III ILS N’ONT QUE DE L’ÂME: AN ESSAY ON BIRD-MIND
THE BIRDS
To most of us, a bird’s a feathered song
Which for our pleasure gives a voice to spring.
We make a symbol of its airy wing
Bright with the liberty for which we long.
Or we discover them with love more strong
As each a separate, individual thing
Which only learns to act, or move, or sing
In ways that wholly to itself belong.
But some with deeper and more inward sight
See them a part of that one Life which streams
Slow on, towards more mind—a part more light
Then we; unburdened with regrets, or dreams,
Or thought. A winged emotion of the sky,
The birds through an eternal Present fly.
Oxford, April 1923.
ILS N’ONT QUE DE L’ÂME:
AN ESSAY ON BIRD-MIND
“O Nightingale, thou surely art
A creature of a fiery heart.”
—W. Wordsworth.
“The inferior animals, when the conditions of life are favourable, are subject to periodical fits of gladness, affecting them powerfully and standing out in vivid contrast to their ordinary temper.... Birds are more subject to this universal joyous instinct than mammals, and ... as they are much freer than mammals, more buoyant and graceful in action, more loquacious, and have voices so much finer, their gladness shows itself in a greater variety of ways, with more regular and beautiful motions, and with melody.”—W. H. Hudson.
“How do you know but ev’ry Bird that cuts the airy way
Is an immense world of delight, clos’d by your senses five?”
—Blake.
“Ils n’ont pas de cerveau—ils n’ont que de l’âme.” A dog was being described, with all his emotion, his apparent passion to make himself understood, his failure to reach comprehension; and that was how the French man of letters summed up the brute creation—“pas de cerveau—que de l’âme.”
Nor is it a paradox: it is a half-truth that is more than half true—more true at least than its converse, which many hold.
There is a large school to-day who assert that animals are “mere machines.” Machines they may be: it is the qualification which does not fit. I suppose that by saying “mere” machines it is meant to imply that they have the soulless, steely quality of a machine which goes when it is set going, stops when another lever is turned, acts only in obedience to outer stimuli, and is in fact unemotional—a bundle of operations without any quality meriting the name of a self.
It is true that the further we push our analysis of animal behaviour, the more we find it composed of a series of automatisms, the more we see it rigorously determined by combination of inner constitution and outer circumstance, the more we have cause to deny to animals the possession of anything deserving the name of reason, ideals, or abstract thought. The more, in fact, do they appear to us as mechanisms (which is a much better word than machines, since this latter carries with it definite connotations of metal or wood, electricity or steam). They are mechanisms, because their mode of operation is regular; but they differ from any other type of mechanism known to us in that their working is—to put it in the most non-committal way—accompanied by emotion. It is, to be sure, a combination of emotion with reason that we attribute to a soul; but none the less, in popular parlance at least, the emotional side is predominant, and pure reason is set over against the emotional content which gives soul its essence. And this emotional content we most definitely find running through the lives of higher animals.
The objection is easily and often raised that we have no direct knowledge of emotion in an animal, no direct proof of the existence of any purely mental process in its life. But this is as easily laid as raised. We have no direct knowledge of emotion or any other conscious process in the life of any human being save our individual selves; and yet we feel no hesitation in deducing it from others’ behaviour. Although it is an arguable point whether biological science may not for the moment be better served by confining the subject-matter and terms of analysis to behaviour alone, it is a very foolhardy “behaviorist” indeed who denies the existence of emotion and conscious process!
But the practical value of this method of thinking is, as I say, an arguable point; it is indeed clear that a great immediate advance, especially in non-human biology, has been and may still be made by translating the uncertain and often risky terms of subjective psychology into those based upon the objective description of directly observable behaviour. However, it is equally easy to maintain, and I for one maintain it, that to omit a whole category of phenomena from consideration is unscientific, and must in the long run lead to an unreal, because limited, view of things; and that, when great detail of analysis is not required, but only broad lines and general comparison, the psychological terminology, of memory, fear, anger, curiosity, affection, is the simpler and more direct tool, and should be used to supplement and make more real the cumbersome and less complete behavioristic terminology, of modification of behaviour, fright, aggression, and the rest.
It is at least abundantly clear that, if we are to believe in the principle of uniformity at all, we must ascribe emotion to animals as well as to men: the similarity of behaviour is so great that to assert the absence of a whole class of phenomena in one case, its presence in the other, is to make scientific reasoning a farce.
“Pas de cerveau—que de l’âme.” Those especially who have studied birds will subscribe to this. The variety of their emotions is greater, their intensity more striking, than in four-footed beasts, while their power of modifying behaviour by experience is less, the subjection to instinct more complete. Those who are interested in the details can see from experiments, such as those recorded by Mr. Eliot Howard in his Territory in Bird Life, how limited is a bird’s power of adjustment; but I will content myself with a single example, one of nature’s experiments, recorded by Mr. Chance last year by the aid of the cinematograph—the behaviour of small birds when the routine of their life is upset by the presence of a young Cuckoo in the nest.
When, after prodigious exertions, the unfledged Cuckoo has ejected its foster-brothers and sisters from their home, it sometimes happens that one of them is caught on or close to the rim of the nest. One such case was recorded by Mr. Chance’s camera. The unfortunate fledgling scrambled about on the branches below the nest; the parent Pipit flew back with food; the cries and open mouth of the ejected bird attracted attention, and it was fed; and the mother then settled down upon the nest as if all was in normal order. Meanwhile, the movements of the fledgling in the foreground grew feebler, and one could imagine its voice quavering off, fainter and fainter, as its vital warmth departed. At the next return of the parent with food the young one was dead.
It was the utter stupidity of the mother that was so impressive—its simple response to stimulus—of feeding to the stimulus of the young’s cry and open mouth, of brooding to that of the nest with something warm and feathery contained in it—its neglect of any steps whatsoever to restore the fallen nestling to safety. It was almost as pitiable an exhibition of unreason as the well-attested case of the wasp attendant on a wasp-grub, who, on being kept without food for some time, grew more and more restless, and eventually bit off the hind end of the grub and offered it to what was left!
Birds in general are stupid, in the sense of being little able to meet unforeseen emergencies; but their lives are often emotional, and their emotions are richly and finely expressed. I have for years been interested in observing the courtship and the relations of the sexes in birds, and have in my head a number of pictures of their notable and dramatic moments. These seem to me to illustrate so well the emotional furnishing of birds, and to provide such a number of windows into that strange thing we call a bird’s mind, that I shall simply set some of them down as they come to me.
First, then, the coastal plain of Louisiana; a pond, made and kept as a sanctuary by that public-spirited bird-lover Mr. E. A. McIlhenny, filled with noisy crowds of Egrets and little egret-like Herons. These, in great flocks, fly back across the “Mexique Bay” in the spring months from their winter quarters in South America. Arrived in Louisiana, they feed and roost in flocks for a time, but gradually split up into pairs. Each pair, detaching themselves from the flocks, choose a nesting-site (by joint deliberation) among the willows and maples of the breeding pond. And then follows a curious phenomenon. Instead of proceeding at once to biological business in the shape of nest-building and egg-laying, they indulge in what can only be styled a honeymoon. For three or four days both members of the pair are always on the chosen spot, save for the necessary visits which they alternately pay to the distant feeding grounds. When both are there, they will spend hours at a time sitting quite still, just touching one another. Generally the hen sits on a lower branch, resting her head against the cock bird’s flanks; they look for all the world like one of those inarticulate but happy couples upon a bench in the park in spring. Now and again, however, this passivity of sentiment gives place to wild excitement. Upon some unascertainable cause the two birds raise their necks and wings, and, with loud cries, intertwine their necks. This is so remarkable a sight that the first time I witnessed it I did not fully credit it, and only after it had happened before my eyes on three or four separate occasions was I forced to admit it as a regular occurrence in their lives. The long necks are so flexible that they can and do make a complete single turn round each other—a real true-lover’s-knot! This once accomplished, each bird then—most wonderful of all—runs its beak quickly and amorously through the just raised aigrettes of the other, again and again, nibbling and clappering them from base to tip. Of this I can only say that it seemed to bring such a pitch of emotion that I could have wished to be a Heron that I might experience it. This over, they would untwist their necks and subside once more into their usual quieter sentimentality.
This, alas! I never saw with the less common little White Egrets, but with the Louisiana Heron (which should, strictly speaking, be called an egret too); but since every other action of the two species is (in all save a few minor details) the same, I assume that the flashing white, as well as the slate and vinous and grey birds, behave thus.
The greeting ceremony when one bird of the pair, after having been away at the feeding grounds, rejoins its mate is also beautiful. Some little time before the human watcher notes the other’s approach, the waiting bird rises on its branch, arches and spreads its wings, lifts its aigrettes into a fan and its head-plumes into a crown, bristles up the feathers of its neck, and emits again and again a hoarse cry. The other approaches, settles in the branches near by, puts itself into a similar position, and advances towards its mate; and after a short excited space they settle down close together. This type of greeting is repeated every day until the young leave the nest; for after the eggs are laid both sexes brood, and there is a nest-relief four times in every twenty-four hours. Each time the same attitudes, the same cries, the same excitement; only now at the end of it all, one steps off the nest, the other on. One might suppose that this closed the performance. But no: the bird that has been relieved is still apparently animated by stores of unexpended emotion; it searches about for a twig, breaks it off or picks it up, and returns with it in beak to present to the other. During the presentation the greeting ceremony is again gone through; after each relief the whole business of presentation and greeting may be repeated two, or four, or up even to ten or eleven times before the free bird flies away.
When there are numerous repetitions of the ceremony, it is extremely interesting to watch the progressive extinction of excitement. During the last one or two presentations the twig-bringing bird may scarcely raise his wings or plumes, and will often betray an absent air, turning his head in the direction in which he is proposing to fly off.
No one who has seen a pair of Egrets thus change places on the nest, bodies bowed forward, plumes a cloudy fan of lace, absolute whiteness of plumage relieved by gold of eye and lore and black of bill, and the whole scene animated by the repeated, excited cry, can ever forget it. But such unforgettable scenes are not confined to other countries. Here in England you can see as good; I have seen them on the reservoirs of Tring, and within full view of the road by Frensham Pond—the courtship forms and dances of the Crested Grebe.
The Crested Grebe is happily becoming more familiar to bird-lovers in England. Its brilliant white belly, protective grey-brown back, rippleless and effortless diving, long neck, and splendid ruff and ear-tufts of black, chestnut, and white, conspire to make it a marked bird. In the winter the crest is small, and even when fully grown in spring it is usually held close down against the head, so as to be not at all conspicuous. When it is spread, it is almost, without exception, in the service of courtship or love-making. Ten years ago I spent my spring holiday watching these birds on the Tring reservoirs. I soon found out that their courtship, like the Herons’, was mutual, not one-sidedly masculine as in Peacocks or fowls. It consisted most commonly in a little ceremony of head-shaking. The birds of a pair come close, face one another, raise their necks, and half-spread their ruffs. Then, with a little barking note, they shake their heads rapidly, following this by a slow swinging of them from side to side. This alternate shaking and swinging continues perhaps a dozen or twenty times; and the birds then lower their standards, become normal everyday creatures, and betake themselves to their fishing or resting or preening again. This is the commonest bit of love-making; but now and then the excitement evident even in these somewhat casual ceremonies is raised to greater heights and seems to reinforce itself. The little bouts of shaking are repeated again and again. I have seen over eighty succeed each other uninterruptedly. And at the close the birds do not relapse into ordinary life. Instead, they raise their ruffs still further, making them almost Elizabethan in shape. Then one bird dives; then the other: the seconds pass. At last, after perhaps half or three-quarters of a minute (half a minute is a long time when one is thus waiting for a bird’s reappearance!) one after the other they emerge. Both hold masses of dark brownish-green weed, torn from the bottom of the pond, in their beaks, and carry their heads down and back on their shoulders, so that either can scarcely see anything of the other confronting it save the concentric colours of the raised ruff. In this position they swim together. It is interesting to see the eager looks of the first-emerged, and its immediate start towards the second when it too reappears. They approach, rapidly, until the watcher wonders what will be done to avert a collision. The answer is simple: there is no averting of a collision! But the collision is executed in a remarkable way: the two birds, when close to each other, leap up from the water and meet breast to breast, almost vertical, suddenly revealing the whole flashing white under-surface. They keep themselves in this position by violent splashings of the feet, rocking a little from side to side as if dancing, and very gradually sinking down (always touching with their breasts) towards the horizontal.
Meanwhile, they exchange some of the weed they are carrying; or at least nibbling and quick movements of the head are going on. And so they settle down on to the water, shake their heads a few times more, and separate, changing back from these performers of an amazing age-old rite—age-old but ever fresh—into the feeding- and sleeping-machines of every day, but leaving a vision of strong emotion, canalized into the particular forms of this dive and dance. The whole performance impresses the watcher not only with its strength, but as being apparently of very little direct (though possibly much indirect) biological advantage, the action being self-exhausting, not stimulating to further sexual relations, and carried out, it would seem, for its own sake.
Further acquaintance with the Grebe only deepened the interest and made clearer the emotional tinge underlying all the relations of the sexes. This bird, too, has its “greeting ceremony”; but since, unlike the colonial Herons and Egrets, it makes every effort to conceal its nest, this cannot take place at its most natural moment, that of nest-relief, but must be made to happen out on the open water where there are no secrets to betray. If the sitting bird wishes to leave the nest, and the other does not return, it flies off, after covering the eggs with weed, in search of its mate; it is common in the breeding season to see a Grebe in the “search-attitude,” with neck stretched up and slightly forward and ear-tufts erected, emitting a special and far-carrying call. When this call is recognized and answered, the two birds do nothing so simple as to fly or swim to each other, but a special and obviously exciting ceremony is gone through. The bird that has been searched for and found puts itself into a very beautiful attitude, with wings half-spread and set at right angles to the body, ruff erected circularly, and head drawn back upon the shoulders, so that nothing is visible but the brilliant rosette of the spread ruff in the centre of the screen of wings, each wing showing a broad bar of brilliant white on its dusk-grey surface. In this position it swings restlessly back and forth in small arcs, facing towards its mate. The discoverer meanwhile has dived; but, swimming immediately below the surface of the water, its progress can be traced by the arrowy ripple it raises. Now and again it lifts its head and neck above the water, periscope-wise, to assure itself of its direction, and resumes its subaqueous course. Nor does it rise just in front of the other bird; but swims under and just beyond, and, as its mate swings round to the new orientation, emerges in a really extraordinary attitude. At the last it must have dived a little deeper; for now it appears perpendicularly from the water, with a slowish motion, slightly spiral, the beak and head pressed down along the front of the neck. I compared it in my notes of ten years ago with “the ghost of a Penguin,” and that comparison is still the best I can think of to give some idea of the strange unreality of its appearance. It then settles down upon the water and the pair indulge in one of their never-failing bouts of head-shaking.
Two mated birds rejoin each other after a few hours’ separation. Simple enough in itself—but what elaboration of detail, what piling on of little excitements, what purveying of thrills!
Other emotions too can be well studied in this bird, notably jealousy. Several times I have seen little scenes like the following enacted. A pair is floating idly side by side, necks drawn right down so that the head rests on the centre of the back. One—generally, I must admit, it has been the cock, but I think the hen may do so too on occasion—rouses himself from the pleasant lethargy, swims up to his mate, places himself in front of her, and gives a definite, if repressed, shake of the head. It is an obvious sign of his desire to “have a bit of fun”—to go through with one of those bouts of display and head-shaking in which pleasurable emotion clearly reaches its highest level in the birds’ lives, as any one who has watched their habits with any thoroughness would agree. It also acts, by a simple extension of function, as an informative symbol. The other bird knows what is meant; it raises its head from beneath its wing, gives a sleepy, barely discernible shake—and replaces the head. In so doing it puts back the possibility of the ceremony and the thrill into its slumbers; for it takes two to make love, for Grebe as for human. The cock swims off; but he has a restless air, and in a minute or so is back again, and the same series of events is run through. This may be repeated three or four times.
If now another hen bird, unaccompanied by a mate, reveals herself to the eye of the restless and disappointed cock, he will make for her and try the same insinuating informative head-shake on her; and, in the cases that I have seen, she has responded, and a bout of shaking has begun. Flirtation—illicit love, if you will; for the Grebe, during each breeding season at least, is strictly monogamous, and the whole economics of its family life, if I may use the expression, are based on the co-operation of male and female in incubation and the feeding and care of the young. On the other hand, how natural and how human! and how harmless—for there is no evidence that the pretty thrills of the head-shaking display ever lead on to anything more serious.
But now observe. Every time that I have seen such a flirtation start, it has always been interrupted. The mate, so sleepy before, yet must have had one eye open all the time. She is at once aroused to action: she dives, and attacks the strange hen after the fashion of Grebes, from below, with an underwater thrust of the sharp beak in the belly. Whether the thrust ever goes home I do not know. Generally, I think, the offending bird becomes aware of the danger just in time, and, squawking, hastily flaps off. The rightful mate emerges. What does she do now? Peck the erring husband? Leave him in chilly disgrace? Not a bit of it! She approaches with an eager note, and in a moment the two are hard at it, shaking their heads; and, indeed, on such occasions you may see more vigour and excitement thrown into the ceremony than at any other time.
Again we exclaim, how human! And again we see to what a pitch of complexity the bird’s emotional life is tuned.
It will have been observed that in the Grebe, whose chief skill lies in its wonderful powers of diving, these powers have been utilized as the raw material of several of the courtship ceremonies. This pressing of the everyday faculties of the bird into the service of emotion, the elevation and conversion of its useful powers of diving and underwater swimming into ceremonials of passion, is from an evolutionary point of view natural enough, and has its counterparts elsewhere. So in the Divers, not too distant relatives of the Grebes, swimming and diving have their rôle in courtship. Here too the thrilling, vertical emergence close to the mate takes place; and there is a strange ceremony in which two or three birds plough their way through the water with body set obliquely—hinder parts submerged, breast raised, and neck stretched forward and head downward with that strange look of rigidity or tension often seen in the courtship actions of birds.
Or, again, I once saw (strangely enough from the windows of the Headmaster’s house at Radley!) the aerial powers of the Kestrel converted to the uses of courtship. The hen bird was sitting in a large bush beyond the lawn. A strong wind was blowing, and the cock again and again beat his way up against it, to turn when nearly at the house and bear down upon the bush in an extremity of speed. Just when it seemed inevitable that he would knock his mate off her perch and dash himself and her into the branches, he changed the angle of his wings to shoot vertically up the face of the bush; then turned and repeated the play. Sometimes he came so near to her that she would start back, flapping her wings, as if really fearing a collision. The wind was so strong—and blowing away from me—that I could not hear what cries may have accompanied the display.
A friend of mine who knows the Welsh mountains and is a watcher of birds as well, tells me that he has there seen the Peregrine Falcons do the same thing: the same thing—except that the speed was perhaps twice as great, and the background a savage rock precipice instead of a Berkshire garden.
Not only the activities of everyday life, but also those of nest-building, are taken and used to build up the ceremonies of courtship; but whereas in the former case the actions are simply those which are most natural to and best performed by the bird, in the latter there is, no doubt, actual association between the cerebral centres concerned with nest-building and with sexual emotion in general. Thus we almost invariably find the seizing of nest-material in the beak as a part of courtship, and this is often extended to a presentation of the material to the mate. This we see in the Grebes, with the dank weeds of which their sodden nest is built; the Divers use moss in the construction of theirs, and the mated birds repair to moss banks, where they nervously pluck the moss, only to drop it again or throw it over their shoulder. Among the Warblers, the males pluck or pick up a leaf or twig, and with this in their beak hop and display before the hens; and the Peewit plucks frenziedly at grass and straws. The Adelie Penguins, so well described by Dr. Levick, make their nests of stones, and use stones in their courtship.
A curious, unnatural transference of object may sometimes be seen in these Penguins. The normal course of things is for this brave but comic creature, having picked up a stone in its beak, to come up before another of opposite sex, and, with stiff bow and absurdly outstretched flippers, to deposit it at the other’s feet. When, however, there are men near the rookery, the birds will sometimes in all solemnity come up to them with their stone offering and lay it at the feet of the embarrassed or amused human being.
The Adelies do not nest by their natural element the sea, but some way away from it on stony slopes and rock patches; thus they cannot employ their brilliant dives and feats of swimming in courtship, but content themselves, apart from this presentation of household material, with what Dr. Levick describes as “going into ecstasy”—spreading their flippers sideways, raising their head quite straight upwards, and emitting a low humming sound. This a bird may do when alone, or the two birds of a pair may make a duet of it. In any case, the term applied to it by its observer well indicates the state of emotion which it suggests and no doubt expresses.
The depositing of courtship offerings before men by the Penguins shows us that there must be a certain freedom of mental connection in birds. Here an act, properly belonging to courtship, is performed as the outlet, as it were, of another and unusual emotion. The same is seen in many song-birds, who, like the Sedge Warbler, sing loudly for anger when disturbed near their nest; or in the Divers, who, when an enemy is close to the nest, express the violence of their emotion by short sharp dives which flip a fountain of spray into the air—a type of dive also used as a sign of general excitement in courtship.
Or, again, the actions may be performed for their own sake, as we may say: because their performance, when the bird is full of energy and outer conditions are favourable, gives pleasure. The best-known example is the song of song-birds. This, as Eliot Howard has abundantly shown, is in its origin and essential function a symbol of possession, of a nesting territory occupied by a male—to other males a notice that “trespassers will be prosecuted,” to females an invitation to settle, pair, and nest. But in all song-birds, practically without exception, the song is by no means confined to the short period during which it actually performs these functions, but is continued until the young are hatched, often to be taken up again when they have flown, or after the moult, or even, as in the Song Thrush, on almost any sunny or warm day the year round.
And finally this leads on to what is perhaps the most interesting category of birds’ actions—those which are not merely sometimes performed for their own sake, although they possess other and utilitarian function, but actually have no other origin or raison d’être than to be performed for their own sake. They represent, in fact, true play or sport among ourselves; and seem better developed among birds than among mammals, or at least than among mammals below the monkey. True that the cat plays with the mouse, and many young mammals, like kittens, lambs, and kids, are full of play; but the playing with the mouse is more like the singing of birds outside the mating season, a transference of a normal activity to the plane of play; and the play of young animals, as Groos successfully exerted himself to show, is of undoubted use. To be sure, the impulse to play must be felt by the young creature as an exuberance of emotion and spirits demanding expression; but a similar impulse must be felt for all instinctive actions. Psychologically and individually, if you like, the action is performed for its own sake; but from the standpoint of evolution and of the race it has been originated, or at least perfected, as a practice ground for immature limbs and a training and keeping ready of faculties that in the future will be needed in earnest.
We shall best see the difference between mammals’ and birds’ behaviour by giving some examples. A very strange one I saw in a pond near the Egret rookery in Louisiana. Here, among other interesting birds, were the Darters or Water Turkeys, curious-looking relatives of the Cormorants, with long, thin, flexible neck, tiny head, and sharp beak, who often swim with all the body submerged, showing nothing but the snake-like neck above water. One of these was sitting on a branch of swamp-cedar, solitary and apparently tranquil. But this tranquillity must have been the cloak of boredom. For suddenly the bird, looking restlessly about her (it was a hen), began to pluck at the little green twigs near by. She pulled one off in her beak, and then, tossing her head up, threw it into the air, and with dexterous twist caught it again in her beak as it descended. After five or six successful catches she missed the twig. A comic sideways and downward glance at the twig, falling and fallen, in meditative immobility; and then another twig was broken off, and the same game repeated. She was very clever at catching; the only bird that I have seen come up to her was a Toucan in the Zoo which could catch grapes thrown at apparently any speed. But then the Toucan had been specially trained—and had the advantage of a huge capacity of bill!
Here again it might, of course, be said that the catching of twigs is a practice for beak and eye, and helps keep the bird in training for the serious business of catching fish. This is no doubt true; but, as regards the evolution of the habit, I incline strongly to the belief that it must be quite secondary—that the bird, desirous of occupying its restless self in a satisfying way, fell back upon a modification of its everyday activities, just as these are drawn upon in other birds to provide much of the raw material of courtship. There is no evidence that young Darters play at catching twigs as preparation for their fishing, and until there is evidence of this it is simpler to think that the play habit here, instead of being rooted by the utilitarian dictates of natural selection in the behaviour of the species, as with kids or kittens, is a secondary outcome of leisure and restlessness combining to operate with natural aptitude—in other words, true sport, of however simple a kind.
The commonest form of play in birds is flying play. Any one who has kept his eyes open at the seaside will have seen the Herring Gulls congregate in soaring intersecting spirals where the cliff sends the wind upwards. But such flights are nothing compared with those of other birds. Even the staid black-coated Raven may sometimes be seen to go through a curious performance. One I remember, all alone, flying along the side of a mountain near Oban; but instead of progressing in the conventional way, he flew diagonally upwards for a short distance, then giving a special croak with something of gusto in it, turned almost completely over on to his back, and descended a corresponding diagonal in this position. Then with a strong flap of the wings he righted himself, and so continued until he disappeared round the shoulder of the hill half a mile on. It reminded me of a child who has learnt some new little trick of step or dance-rhythm, and tries it out happily all the way home along the road. Mr. Harold Massingham has seen the Ravens’ games too, and set them down more vividly than I can.[26] He also is clear that they play for the love of playing, and even believes that their love of sport has helped their downfall to rarity by rendering them too easy targets for the gunner.
Or again, at the Egret rookery in Louisiana, at evening when the birds returned in great numbers, they came back with steady wing-beats along an aerial stratum about two hundred feet up. Arrived over their nesting pond, they simply let themselves drop. Their plumes flew up behind like a comet’s tail; they screamed aloud with excitement; and, not far above the level of the trees, spread the wings so that they caught the air again, and as result skidded and side-slipped in the wildest and most exciting-looking curves before recovering themselves with a brief upward glide and settling carefully on the branches. This certainly had no significance for courtship; and I never saw it done save over the pond at the birds’ return. It seemed to be simply an entertaining bit of sport grafted on to the dull necessity of descending a couple of hundred feet.
Examples could be multiplied: Rooks and Crows, our solemn English Heron, Curlew, Swifts, Snipe—these and many others have their own peculiar flying sports. What is clear to the watcher is the emotional basis of these sports—a joy in controlled performance, and excitement in rapidity of motion, in all essentials like the pleasure to us of a well-hit ball at golf, or the thrill of a rapid descent on sledge skis.
For any one to whom the evolution theory is one of the master-keys to animate nature, there must be an unusual interest in tracing out the development of lines of life that, like the birds’, have diverged comparatively early from the line which eventually and through many vicissitudes led to Man.
In the birds as in the mammals, and quite separately in the two groups, we see the evolution not only of certain structural characters such as division of heart, compactness of skeleton, increase of brain-size, not only of physiological characters like warm-bloodedness or efficiency of circulation, but also of various psychical characters. The power of profiting by experience becomes greater, as does that of distinguishing between objects; and there is most markedly an increase in the intensity of emotion. It has somehow been of advantage, direct or indirect, to birds to acquire a greater capacity for affection, for jealousy, for joy, for fear, for curiosity. In birds the advance on the intellectual side has been less, on the emotional side greater: so that we can study in them a part of the single stream of life where emotion, untrammelled by much reason, has the upper hand.