Animal Intelligence · George J. Romanes
ADEQUATELY to treat of the intelligence of birds a separate volume would be required; here it must be enough to deal with this class as I shall afterwards deal with the Mammalia--namely, by giving an outline sketch of the more prominent features of their psychology.
Memory._
The memory of birds is well developed. Thus, although we are much in the dark on the whole subject of migration--so much so that I reserve its discussion with all the problems that this presents for a separate chapter in my next work--we may at least conclude that the return of the same pair of swallows every year to the same nest must be due to the animals remembering the precise locality of their nests. Again, Buckland gives an account of a pigeon which remembered the voice of its mistress after an absence of eighteen months; but I have not been able to meet with satisfactory evidence of the memory of a bird enduring for a longer time than this.
As it is a matter of interest in comparative psychology to trace as far as possible into detail the similarities of a mental faculty as it occurs in different groups of animals, and as the faculty of memory first admits of detailed study in the class which we are now considering, I shall here devote a paragraph to the facts concerning the exhibition of memory by birds where its mechanism best admits of being analysed; I refer to the learning of articulate phrases and tunes by talking and musical birds. The best observations in this connection with which I am acquainted are those of Dr. Samuel Wilks, F.R.S., and therefore I shall quote in extenso the portion of his paper which refers to the memory of parrots: other portions of this paper I shall have occasion to quote in my next work:--
When my parrot first came into my possession, several years ago, it was quite unlettered, and I therefore had an opportunity of observing the mode in which it acquired the accomplishment of speech. I was very much struck with its manner of learning, and the causes for its speaking on special occasions. The first seemed to resemble very much the method of children in learning their lessons, and the second to be due to some association or suggestion--the usual provocative for set speeches at all periods of human life. A parrot is well known to imitate sounds in a most perfect manner, even to the tone of the voice, besides having a compass which no human being can approach, ranging from the gravest to the most acute note. My bird, though possessing a good vocabulary of words and sentences, can only retain them for a few months unless kept constantly in practice by the suggestive recurrence of some circumstance which causes their continual utterance. If forgotten, however, they are soon revived in the memory by again repeating them a few times, and much more speedily than any new sentence can be acquired. In beginning to teach the parrot a sentence, it has to be repeated many times, the bird all the while listening most attentively by turning the opening of the ear as close as possible to the speaker. After a few hours it is heard attempting to say the phrase, or, I should say, trying to learn it. It evidently has the phrase somewhere in store, for eventually this is uttered perfectly, but at first the attempts are very poor and ludicrous. If the sentence be composed of a few words, the first two or three are said over and over again, and then another and another word added, until the sentence is complete, the pronunciation at first being very imperfect, and then becoming gradually more complete, until the task is accomplished. Thus hour after hour will the bird be indefatigably working at the sentence, and not until some days have elapsed will it be perfect. The mode of acquiring it seems to me exactly what I have observed in a child learning a French phrase; two or three words are constantly repeated, and then others added, until the whole is known, the pronunciation becoming more perfect as the repetition goes on. I found also on whistling a popular air to my parrot that she picked it up in the same way, taking note by note until the whole twenty-five notes were complete. Then the mode of forgetting, or the way in which phrases and airs pass from its recollection, may be worth remarking. The last words or notes are first forgotten, so that soon the sentence remains unfinished or the air only half whistled through. The first words are the best fixed in the memory; these suggest others which stand next to them, and so on till the last, which have the least hold on the brain. These, however, as I have before mentioned, can be easily revived on repetition. This is also a very usual process in the human subject: for example, an Englishman speaking French will, in his own country, if no opportunity occur for conversation, apparently forget it; he no sooner, however, crosses the Channel and hears the language than it very soon comes back to him again. In trying to recall poems learned in childhood or in school days, although at that period hundreds of lines may have been known, it is found that in manhood we remember only the two or three first lines of the 'Iliad,' the 'Æneid,' or the 'Paradise Lost.'
The following is communicated to me by Mr. Venn, of Cambridge, the well-known logician:--
I had a grey parrot, three or four years old, which had been taken from its nest in West Africa by those through whom I received it. It stood ordinarily by the window, where it could equally hear the front and back door bells. In the yard, by the back door, was a collie dog, who naturally barked violently at nearly all the comers that way. The parrot took to imitating the dog. After a time I was interested in observing the discriminative association between the back-door bell and the dog's bark in the parrot's mind. Even when the dog was not there, or for any other cause did not bark, the parrot would constantly bark when the back-door bell sounded, but never (that I could hear) when the front-door bell was heard.
This is but a trifle in the way of intelligence, but it struck me as an interesting analogous case to a law of association often noticed by writers on human psychology.
The celebrated parrot that belonged to the Buffon family and of which the Comte de Buffon wrote, exhibited in a strange manner the association of its ideas. For he was frequently in the habit of asking himself for his own claw, and then never failed to comply with his own request by holding it out, in the same way as he did when asked for his claw by anybody else. This, however, probably arose, not, as Buffon or his sister Madame Nadault supposed, from the bird not knowing its own voice, but rather from the association between the words and the gesture.
According to Margrave, parrots sometimes chatter their phrases in their dreams, and this shows a striking similarity of psychical processes in the operations of memory with those which occur in ourselves.
Similarly, Mr. Walter Pollock, writes me of his own parrot:--
In this parrot the sense of association is very strongly developed. If one word picked up at a former home comes into its head, and is uttered by it, it immediately follows this word up with all the other words and phrases picked up at the same place and period.
Lastly, parrots not only remember, but recollect; that is to say, they know when there is a missing link in a train of association, and purposely endeavour to pick it up. Thus, for instance, the late Lady Napier told me an interesting series of observations on this point which she had made upon an intelligent parrot of her own. They were of this kind. Taking such a phrase as 'Old Dan Tucker,' the bird would remember the beginning and the end, and try to recollect the middle. For it would say very slowly, 'Old--old--old--old' (and then very quickly) 'Lucy Tucker.' Feeling that this was not right, it would try again as before, 'Old--old--old--old--old Bessy Tucker,' substituting one word after another in the place of the sought-for word 'Dan.' And that the process was one of truly seeking for the desired word was proved by the fact that if, while the bird was saying, 'Old--old--old--old,' any one threw in the word 'Dan,' he immediately supplied the 'Tucker.'
Emotions._
As regards emotions, it is among birds that we first meet with a conspicuous advance in the tenderer feelings of affection and sympathy. Those relating to the sexes and the care of progeny are in this class proverbial for their intensity, offering, in fact, a favourite type for the poet and moralist. The pining of the 'love-bird' for its absent mate, and the keen distress of a hen on losing her chickens, furnish abundant evidence of vivid feelings of the kind in question. Even the stupid-looking ostrich has heart enough to die for love, as was the case with a male in the Rotund of the Jardin des Plantes in Paris, who, having lost his wife, pined rapidly away. It is remarkable that in some species--notably pigeons--conjugal fidelity should be so strongly marked; for this shows, not only what may be called a refinement of sexual feeling, but also the presence of an abiding image in the mind's eye of the lover. For instance,--
Referring to the habits of the mandarin duck (a Chinese species) Mr. Bennett says that Mr. Beale's aviary afforded a singular corroboration of the fidelity of the birds in question. Of a pair in that gentleman's possession, the drake being one night purloined by some thieves, the unfortunate duck displayed the strongest marks of despair at her bereavement, retiring into a corner, and altogether neglecting food and drink, as well as the care of her person. In this condition she was courted by a drake who had lost his mate, but who met with no encouragement from the widow. On the stolen drake being subsequently recovered and restored to the aviary, the most extravagant demonstrations of joy were displayed by the fond couple; but this was not all, for, as if informed by his spouse of the gallant proposals made to her shortly before his arrival, the drake attacked the luckless bird who would have supplanted him, beat out his eyes, and inflicted so many injuries as to cause his death.
Similarly, to give an instance or two with regard to other birds, Jesse states the following as his own observation:--
A pair of swans had been inseparable companions for three years, during which time they had reared three broods of cygnets; last autumn the male was killed, and since that time the female has separated herself from all society with her own species; and, though at the time I am writing (the end of March) the breeding season for swans has far advanced, she remains in the same state of seclusion, resisting the addresses of a male swan, who has been making advances towards forming an acquaintance with her, either driving him away, or flying from him whenever he comes near her. How long she will continue in this state of widowhood I know not, but at present it is quite evident that she has not forgotten her former partner.
This reminds me of a circumstance which lately happened at Chalk Farm, near Hampton. A man, set to watch a field of peas which had been much preyed upon by pigeons, shot an old cock pigeon which had long been an inhabitant of the farm. His mate, around whom he had for many a year cooed, whom he had nourished from his own crop, and had assisted in rearing numerous young ones, immediately settled on the ground by his side, and showed her grief in the most expressive manner. The labourer took up the dead bird, and tied it to a short stake, thinking that it would frighten away the other depredators. In this situation, however, the widow did not forsake her deceased husband, but continued, day after day, walking slowly round the stick. The kind-hearted wife of the bailiff of the farm at last heard of the circumstance, and immediately went to afford what relief she could to the poor bird. She told me that, on arriving at the spot, she found the hen bird much exhausted, and that she had made a circular beaten track round the dead pigeon, making now and then a little spring towards him. On the removal of the dead bird the hen returned to the dove-cote.
As evidence of the intensity of the maternal instinct even in the case of barren birds, I may quote the following from the naturalist Couch. I do so because, although the instance is a trivial one, and also one of frequent occurrence, it is interesting as showing that a deeply rooted instinct or emotion may assert itself powerfully even in the absence of what may be termed its natural stimulus or object:--
I was once witness to a curious instance of the yearning for progeny in a diminutive bantam hen.
There was at this time a nest of the common hen in a secluded part of the garden, and the parent had been sitting on its eggs, till compelled by hunger she left them for a short time. This absence was fatal; for the bantam had in the meantime found its situation in a covered recess in the hedge, and I saw her creep into it with all the triumph of the discoverer of a treasure. The real mother now returned, and great was her agony at finding an intruder in her nest. The expression of her eye and the attitude of her head were emphatic of surprise at the impudence of the proceeding. But after many attempts to recover possession she was compelled to resign her rights, for the bantam was too resolute to be contended with; and though its body was not big enough to cover the whole of the eggs, and thus some of them were not hatched, yet in due season the pride of this audacious step-mother was gratified by strutting at the head of a company of robust chickens, which she passed off upon the feathered public as a brood of her own.
As evidence of sympathy I shall quote in extenso an interesting case which has been communicated to me by a young lady, who desires her name withheld. There are several more or less corroborative cases in the anecdote-books, so that I have no doubt as to the substantial accuracy of the account:--
My grandfather had a Swan River gander, which had been reared near the house, and had consequently attached himself to the members of the family; so much so that, on seeing any of them at a distance, he would run to meet them with all possible demonstrations of delight.
But 'Swanny' was quite an outcast from his own tribe; and as often as he made humble overtures to the other geese, so often was he driven away with great contempt, and on such occasions he would frequently run to some of his human friends, and laying his head on their laps, seem to seek for sympathy. At last, however, he found a friend among his own species. An old grey goose, becoming blind, was also discarded by her more fortunate companions, and Swanny lost no opportunity of recognising this comrade in distress. He at once took her under his protection and led her about. When he considered it well for her to have a swim, he would gently take her neck in his bill, and thus lead her, sometimes a considerable distance, to the water's edge. Having fairly launched her, he kept close by her side, and guided her from dangerous places by arching his neck over hers, and so turning her in the right direction. After cruising about a sufficient time, he would guide her to a convenient landing-place, and taking her neck in his bill as before, lead her to terra firma again. When she had goslings, he would proudly convoy the whole party to the water-side; and if any ill-fated gosling got into difficulties in a hole or deep cart-rut, Swanny with ready skill would put his bill under its body, and carefully raise it to the level ground.
My grandfather had also another gander who attached himself to him, and would follow him for hours through fields and lanes, pausing when he stood still, and waddling gravely by his side as he proceeded. This gander was not, like the other, discarded by his kind, but would leave them any time to walk with his master, and was exceedingly jealous of any one else who tried to share this privilege, excepting only his mistress. On one occasion, a gentleman venturing to place his hand on my grandfather's arm, the gander flew at him, and beat him severely with his wings, and it was with great difficulty that he was induced to let go.
The solicitude which most gregarious birds display when one of their number is wounded or captured, constitutes strong evidence of sympathy. As Jesse observes,--
There is one trait in the character of the rook which is, I believe, peculiar to that bird, and which does him no little credit; it is the distress which is exhibited when one of his fellows has been killed or wounded by a gun while they have been feeding in a field or flying over it. Instead of being scared away by the report of the gun, leaving their wounded or dead companion to his fate, they show the greatest anxiety and sympathy for him, uttering cries of distress, and plainly proving that they wish to render him assistance by hovering over him, or sometimes making a dart from the air close up to him, apparently to try and find out the reason why he did not follow them. . . . I have seen one of my labourers pick up a rook which he had shot at for the purpose of putting him up as a scarecrow in a field of wheat, and while the poor wounded bird was still fluttering in his hand, I have observed one of his companions make a wheel round in the air, and suddenly dart past him so as almost to touch him, perhaps with the last hope that he might still afford assistance to his unfortunate mate or companion. Even when the dead bird has been hung, in terrorem, to a stake in the field, he has been visited by some of his former friends, but as soon as they found that the case was hopeless, they have generally abandoned that field altogether.
When one considers the instinctive care with which rooks avoid any one carrying a gun, and which is so evident that I have often heard country people remark that a rook can smell gunpowder, one can more justly estimate the force of their love or friendship in thus continuing to hover round a person who has just destroyed one of their companions with an instrument the dangerous nature of which they seem fully capable of appreciating.
The justice of these remarks may be better appreciated in the light of the following very remarkable observation, as an introduction to which I have quoted them.
Edward, the naturalist, having shot a tern, which fell winged into the sea, its companions hovered around the floating bird, manifesting much apparent solicitude, as terns and gulls always do under such circumstances. How far this apparent solicitude is real I have often speculated, as in the analogous case of the crows--wondering whether the emotions concerned were really those of sympathy or mere curiosity. The following observation, however, seems to set this question at rest. Having begun to make preparations for securing the wounded bird, Edward says: 'I expected in a few moments to have it in my possession, being not very far from the water's edge, and drifting shorewards with the wind.' He continues:--
While matters were in this position I beheld, to my utter astonishment and surprise, two of the unwounded terns take hold of their disabled comrade, one at each wing, lift him out of the water, and bear him out seawards. They were followed by two other birds. After being carried about six or seven yards, he was let gently down again, when he was taken up in a similar manner by the two who had been hitherto inactive. In this way they continued to carry him alternately, until they had conveyed him to a rock at a considerable distance, upon which they landed him in safety. Having recovered my self-possession, I made toward the rock, wishing to obtain the prize which had been so unceremoniously snatched from my grasp. I was observed, however, by the terns; and instead of four, I had in a short time a whole swarm about me. On my near approach to the rock I once more beheld two of them take hold of the wounded bird as they had done already, and bear him out to sea in triumph, far beyond my reach. This, had I been so inclined, I could no doubt have prevented. Under the circumstances, however, my feelings would not permit me; and I willingly allowed them to perform without molestation an act of mercy, and to exhibit an instance of affection which man himself need not be ashamed to imitate.
According to Clavigero, the inhabitants of Mexico utilise the sympathy of the wild pelican for the procuring of fish. First a pelican is caught and its wing broken. The bird is then tied to a tree, and being both in pain and captivity, it utters cries of distress. Other pelicans are attracted by the cries, and finding their friend in such a sorry case, their bowels of compassion become moved in a very literal sense; for they disgorge from their stomachs and pouches the fish which they have caught, and deposit them within reach of the captive. As soon as this is done the men, who have been lying in wait concealed, run to the spot, drive off the friendly pelicans, and secure their fish, leaving only a small quantity for the use of the captive.
The parrot which belonged to the Buffon family showed much sympathy with a female servant to whom it was attached when the girl had a sore finger, which it displayed by its never leaving her sick room, and groaning as if itself in pain. As soon as the girl got better the bird again became cheerful.
I shall conclude this brief demonstration of the keen sympathy which may exist in birds, by quoting the following very conclusive case in the words of its distinguished observer, Dr. Franklin:--
I have known two parrots, said he, which had lived together four years, when the female became weak, and her legs swelled. These were symptoms of gout, a disease to which all birds of this family are very subject in England. It became impossible for her to descend from the perch, or to take her food as formerly, but the male was most assiduous in carrying it to her in his beak. He continued feeding her in this manner during four months, but the infirmities of his companion increased from day to day, so that at last she was unable to support herself on the perch. She remained cowering down in the bottom of the cage, making, from time to time, ineffectual efforts to regain the perch. The male was always near her, and with all his strength aided the feeble attempts of his dear better half. Seizing the poor invalid by the beak, or the upper part of the wing, he tried to raise her, and renewed his efforts several times.
His constancy, his gestures, and his continued solicitude, all showed in this affectionate bird the most ardent desire to relieve the sufferings and assist the weakness of his companion.
But the scene became still more interesting when the female was dying. Her unhappy spouse moved around her incessantly, his attention and tender cares redoubled. He even tried to open her beak to give some nourishment. He ran to her, then returned with a troubled and agitated look. At intervals he uttered the most plaintive cries; then, with his eyes fixed on her, kept a mournful silence. At length his companion breathed her last; from that moment he pined away, and died in the course of a few weeks.
The jealousy of birds is proverbial; and that they also manifest the kindred passion of emulation, no one can doubt who has heard them singing against one another. Mr. Bold relates that a mule canary would always sing at his own image in a mirror, becoming more and more excited, till he ended by flying in rage against his supposed rival.
The late Lady Napier wrote me, among other 'anecdotes of a grey parrot left on a long visit to the family of General Sir William Napier, at the time residing in Germany,' the following graphic description of the exultation displayed by the bird when it baffled the imitative powers of its master. The bird was the same as that already mentioned under the head of 'Memory':--
Sometimes when only two or three were in the room, at quiet occupations instead of talking, she would utter at short intervals a series of strong squalls or cries in an interjectional style, each more strange and grotesque than the previous one. My father on these occasions sometimes amused himself by imitating these cries as she uttered them, which seemed to excite her ingenuity in the production of them to the uttermost. As a last resource she always had recourse to a very peculiar one, which completely baffled him; upon which, with a loud ha! ha! ha! she made a somersault round her perch, swinging with her head downwards, sprung from one part of the cage to another, and tossed a bit of wood she used as a toy over her head in the most exulting triumph, repeating at intervals the inimitable cry, followed by peals of ha! ha! ha! to the great amusement of all present.
Allied to emulation is resentment, of which the following, communicated to me by a correspondent, may be taken as an example. If space permitted I could give confirmatory cases:--
One day the cat and the parrot had a quarrel. I think the cat had upset Polly's food, or something of that kind; however, they seemed all right again. An hour or so after, Polly was standing on the edge of the table; she called out in a tone of extreme affection, 'Puss, puss, come then--come then, pussy.' Pussy went and looked up innocently enough. Polly with her beak seized a basin of milk standing by, and tipped the basin and all its contents over the cat; then chuckled diabolically, of course broke the basin, and half drowned the cat.
Several strange but mutually corroborative stories seem to show cherished vindictiveness on the part of storks. Thus, in Captain Brown's book there occurs an account of a tame stork which lived in the college yard at Tübingen,--
And in a neighbouring house was a nest, in which other storks, that annually resorted to the place, used to hatch their eggs. At this nest, one day in autumn, a young collegian fired a shot, by which the stork that was sitting on it was probably wounded, for it did not fly out of the nest for some weeks afterwards. It was able, however, to take its departure at the usual time with the rest of the storks. But in the ensuing spring a strange stork was observed on the roof of the college, which, by clapping his wings and other gestures, seemed to invite the tame stork to come to him; but, as the tame one's wings were clipped, he was unable to accept the invitation. After some days the strange stork appeared again, and came down into the yard, when the tame one went out to meet him, clapping his wings as if to bid him welcome, but was suddenly attacked by the visitor with great fury. Some of the neighbours protected the tame bird, and drove off the assailant, but he returned several times afterwards, and incommoded the other through the whole summer. The next spring, instead of one stork only, four storks came together into the yard, and fell upon the tame one; when all the poultry present--cocks, hens, geese, and ducks--flocked at once to his assistance, and rescued him from his enemies. In consequence of this serious attack, the people of the house took precaution for the tame stork's security, and he was no more molested that year. But in the beginning of the third spring came upwards of twenty storks, which rushed at once into the yard and killed the tame stork before either man or any other animal could afford him protection.
A similar occurrence took place on the premises of a farmer near Hamburg, who kept a tame stork, and, having caught another, thought to make it a companion for the one in his possession. But the two were no sooner brought together than the tame one fell upon the other, and beat him so severely that he made his escape from the place. About four months afterwards, however, the defeated stork returned with three others, who all made a combined attack upon the tame one and killed him.
The curiosity of birds is highly developed, so much so, indeed, that in this and other countries it is played upon by sportsmen and trappers. Unfamiliar objects being placed within sight, say, of ducks, the birds approach to examine them, and fall into the snares which have been prepared. Similarly, in oceanic islands unfrequented by man, the birds fearlessly approach to examine the first human beings that they have seen.
That birds exhibit pride might be considered doubtful if we had to rely only on the evidence supplied by the display of the peacock, and the strutting of the turkey-gobbler; for these actions, although so expressive of this emotion, may not really be due to it. But I think that the evident pleasure which is taken in achievement by talking birds can only be ascribed to the emotion in question. These birds regularly practise their art, and when a new phrase is perfected they show an unmistakable delight in displaying the result.
Play is exhibited by many species in various ways, and it seems to be this class of feelings in their most organised form which have led to the extraordinary instincts of the bower-birds of New South Wales. The 'playhouses' of the animals have been described by Mr. Gould in his 'History of the Birds of New South Wales.' Of course the play-instincts are here united with those of courtship, which are of such general occurrence among birds; but I think no one can read Mr. Gould's description of the bowers and the uses to which they are put without feeling that the love of sportive play must have been joined with the sexual instincts in producing the result. But, be this as it may, there can be no question that these bowers are highly interesting structures, as furnishing the most unexceptionable evidence of true æsthetic, if not artistic feeling, on the part of the bird which constructs them; and, according to Mr. Herbert Spencer, the artistic feelings are physiologically allied with those of play. It is a matter of importance to obtain definite proof of an æsthetic sense in animals, because this constitutes the basis of Mr. Darwin's theory of sexual selection; but as he has treated the evidence on this subject in so exhaustive a manner, I shall not enter upon so wide a field further than to point out that the case of the bower-bird, even if it stood alone, would be amply sufficient to carry the general conclusion that some animals exhibit emotions of the beautiful. The following is Mr. Gould's description, in extenso, of the habits of the bird in question:--
The extraordinary bower-like structure, alluded to in my remarks on the genus, first came under my notice in the Sydney Museum, to which an example had been presented by Charles Cox, Esq. . . . On visiting the cedar bushes of the Liverpool range, I discovered several of these bowers or playing-houses on the ground, under the shelter of the branches of the overhanging trees, in the most retired part of the forest; they differed considerably in size, some being a third larger than others. The base consists of an extensive and rather convex platform of sticks firmly interwoven, on the centre of which the bower itself is built. This, like the platform on which it is placed, and with which it is interwoven, is formed of sticks and twigs, but of a more slender and flexible description, the tips of the twigs being so arranged as to curve inwards and nearly meet at the top; in the interior the materials are so placed that the forks of the twigs are always presented outwards, by which arrangement not the slightest obstruction is offered to the passage of the birds. The interest of this curious bower is much enhanced by the manner in which it is decorated with the most gaily coloured articles that can be collected, such as the blue tail-feathers of the Rose-hill and Pennantian parakeets, bleached bones and shells of snails, &c.; some of the feathers are inserted among the twigs, while others with the bones and shells are strewed near the entrances. The propensity of these birds to fly off with any attractive object is so well known to the natives that they always search the runs for any small missing article that may have been accidentally dropped in the bush. I myself found at the entrance of one of them a small neatly worked stone tomahawk of an inch and a half in length, together with some slips of blue cotton rag, which the birds had doubtless picked up at a deserted encampment of the natives.
It has now been clearly ascertained that these curious bowers are merely sporting-places in which the sexes meet, when the males display their finery, and exhibit many remarkable actions; and so inherent is this habit, that the living examples, which have been from time to time sent to this country, continue it even in captivity. Those belonging to the Zoological Society have constructed their bowers, decorated and kept them in repair, for several years. In a letter from the late Mr. F. Strange, it is said:--
My aviary is now tenanted by a pair of satin-birds, which for the last two months have been constantly engaged in constructing bowers. Both sexes assist in their erection, but the male is the principal workman. At times the male will chase the female all over the aviary, then go to the bower, pick up a gay feather or a large leaf, utter a curious kind of note, set all his feathers erect, run round the bower, and become so excited that his eyes appear ready to start from his head, and he continues opening first one wing and then another, uttering a low whistling note, and, like the domestic cock, seems to be picking up something from the ground, until at last the female goes gently towards him, when after two turns round her, he suddenly makes a dash, and the scene ends.
I have said that if this case stood alone it would constitute ample evidence that some animals possess emotions of the beautiful. But the case does not stand alone. Certain humming-birds, according to Mr. Gould, decorate the outsides of their nests 'with the utmost taste; they instinctively fasten thereon beautiful pieces of flat lichen, the larger pieces in the middle, and the smaller on the part attached to the branch. Now and then a pretty feather is intertwined or fastened to the outer sides, the stem being always so placed that the feather stands out beyond the surface.' Several other instances might be rendered of the display of artistic feeling in the architecture of birds; and, as Mr. Darwin so elaborately shows, there can scarcely be question that these animals take emotional pleasure in surveying beautiful plumage in the opposite sex, looking to the careful manner in which the males of many species display their fine colours to the females. Doubtless the evidence of æsthetic feeling is much stronger in the case of birds than it is in that of any other class; but if this feeling is accepted as a sufficient cause, through sexual selection, of natural decoration in the members of this class, we are justified in attributing to sexual selection, and so to æsthetic feeling, natural decoration in other classes, at least as low down in the scale as the Articulata. But, as I have said, Mr. Darwin has dealt with this whole subject in so exhaustive a manner that it is needless for me to enter upon it further than to say in general terms, that whatever we may think of his theory of sexual selection, his researches have unquestionably proved the existence of an æsthetic sense in animals.
The same fact appears to be shown in another way by the fondness of song-birds for the music of their mates. There can be no doubt that male birds charm their females with their strains, and that this, in fact, is the reason why song in birds has become developed. Of course it may be said that the vocal utterances of birds are not always, or even generally, musical; but this does not affect the fact that birds find some æsthetic pleasure in the sounds which they emit; it only shows that the standard of æsthetic taste differs in different species of birds as it does in different races of men. Moreover, the pleasure which birds manifest in musical sounds is not always restricted to the sounds which they themselves produce. Parrots seem certainly to take delight in hearing a piano play or a girl sing; and the following instance, published by the musician John Lockman, reveals in a remarkable manner the power of distinguishing a particular air, and of preferring it above others. He was staying at the house of a Mr. Lee in Cheshire, whose daughter used to play; and whenever she played the air of 'Speri si' from Handel's opera of 'Admetus,' a pigeon would descend from an adjacent dovecot to the window of the room where she sat, 'and listen to the air apparently with the most pleasing emotions,' always returning to the dovecot immediately the air was finished. But it was only this one air that would induce the bird to behave in this way.
Special Habits._
Under this heading we shall have a number of facts to consider, which are more or less of a disconnected character.
Taking first those special habits connected with the procuring of food, we may notice the instinct manifested by blackbirds and thrushes of conveying snails to considerable distances in order to hammer and break their shells against what may happen to be the nearest stone, and the still more clever though somewhat analogous instinct exhibited by certain gulls and crows of flying with shell-fish to a considerable height and letting them fall upon stones for the purpose of smashing their shells. Both these instincts manifest a high degree of intelligence, either on the part of the birds themselves, or on that of their ancestors; for neither of these instincts can be regarded as due to originally accidental adjustments favoured and improved by natural selection; they must at least originally have been intelligent actions purposely designed to secure the ends attained.
An interesting instinct is that of piracy, which in the animal kingdom reaches its highest or most systematic development among the birds. It is easy to see how it may be of more advantage to a species of strong bird that its members should become parasitic on the labours of other species than that they should forage for themselves, and so there is no difficulty in understanding the development of the plundering instinct by natural selection. We find all stages of this development among the sea-birds. Thus the gulls, although usually self-foragers, will, as I have often observed, congregate in enormous numbers where the guillemots have found a shoal of fish. Resting on or flying over the surface of the water, the gulls wait till a guillemot comes to the surface with a fish, and then wrest the latter from the beak of the former. In the robber-tern this instinct has proceeded further, so that the animal gains its subsistence entirely by plunder of other terns. I have often observed this process, and it is interesting that the common tern well knows the appearance of the robber; for no sooner does a robber-tern come up than the greatest consternation is excited among a flock of common terns, these flying about and screaming in a frantic manner. The white-headed eagle has also developed the plundering instinct in great perfection, as is shown by the following graphic account of Audubon:--
During spring and summer, the white-headed eagle, to procure sustenance, follows a different course, and one much less suited to a bird apparently so well able to supply itself without interfering with other plunderers. No sooner does the first hawk make its appearance along the Atlantic shore, or around the numerous and large rivers, than the eagle follows it, and, like a selfish oppressor, robs it of the hard-earned fruits of its labour. Perched on some tall summit, in view of the ocean or of some watercourse, he watches every motion of the osprey while on the wing. When the latter rises from the water, with a fish in its grasp, forth rushes the eagle in pursuit. He mounts above the fish-hawk, and threatens it by actions well understood; when the latter, fearing perhaps that its life is in danger, drops its prey. In an instant the eagle, accurately estimating the rapid descent of the fish, closes its wings, follows it with the swiftness of thought, and the next moment grasps it. The prize is carried off in silence to the woods, and assists in feeding the ever-hungry brood of the eagle.
The frigate pelican is likewise a professional thief, and attacks the boobies not only to make them drop the fish which they have newly caught, but also to disgorge those which are actually in their stomachs. The latter process is effected by strong punishment, which they continue until the unfortunate booby yields up its dinner. The punishment consists in stabbing the victim with its powerful beak. Catesby and Dampier have both observed and described these habits, and it seems from their account that the plunderer may either commit highway robbery in the air, or lie in wait for the boobies as they return to rest.
In antithesis to this habit of plundering other birds I may quote the following from 'Nature' (July 20, 1871), to show that the instinct of provident labour, so common among insects and rodents, is not altogether unrepresented in birds:--
The ant-eating woodpecker (Melanerpes formicivorus), a common Californian species, has the curious and peculiar habit of laying up provision against the inclement season. Small round holes are dug in the bark of the pine and oak, into each of which is inserted an acorn, and so tightly is it fitted or driven in, that it is with difficulty extricated. The bark of the pine trees, when thus filled, presents at a short distance the appearance of being studded with nails.
The following may also be quoted:--
It is the nature of this bird (guillemot), as well as of most of those birds which habitually dive to take their prey, to perform all their evolutions under water with the aid of their wings; but instead of dashing at once into the midst of the terrified group of small prey, by which only a few would be captured, it passes round and round them, and so drives them into a heap; and thus has an opportunity of snatching here one and there another as it finds it convenient to swallow them; and if any one pushes out to escape, it falls the first prey of the devourer. The manner in which this bird removes the egg of a gull or hen to some secure place to be devoured, when compared with that in which a like conveyance is made by the parent for the safety of its future progeny, affords a striking manifestation of the difference between appetite and affection. When influenced by affection, the brittle treasure is removed without flaw or fracture, and is replaced with tender care; but the plunderer at once plunges his bill into its substance, and carries it off on its point.
Speaking of the feeding habits of the lapwing, Jesse says:--
When the lapwing wants to procure food, it seeks for a worm's cast, and stamps the ground by the side of it with its feet. After doing this for a short time, the bird waits for the issue of the worm from its hole, which, alarmed at the shaking of the ground, endeavours to make its escape, when it is immediately seized, and becomes the prey of the ingenious bird. The lapwing also frequents the haunts of moles, which, when in pursuit of worms on which they feed, frighten them, and the worm, in attempting to escape, comes to the surface of the ground, when it is seized by the lapwing.
Again,--
A lady of Dr. E. Darwin's acquaintance saw a little bird repeatedly hop on a poppy stem, and shake the head with his bill, till many seeds were scattered, when it settled on the ground and picked up the seeds.
It is a matter of common remark that in countries where vultures abound, these birds rapidly 'gather together where the carcass is,' although before the death of their prey no bird was to be seen in the sky. The question has always been asked whether the vultures are guided to the carcass by their sense of smell or by that of sight; but this question is really no longer an open one. When Mr. Darwin was at Valparaiso he tried the following experiment. Having tied a number of condors in a long row, and having folded up a piece of meat in paper, he walked backwards and forwards in front of the row, carrying the meat at a distance of three yards from them, 'but no notice whatever was taken.' He then threw the meat upon the ground, within one yard of an old male bird; 'he looked at it for a moment with attention, but then regarded it no more.' With a stick he next pushed the meat right under the beak of the bird. Then for the first time the bird smelled it, and tore open the paper 'with fury, and at the same moment every bird in the long row began struggling and flapping its wings.' Thus there can be no doubt that vultures do not depend on their sense of smell for finding carrion at a distance. Nor is it mysterious why they should find it by their sense of sight. If over an area of many square miles there are a number of vultures flying as they do at a very high elevation, and if one of the number perceives a carcass and begins to descend, the next adjacent vultures would see the descent of the first one, and follow him as a guide, while the next in the series would follow these in the same way, and so on.
· · ·
End of part 19 of 33
Continue readingChapter 10: Birds (Part 2)
Starvard