INSTINCT is the overworked and much abused word of many writers. As applied to the wild things, we often stumble on to the terms, instinct of direction, instinct of migration, instinct of song, instinct of nest building, and so on. Webster gives several definitions as to the meaning of instinct. The following covers the ground:
"An instinct is an agent which performs blindly and ignorantly a work of intelligence and knowledge.”
To gather acorns in the balmy days of October and store them for the cold of winter, is a work of intelligence and knowledge. Can we believe that the blue jays and squirrels perform this work blindly and ignorantly? If they do, then the storing of a single nut would be a miracle. Watch a red squirrel while gathering acorns and note carefully his intelligent acts. If there is a clear spot beneath the oak he drops the acorns on to it, even if he has to carry each nut from one side to the other of the tree. Note how carefully he selects the fruit: no wormy nuts are wanted. In fact, he exercises the same thoughtful care that a human being would exercise under like conditions. Does he do the work blindly?
Instinct, as applied to the lives of wild animals, is such an elusive and meaningless term, that it is a pity it should be used so often by writers on natural history. The word "instinct" savors of the supernatural, and was invented in ancient times to separate man from the brute, when the lower animals were supposed to lack reason. The word "heredity" is a far better word, for it renders intelligible all of fact that the word "instinct" implies, without resort to imagination and the supernatural.
It is claimed by some writers that the sense of direction is an instinct which guides birds in migration. As one writer states it: "They may be frightened and become confused, as by being frequently shot at, but once beyond the danger-line, their instinct regains control, and they will resume their journey in a direct line for their ultimate destination, and that, too, without stopping to think which way is the right way."
If this were true, if birds could launch themselves into the air and go South without thought, and, if turned aside, miraculously regain their course without a thought as to the right way, then indeed would I be forced to admit the supernatural, to acknowledge that the days of miracles were not past, but it would upset all my preconceived ideas of Dame Nature and her laws.
Really, before we resort to miracles to explain migration, would it not be well to turn to natural laws—laws that are explained by intelligent thought after careful observation?
I have ever found the birds as intelligent in relation to the needs of their lives as we are to our lives. Migration is not an exception to the rule.
If man migrates he does so intelligently. Why not grant to birds the same faculty?
For the sake of illustration we will take the swallows, birds known to all, and describe their method of migration. Remember, that the old birds have been South, that they know the way and do not doubt their ability to pilot the young birds to the new home. They also know, from experience, the perils and hardships of a long flight while battling with wind and weather. Full well they know that young birds, just out of the nest, would not last a day's flight if raw and untrained. So they intelligently proceed to train the young birds into a suitable condition. Early in the morning, after the young are fed, they are marshalled along the wires and fences and drilled in the art of flying. At first they fly in small squads, just a family group, but later they gather into companies and practise until the companies are massed in one grand army corps. When the young birds are thoroughly drilled, that is, are hard of muscle and capable of keeping their place in the ranks, to touch elbows, as it were, the old birds are ready to lead the way South. To avoid straggling the departure is made in the night.
Up to this point we see no indications of instinct. The acts of the swallows are as intelligent as would be the acts of human beings under like circumstances. If a general had raw recruits to deal with he would drill them just as the swallows drill their raw recruits.
Perhaps the manœuvres of swallows gave mankind the idea of military tactics.
When we consider the journey of these birds South, why should we claim that their acts are guided by a supernatural power? Why not allow intelligence in flight as well as in preparing for flight?
We can readily understand how the old birds, that have made several journeys and must be familiar with all the landmarks, may make the journey without the aid of a supernatural power.
We must remember that the sense of sight in birds is developed to a degree unknown to mankind. It often happens that I startle a ruffed grouse from its perch in the night. In such case it hurls itself through the shrubbery with amazing speed. When I think of the keenness of sight that enables this bird to avoid twigs and limbs, I know that my sight is nothing but blindness in comparison.
Some birds fly high, and the earth is like a map beneath them, with a well-defined line between land and water. Birds that are familiar with the route ought to experience no difficulty in finding the way. Even the limited sight of man would serve unless handicapped by a dark, stormy night.
Young birds left to themselves will not go South. Young robins often get left in this vicinity. They are birds of the last brood usually; the parent birds are killed before the young learn to associate with the flocks in the neighborhood. They stay through the winter because they have no knowledge of the South and no guide to lead the way. Ducks hatched under hens from wild eggs will not go South. I once lived near a farmer that hatched out six black ducks. The farmer did not feed them, and they lived through the summer on a trout brook. In winter they huddled into a fence corner under some shrubbery. They had no instinct to send them South, although their flight feathers were perfect; but they possessed intelligence enough to seek the cattle tie-up for warmth whenever they found the door open.
It is assumed that the bee, the pigeon, and some variety of ducks, rise and circle in the air to leave landmarks "out of sight," so that this remarkable instinct may work more freely. Would it not be well to apply natural laws to these cases? Suppose we infer that these animals rise and circle to find familiar landmarks, just as a human being would act if he had the power of flight and had lost his way. Human beings climb trees, when lost, to look for landmarks. Why should we deny to bees and birds the very methods we make use of whenever the occasion requires?
As to bees, I do know that they circle to find landmarks. After years spent in hunting, or "lining bees," as we call the sport in Maine, I can speak with no uncertain knowledge. The power to circle in search of landmarks is limited. If a bee is carried too far from its hive, beyond its power to circle and find landmarks, it is lost and never returns to the hive. I have proved this time after time. The carrier-pigeon's power to circle is a most remarkable feature, but nevertheless it has its limit. Pigeons that are used for long-distance flight are trained over the whole distance in short flights, so the bird may become familiar with landmarks.
Our dogs and cats that return to us when carried sightless to a distance, may return through the sense of smell. Cape Ann fishermen tell me that dogs scent the land fifty miles at sea. If we grant to animals the power of observation which we possess, and then take into consideration their keen sense of smell, we can account for many things that seem mysterious. However, dogs and cats are lost every day in the week.
Nest building is said to be instinctive, but I shall have to take exceptions to the statement. I do not deny that the art is hereditary, and that a young bird confined might essay to build something for a nest, but I do deny that the selection of straws is under the influence of instinct. I believe young birds examine the nest in which they are reared intelligently, and are educated by their parents in part in the selection of material. I once saw an old catbird give her young daughter a lesson in nest building. The young catbird had carried a large quantity of rootlets from my garden to a patch of catbrier. She had placed it so loosely that a good breeze would have upset the whole affair. While I was looking on wondering what the bird would do if the wind should rise, the old catbird, the young bird's mother, happened along to inspect the work.
The moment she saw the shaky structure she tumbled it on to the ground. Then she laid a foundation that no breeze could dislodge. Her selection of rootlets long enough to bridge the spaces was something wonderful. I did not see her make a mistake. If she picked up a rootlet a hair's breadth short, she dropped it for another of the right length. After she had laid a secure foundation, she left the young bird to her own skill and judgment. When the bird had completed the nest, it was as large as a four-quart measure. It was made up of varied materials. Newspaper and cloth afforded the larger amount. A departure was the skin of a garter snake woven into the brim. A few years ago I found a catbird's nest ornamented with a snake-skin, and the two instances are the only ones of all my observations.
WOOD THRUSH.
To read some of our books on ornithology, would lead one to suppose that birds of the same species constructed nests exactly alike, but the fact is, that no two nests are alike. A bird will improve in nest building, usually, with age. I have a little friend, a chestnut-sided warbler, that has constructed twenty-three nests since I made her acquaintance. As I remember them the last nest is the neatest and most substantial. Some have been made almost wholly of rags. Chickadees have adopted cotton-batting, and call for it if I neglect to keep it in the dooryard. It often happens that birds select new material, if handy, instead of hunting the usual nest building material. If birds were guided by instinct and did not exercise reason, they would select the same nesting material year after year. The habit would be so securely fixed that the bird would not be tempted to use new material, no matter how plentiful or handy it might be. The fact that birds readily accommodate themselves to new surroundings, is proof positive that they possess the power to reason. I found a nest, last season, of the wood-thrush, which was a complete departure from the usual nest. The bulk of the nest was composed of moss, sphagnum. It was placed on some bushes of the black-alder which the snow had bent down. Instead of mud the bird had used a black soil, and the nest was lined with horsehair. The horsehair, moss, and black mold were all near the nest. If I had found the nest after the young had left it, it would have proved a puzzle for me. As it was, the old bird was on the nest when I found it and so gave me the clue.
Young birds are taught to sing by the old males. This is true of the birds that have come under my observation. Even the grouse teaches the young to drum. This is done soon after dark in the fall of the year. From my hammock I often hear these lessons. The old grouse makes the woods ring with his drumming. Then he rests while the young grouse try a hand. Their efforts are not a success, and the old bird again shows them how to do it. Some nights this will go on for two hours.
There is a test that any one can try, to prove that song is educational and not instinctive.
Go into the woods inhabited by the wood-thrush, and sit down and listen. It will soon be evident that you have invited yourself to a bird's singing school.
In a party of summer residents from Magnolia, there was one lady who told me she had no patience with my views on song. That a bird would sing, anyway, because it had a throat adapted to song. She said that when I heard birds sing out of season, I would claim that they were teaching their young, when in fact they were only exercising their voices without a thought of teaching. When they were ready to return to Magnolia, I offered to show them a path through the woods, a new way to them. When I had reached a spot where I knew there was a family of wood-thrushes, I ordered a rest. When we had become quiet the old thrush tuned up and gave us the song. It is a short song, but loud, clear, and flute-like. There was no wind, and the song appeared to be sweeter and louder than usual. When the old thrush had ceased, one young bird after another took up the strain. Some would give one note, others two or three notes. Some notes would be hoarse, others would be shrill. After awhile the birds would forget the lesson and drop out one after the other. When all were silent, the old thrush would again give them the right pitch and tone, and again the young thrushes tried to imitate the singer. For two hours we sat there and listened. The lady had to admit that the old bird was giving the young birds a lesson. Yet she claimed that the thrush was an exception. I was glad that she was ready to admit that one bird of a species was intelligent. I told her that when she had devoted two hours to all the other birds she would be converted to my faith.
THE HERMIT THRUSH.
Of all the thrushes the Hermit is my favorite. Not because he is a namesake, but for the reason that his is one of the beautiful bird-songs woven into the memory of my boyhood days. I see him here only in migration. The last of March or first of April, I see the bird, and hear the sweet "Tu-le, tu-li-le." A beautiful strain, but only the prelude to the true song, which is seldom heard away from their summer home. Years ago I wrote the following description of the song of the hermit-thrush :
"To me the song of the hermit-thrush is the sweetest sound in nature. It is not a plaintive, pensive, or tender strain, but satisfies the senses and clings to the memory like the recollection of some great joy.
"I shall never forget a song I once heard in the woods of northern Maine. I was in a bark-peeling camp at the time. A rainy day had sent the crew to their homes in the settlement until the next morning; and I was left alone.
"The rain poured down in torrents. The wind howled and roared through the tree-tops, flinging great sheets of water on to the bark roof of the camp. My spirits were depressed and gloomy. Financial troubles, the loss of a cherished home, had disheartened me, and life seemed hardly worth living.
"Just before night the rain suddenly ceased. The sun burst through the clouds, and the wind completely died out. Save for the sound of dropping water, the forest was silent and solemn. A glowing sunset, painting all the clouds of the western sky, aroused me from my miserable thoughts. Just then the song of the hermit-thrush floated up from a neighboring swamp. Clear and pure the flute-like notes slowly echoed through the silent woods. The moist and hollow atmosphere magnified the slightest sound, and I could distinguish the fine trills which form a part of this famous song. 'O, phee-re-al, phee-re-al!' represents the strain as near as I can give it in words.
"I would that I were able to express in fitting language the feelings with which I am inspired when I listen to the song of the hermit-thrush. It satisfies my sense of the beautiful as no other song can. And yet I am never quite satisfied. There is something I do not understand. Something beyond me, a shadowy mystery. After I have listened to the strain, and while its memory still lingers, I find myself longing to know the whole secret of its charm. However, years ago I settled the matter in my mind and note-book, as the following entry will show: 'The song of the hermit-thrush is the Spirit of Nature chanting the mystery of life. When the mystery is solved we shall understand the song.’
"Day faded into twilight, and twilight into night, and still that exalted anthem solemnly pealed through the forest. It was after ten o'clock when the strain died out in a few broken notes.
"Thanks to the hermit-thrush, my thoughts were turned into a new and healthy channel. I fell asleep that night on my fragrant bed of fir-boughs, at peace with the whole world.”