Ways of Nature

by John Burroughs

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!