, and never learned to sing
the robin song, for he had not heard it. He plainly tried to make some
sort of music, and one of the family taught him to whistle 'Yankee
Doodle'. He whistled it perfectly, and never tried to sing anything
else. Once this Yankee Doodle robin got out of the house and flew up
into a tree. When the wild birds came about him he entertained them by
whistling his favorite air, which sent the birds off in a panic."
Do not the facts recited in this sketch prove that birds know and
acquire some things through the promptings of instinct, while other
things they can learn only by avian teaching?
My notes on instinct and education in bird song correspond with the
conviction expressed by Dr. W. H. Hudson on page 257 of his interesting
book entitled "The Naturalist in La Plata," fourth edition, 1903: "It
is true that Daines Barrington's notion that young song birds learn to
sing only by imitating the adults, still holds its ground; and Darwin
gives it his approval in his 'Descent of Man'. It is perhaps one of
those doctrines which are partly true, or which do not contain the
whole truth; and it is possible to believe that, while many singing
birds do so learn their songs, or acquire a greater proficiency in them
from hearing the adults, in other species the song comes instinctively,
and is, like other instincts and habits, purely an 'inherited memory'."
What Dr. Hudson surmises may be the case, I believe my experiments have
proved to be true.