Most species of birds like to roost in companies, partly because it is safer to do so, partly for the sake of companionship, and sometimes, in England at any rate, because by crowding together they keep each other warm. Birds have their favourite roosting places. Certain trees are patronised while others are not. Perhaps one clump will be utilised every night for a month or longer, then a move will be made to another clump. Later on a return may be made to the original site. I do not know what determines these changes of locality.
The sunset hour is, I think, the most interesting at which to watch birds. They seem to be livelier then than at any other time of the day; they are certainly more loquacious. The dormitory of the crows, the mynas, or the green parrots is a perfect pandemonium. Whilst listening to the uproar one can only suppose each member of the colony to be bubbling over with animal spirits and intent on recounting to his fellows all the doings of the day.
Most people may be inclined to think that it is impossible to derive much pleasure from observing so common a bird as the sparrow. This is a mistake. Often and often have I watched with the greatestpleasure the roosting operations of this despised bird. I know of a row of bushes that forms the dormitory of hundreds of sparrows. To enable the reader to appreciate what follows, let me say that the hedge in question is only some twenty yards long, its height is not much greater than that of a man, it is nowhere more than eight feet in breadth, and is within a hundred yards of an inhabited bungalow. Less than six yards away from it is a well, fitted with a creaking Persian wheel, at which coolies are continually working.
If you happen to pass this hedge within an hour of sunset, you will hear issuing from it the dissonance of many sparrows’ voices. You stop to listen, and, as you wait, a flock of sparrows dives into the thicket. You look about to see whether any more are coming and observe nothing. Suddenly some specks appear in the air, as if spontaneously generated. In two seconds these are seen to be sparrows. Within half a minute of the time you first set eyes upon them they are already in the bushes. They are followed by another little flock of six or seven, and another and another. Flight after flight arrives in quick succession, each of which shoots into the roosting hedge. I use the word “shoot” advisedly, for no other term describes the speed at which they enter the bushes. Their flight, although so rapid, is not direct; it takes the form of a quavering zigzag. Some of the flocks do not immediately plunge into the bushes. They circle once, twice, thrice, or even oftener, before they betake themselves to their leafy dormitory. Sometimes part of a flight dive into the hedge immediately upon arrival, while the remainder circle roundand then fling themselves into the bushes as though they were soldiers performing a well-practised manœuvre; the first bird to reach the bush entering at the nearest end, the next a little farther on, the third still farther, and so on, so that the last sparrow to arrive enters the hedge at the far end. Sometimes a flock perches for a time on a tree near by before entering the hedge. Those who have only noticed sparrows pottering about will scarcely be able to believe their eyes when they see the speed at which they approach the roosting place. For the moment they are transformed into dignified birds.
All this time those individuals already in the hedge are making a great noise. Their chitter, chitter, chitter never for a moment ceases or even diminishes in intensity. Once in the hedge, the sparrows do not readily leave it. There is much motion of the leaves and branches, and birds are continually popping out of one part of the bushes into another. It is thus evident that there is considerable fighting for places. If, while all this is going on, you walk up to part of the hedge and shake it, the birds disturbed will only fly a yard or two and at once settle elsewhere in the thicket.
Meanwhile the sun has nearly set; the coolies near by have ceased working and are kindling a fire within a couple of yards of the bushes. But the sparrows appear to ignore both them and their fire. Settling down for the night engrosses their whole attention.
As the sun touches the horizon the incoming flights of sparrows become fewer and fewer; and after the golden orb has disappeared only one or two belated stragglersarrive. Sparrows are early roosters. Something approaching three thousand of them are now perched in that small hedge, yet none are visible except those that pop in and out, when jockeyed out of positions they have taken up. But although only a few sparrows come in after the sun has set, it is not until fully fifteen minutes later that there is any appreciable abatement of the din. It then becomes more spasmodic; it ceases for half a second, to burst forth again with undiminished intensity.
Twenty minutes or so after sunset the clamour becomes suddenly less. It is now possible to discern individual voices. The noise grows rapidly feebler. It almost ceases, but again becomes louder. It then nearly stops a second time. Perhaps not more than twenty voices are heard. There is yet another outburst, but the twitterers are by now very sleepy. Suddenly there is perfect silence for a few seconds, then more feeble twittering, then another silence longer than the last.
It is not yet dark, there is still a bright glow in the western sky. The periods of silence grow more prolonged and the outbursts of twittering become more faint and of shorter duration.
It is now thirty-nine minutes after the sun has set and perfect stillness reigns. The birds must have all fallen asleep. But no! one wakeful fellow commences again. He soon subsides. It has grown so dark that you can no longer see the sparrow-hawk perched on a tree hard by. He took up his position there early in the evening, and will probably breakfast first thing to-morrow morning off sparrow!
You now softly approach the bushes until your facetouches the branches. There are twenty or thirty sparrows roosting within fifteen inches of you. You cannot see any of them, but if you were to stretch forth your hand you could as likely as not catch hold of one. You disturb a branch and there is a rustling of a dozen pairs of wings, so close to you that your face is fanned by the wind they cause. You have disturbed some birds, but they are so sleepy that they move without uttering a twitter. You leave the bush and return an hour later. Perfect silence reigns. You may now go right up to the roosting hedge and talk without disturbing any of the three thousand birds. You may even strike a match without arousing one, so soundly do they sleep.
Those who wish to rid a locality of a superabundance of sparrows might well profit by the fact that the birds sleep so soundly in companies. Could anything be easier than to throw a large net over such a hedge and thus secure, at one fell blow, the whole colony?
The drongo cuckoo (Surniculus lugubris) is a bird of which I know practically nothing. I doubt whether I have ever seen it in the flesh. It is, of course, quite unnecessary to apologise for discoursing upon a subject of which one’s knowledge is admittedlynil. In this superficial age the most successful writers are those most ignorant of their subject. When you know only one or two facts it is quite easy to parade them properly, to set them forth to best advantage. They are so few and far between that there is no danger of their jostling one another or bewildering the reader. Then, if you are conversant only with one side of a question, you are able to lay down the law so forcibly, and the public likes having the law laid down for it, it does not mind how crude, how absurd, how impossible one’s sentiments are so long as one is cocksure of them and is not afraid to say so.
My lack of knowledge of the habits of the drongo cuckoo is, however, not my chief reason for desiring to write about it. I wish to discuss the bird because natural selectionists frequently cite it as bearing striking testimony to the truth of their theory, whereas it seems to me that it does just the opposite.Surniculus lugubrisis, so far as I am able to judge, an uncompromisingopponent of those zoologists who pin their faith to the all-sufficiency of natural selection to account for evolution in the organic world.
The drongo cuckoo is as like the king-crow as one pea is to another. This bird, says Blanford, “is remarkable for its extraordinary resemblance in structure and colourisation to a drongo or king-crow (Dicrurus). The plumage is almost entirely black, and the tail forked owing to the lateral rectrices being turned outwards.” Blanford further declares that the bird, owing to its remarkable likeness to the king-crow, is apt to be overlooked.
This being so, it is quite unnecessary for me to describe the drongo cuckoo; it is the image of a king-crow. But stay, perhaps there are some who do not know this last bird by sight. Such should make its acquaintance. They will find it sitting on the next telegraph wire they pass—a sprightly black bird, much smaller than the crow (with which it has no connection), possessing a long, forked tail. Every now and again it makes little sallies into the air after the “circling gnat,” or anything else insectivorous that presents itself. When you see such a bird you may safely bet on its being a king-crow; the off-chance of its proving a drongo cuckoo may be neglected by all but the ultra-cautious.
Not much is known of the habits of this cuckoo; but what we do know shows that, sometimes, at any rate, it makes the king-crow act as its nursemaid. Mr. Davison saw two king-crows feeding a youngSurniculus. The consequence is that every book on natural history trotsout our friend the drongo cuckoo as an example of mimicry. The mimicry is, of course, unconscious: it is said to be the result of the action of natural selection.
King-crows are, as every one knows, exceedingly pugnacious birds; at the nesting season both cock and hen are little furies, who guard the nursery most carefully and will not allow a strange species to so much as perch in the tree in which it is placed.
It is thus obvious that the cuckoo who elects to victimise a king-crow is undertaking a “big thing,” yet this is whatSurniculusdoes. It accomplishes its aim by trickery; it becomes a gay deceiver, disguising itself like its dupe. Now I readily admit that the disguise may be of the utmost use to theSurniculus; I can well understand that natural selection will seize hold of the disguise when once it has been donned and possibly perfect it; but I cannot see how natural selection can have originated the disguiseas such.
The drongo cuckoo may be called an ass in a lion’s skin, or a lion in an ass’s skin, whichever way one looks at things. When once the skin has been assumed natural selection may modify it so as better to fit the wearer; but more than this it cannot do.
I do not pretend to know the colour of the last common ancestor of all the cuckoos, but I do not believe that the colour was black. What, then, causedSurniculus lugubristo become black and assume a king-crow-like tail?
A black feather or two, even if coupled with some lengthening of the tail, would in no way assist thecuckoo in placing its egg in the drongo’s nest. Suppose an ass were to borrow the caudal appendage of the king of the forest, pin it on behind him, and then advance among his fellows with loud brays, would any donkey of average intelligence be misled by the feeble attempt at disguise? I think not. Much less would a king-crow be deceived by a few black feathers in the plumage of a cuckoo.
I do not believe that natural selection has any direct connection with the nigritude of the drongo cuckoo. It is my opinion that, so far as the struggle for existence is concerned, it matters little to an animal what its colour be. Every creature has to be some colour: what that actual colour is must depend upon a great many factors; among these we may name the metabolic changes that go on inside the animal, its hereditary tendencies, sexual selection, and natural selection. Is it natural selection that has caused the king-crow to be black? I trow not.
The drongo is black because it is built that way; its tendency is to produce black feathers. Just as some men tend to put on flesh, so also some species of birds tend to grow black plumage. In the case of the king-crow sexual selection has possibly contributed to the bird’s nigritude. It is possible that black is a colour that appeals to king-crow ladies. “So neat, you know; a bird always looks well in black, and a forked tail gives him such an air of distinction.”
As the hen drongo is a bird capable of looking after herself, even when incubating, there is no necessity for her to be protectively coloured. As I have repeatedlydeclared, one ounce of good solid pugnacity is a better weapon in the struggle for existence than many pounds of protective colouration.
Again, in the case of king-crows nigritude may be an expression of vigour, the outward and visible sign of strength.
Let me make myself clear. Suppose that in a race of savages those that had fair hair were stronger, bolder, more prolific, and more pushing than the dark-haired men. Fair hair, in some inexplicable way, always accompanied strength and the like. It is obvious that, under these conditions, the race would in time become fair-haired: the milder dark men would eventually be hustled out of existence. Fair hair would then be the outward expression of vigour: it would not be the cause of vigour, merely the accompaniment of it; nor would it be a direct product of natural selection. In the same way it is possible that among drongos nigritude is in some manner correlated with vigour. This idea is not altogether fanciful. Are there not horses of “bad colour”? Are not white “socks” a sign of weakness? Is not roan a colour indicative of strength and endurance in a horse?
May not the blackness and the forked tail of the drongo cuckoo have arisen in the same way as they arose in the king-crow? In each case it may be an accompaniment of vigour, or it may be the result of sexual selection. Mrs. Surniculus may have had similar tastes to Mrs. Dicrurus, and, since cuckoos seem to be very plastic birds, her tastes have been gratified. As another example of this plasticity I may citeCentropus phasianus—a cuckoo which is a very fair imitation of a pheasant.
On this view the resemblance is a mere chance one. The cuckoo is not an ass in a lion’s skin, but an ass that looks very like a lion. His lion-like shape was not forced upon him by natural selection. A variety of causes probably contributed to it. It was not until the resemblance had arisen and become very striking that it was directly affected by natural selection.
I am far from saying that the above is a correct explanation of the nigritude: it is all pure hypothesis. Even if it be correct, we are really very little further than we were before towards an explanation of the colours and shape of either the king-crow or the drongo cuckoo.
Why did these birds tend to grow black feathers rather than red, green, or blue ones?
This is a question which “stumps” us all.
If I have a favourite bird it is the little green bee-eater (Merops viridis). There is no winged thing more beautiful or more alluring. More showy birds exist, more striking, more gorgeous, more magnificent creatures. With such the bee-eater does not compete. Its beauty is of another order. It is that of the moon rather than of the sun, of the violet rather than of the rose. The exquisite shades of its plumage cannot be fully appreciated unless minutely inspected. Every feather is a triumph of colouring. No description can do the bird justice. To say that its general hue is the fresh, soft green of grass in England after an April shower, that the head is covered with burnished gold, that the tail is tinted with olive, that a black collarette adorns the breast, that the bill is black, that a streak of that colour runs from the base of the beak, backwards, through the eye, which is fiery red, that the feathers below this streak are of the purest turquoise-blue, as are the feathers of the throat—to say all this is to convey no idea of the hundred shades of these colours, or the manner in which they harmonise and pass one into another. Nor is it easy for words to do justice to the shape of the bird; even a photograph fails to express the eleganceof its carriage and the perfection of its proportions. Were I to string together all the superlatives that I know, I should scarcely convey an adequate impression of the grace of its movements. I can but try to make the bird recognisable, so that the reader may see its beauties for himself.
He should look out for a little green bird with a black beak, slender and curved, and a tail of which the two middle feathers are very attenuated and project a couple of inches as two black bristles beyond the other caudal feathers. The bird should be looked for on a telegraph wire or the bare branch of a tree, for the habits of bee-eaters are those of fly-catchers. The larger species prey upon bees, hence the popular name, but I doubt whether the littleMerops viridistackles an insect so large as a bee. It feeds upon smaller flying things, which it captures on the wing. As it rests on its perch its bright eyes are always on the look out for passing insects. When one comes into view, the bird sallies forth. Very beautiful is it as it sails on outstretched wings. The under surface of these is reddish bronze, so that their possessor seems to become alternately green and gold as the sun’s rays fall on the upper or lower surface of its pinions. Its long mandibles close upon its prey with a snap sufficiently loud to be audible from a distance of five or six yards. This one may frequently hear, for bee-eaters are not shy birds. They will permit a human being to approach quite near to them, as though they knew that the fulness of their beauty was apparent only on close inspection.
The little green bee-eater utters what Jerdon calls “a rather pleasant rolling whistling note,” which, if it cannot be dignified by the name of song, adds considerably to the general attractiveness of the bird. Bee-eaters are, alas! not very abundant in Madras, but, if looked for, may be seen on most days in winter. The Adyar Club grounds seem to be their favourite resort. When driving into the club at sunset I have often surprised a little company of them taking a dust bath in the middle of the road. The bath over, the little creatures take to their wings and enjoy a final flight before retiring for the night.
Bee-eaters are, I think, migratory birds. It is true that they are found all the year round in many parts of India, but such places appear to be the winter quarters of some individuals and the summer residences of others. There is an exodus of bee-eaters from Calcutta about March. A similar event occurs in Madras, although in the latter place the birds are seen all the year round, a few remaining to breed. In Lahore, on the other hand, the birds arrive in March, and, having reared their young, leave in September.
The nest is a circular hole excavated by the bird, usually in a sandbank, sometimes in a mud partition between two fields. I saw a nest in Lahore in one of the artificial bunkers on the golf links. Major C. T. Bingham states that in 1873, when the musketry instruction of his regiment was being carried on at Allahabad, he observed several nest holes of this species in the face of the butts. The birds seemed utterly regardless of the bullets that every now and thenburied themselves with a loud thud in the earth close beside them. Colonel Butler gives an account of a bee-eater nesting in an artificial mudbank, about a foot high, that marked the limits of the badminton court in the Artillery Mess compound at Deesa. One of the birds invariably sat upon the badminton net when people were not playing, and at other times on a tree close by, while its mate was sitting on the eggs. As I have already said, bee-eaters are not afflicted with shyness.
Very soon after their arrival at Lahore the birds begin their courtship. At this period they seem to spend the major portion of the day in executing circular flights in the air. They shoot forth from their perch and rapidly ascend by flapping their wings, then they sail for a little on outstretched pinions and thus return to the perch.
Courtship soon gives place to the more serious business of nest construction. When a suitable spot has been found, the birds at once begin excavating, digging away at the earth with pick-like bill and holding on to the wall of the bank by their sharp claws until the hole they are making becomes sufficiently deep to afford a foothold. As the excavation grows deeper the bird throws backwards with its feet the sand it has loosened with its beak, sending it in little clouds out of the mouth of the hole. While one bird is at work its mate perches close by and gives vent to its twittering note. After working for about two minutes the bird has a rest and its partner takes a turn at excavation. Thus the work proceeds apace. Bee-eaterslook spick and span, even when in the midst of this hard labour. The dry sand that envelops them, far from soiling their plumage, acts as a dust bath. When the hole, which is about two inches in diameter, has reached a length of some four feet, it is widened out into a circular chamber about twice the size of a cricket ball. In this three or four white eggs are laid. These have been well described as “little polished alabaster balls.” They are placed on the bare ground. Young bee-eaters lack the elongated bristle-like tail feathers of the adult birds. A very pleasing sight is that of a number of the youngsters sitting in a row on a telegraph wire receiving instruction in flying.
In conclusion, mention must be made of a near relative of the little bee-eater. I allude to the blue-tailed species (Merops philippinus), which also occurs in Madras. This is a larger and less beautiful edition of the green bee-eater. It is distinguishable by its size, the rusty colour of its throat, and its blue tail. It is usually found near water. He who shoots snipe in the paddy near Madras comes across numbers of these birds sitting on the low walls that divide up the fields. The habits of the blue-tailed bee-eater are those of its smaller cousin. Although its song is more powerful, it is a less attractive bird.
Mr. John Burroughs contributed some time ago toHarper’s Magazinean article bearing the above title. The leading American naturalist is so weighty an authority that I feel chary about controverting any statement made by him; but I cannot believe that he is right when he boldly asserts that animals never think at all. I agree with Mr. Burroughs when he says “we are apt to speak of the lower animals in terms that we apply to our own kind.” There is undoubtedly a general tendency to give animals credit for much greater intelligence, far more considerable powers of reasoning, than they actually possess; in short, to put an anthropomorphic interpretation on their actions.
But it seems to me that Mr. Burroughs rushes to the other extreme. To deny to animals the power of thought is surely as opposed to facts as to credit them with almost human powers of reasoning. Says Mr. Burroughs: “Animals act with a certain grade of intelligence in the presence of things, but they carry away no concepts of those things as a man does, because they have no language. How could a crow tell his fellows of some future event or of some experience of the day? How could he tell them this thing isdangerous save by his actions in the presence of those things? Or how tell of a newly found food supply save by flying eagerly to it?”
Even if we admit that a crow is not able to recount the experiences of the day to his companion, it does not follow that the crow does not remember them, or cannot picture them in his mind. With regard to the last question, I have frequently seen a crow, at the sight of some food thrown out to him, caw loudly, and his friends, on hearing his cry, at once fly to the food.
Of course it is open to any one to assert that, in this case, the crow that discovers the food does not consciously call its companions; at the sight of its food it instinctively caws, and its companions obey the caw instinctively, without knowing why they do so. No one, however, who watches crows for long can help believing that they think. The fact that they hang about the kitchen every day at the time the cook pitches out the leavings seems inconsistent with the theory that birds cannot think. The crows obtained food at this place yesterday and the day before at a certain hour, and the fact that they are all on the look out for food to-day shows, not only that they possess a good memory, but that they are endowed with a certain amount of reasoning power.
Many animals have very good memories. Now, in order that an animal may remember a thing it must think. Its thoughts are of course not clothed in language as human thoughts are, but they nevertheless exist as mental pictures.
According to Professor Thorndike, the psychic life ofan animal is “most like what we feel when our consciousness contains little thought about anything, when we feel the sense impressions in their first intention, so to speak, when we feel our own body and the impulses we give to it (or that outward objects give to it). Sometimes one gets this animal consciousness; while in swimming, for example. One feels the water, the sky, the birds above, but with no thoughts about them, or memories of how they looked at other times, or æsthetic judgments about their beauty. One feels no ‘ideas’ about what movements he will make, but feels himself make them, feels his body throughout. Self-consciousness dies away. The meanings and values and connections of things die away. One feels sense-impressions, has impulses, feels the movements he makes; that is all.”
This is probably a good description of the state of mind of a dog when he is basking in the sunlight; he is thinking of nothing. But he hears the shrill cry of a squirrel—this at once recalls to him the image of the little rodent and pastshikar. In a moment the dog is on the alert; he is now thinking of the squirrel, and his instinct and inclinations teach him to give chase to it. Or he hears a footstep; he recognises it as that of his master, sees that the latter is wearing atopi, and at once pictures up a run in the compound with his master. But his owner chains him up. The dog looks wistfully at his master’s retreating figure and pulls at his chain; it is surely absurd to say that the dog is not thinking. The picture of a scamper beside his master rises up before him, and he feels sad because he knowsthat the scamper is not likely to become afait accompli.
Again, you have been accustomed to throw a stick for your dog to run after and carry back to you. You are out walking accompanied by your dog; he espies a stick lying on the ground; at once images of previous enjoyable runs after the stick rise up in his mind; he picks up the stick and brings it to you, drops it at your feet and looks up at you. You pretend to take no notice. The dog then picks up the stick and rubs it against your legs. To believe that the dog while acting thus does not think, that he is merely obeying an inborn instinct, is surely a misinterpretation of facts. Animals have but limited reasoning powers, and their thoughts are not our thoughts, they are not clothed in language, they are merely mental pictures, called up either subjectively, as when a dog barks while dreaming, or objectively by some sight or scent, but nevertheless such sensations are thoughts.
While maintaining that the higher animals can and do think, I am ready to admit that a great many of their actions which are apparently guided by reason are in reality purely instinctive. Thus the building of a nest by a bird must, at any rate on the first occasion, be a purely instinctive action. The creature cannot know what it is doing. Nor can it have any thoughts on the matter; it suddenly becomes an automaton, a machine, acting thoughtlessly and instinctively.
Some internal force which is irresistible compels it to seek twigs and weave them into a nest. The bird has no time to stop and think what it is doing, nor does itwish to, for it enjoys nest building. It is, of course, impossible for a human being to understand the frame of mind of a bird when building its first nest. The only approach to it that we ever experience is when we are suddenly seized with an impulse to do something unusual, and we obey the impulse and are afterwards surprised at ourselves.
There is a story told of a wealthy man who had been out hunting and was returning home tired and thirsty. He dismounted at a farm-house, went inside and asked for a drink. While this was being obtained he noticed a lot of valuable old china on the dresser: seized by a sudden impulse, he knocked it all down, piece by piece, with his riding whip. His hostess on her return with the drink looked surprised. The hunting man smiled, asked her to name the value she set on the china, sat down and, there and then, wrote out a cheque for the amount.
It always seems to me that when a bird begins for the first time to collect materials for a nest she must act impulsively, without thinking what she is doing. Just as the hunting man was seized with a sudden desire to smash the crockery with his whip, so is she suddenly impelled to collect twigs and build a nest.
Another instinctive act which is apparently purposeful is the feigning of injury by a parent bird when an enemy approaches its young. Superficial observation of this action leads the observer to imagine that the mother bird behaves thus with deliberate intent to deceive, that in so doing she consciously endeavours to distract attention while her young ones are betakingthemselves to cover. As a matter of fact, the bird will behave in precisely the same way if she have eggs instead of young ones. This has, of course, the effect of drawing attention to the eggs, and proves that the action is instinctive and not the result of reasoning.
Most people have remarked the cautious manner in which many birds approach the nest when they are aware that they are being watched. This has the appearance of a highly intelligent act. It is, however, nothing of the kind.
I have taken young birds from a nest, handled them and replaced them in full view of their frantic parents. Then I have retired a short distance and watched the parents. These invariably display the same caution in approaching the nest as they did before I had discovered its whereabouts.
Birds and beasts think much less than they are popularly supposed to do. It is absurd to attribute to them reasoning powers similar to those enjoyed by man; it is equally absurd to assert that they do not think at all.
Two Indian birds have a world-wide reputation. Every one has heard of the weaver bird (Ploceus baya) and the tailor-bird (Orthotomus sutorius). Their wonderful nests are depicted in every popular treatise on ornithology. They are both master-craftsmen and deserve their reputation. But there are in India birds who build similar nests whose very names are unknown to the great majority of Anglo-Indians. The Indian wren-warbler (Prinia inornata) weaves a nest quite as skilfully as the famous weaver bird. This neglected craftsman is common in nearly all parts of India, and, if you speak of the weaver bird to domiciled Europeans, they will think you mean this wren-warbler, for among such he is universally called the weaver bird; the famous weaver, whose portrait appears in every popular bird book, is known to them as the baya.
As its name implies,Prinia inornatais a plainly attired little bird. Its upper parts are earthy brown. It has the faintest suspicion of a white eyebrow, and its under plumage is yellowish white, the thighs being darker than the abdomen. Picture a slenderly built wren with a tail three inches in length, which looks asthough it were about to fall out and which is constantly being waggled, and you have a fair idea of the appearance of this little weaver. But this description applies to dozens of other birds found in India. The various warblers are so similar to one another in appearance as to drive ornithologists to despair. The inimitable “Eha” admits that they baffle him. “There is nothing about them,” he writes, “to catch the imagination of the historian, and they will never be famous. I have been perplexed as to how to deal with them. . . . To attempt to describe each species is out of the question, for there are many, and they are mostly so like each other that even the title ornithologist does not qualify one to distinguish them with certainty at a distance. If you can distinguish them with certainty when you have them in your hand you will fully deserve the title.”
It is, however, possible to recognise the Indian wren-warbler by its note. When once you have learned this you are able to identify the bird directly it opens its mouth. But how shall I describe it? It is a peculiar, harsh but plaintive,twee, twee, twee; eachtweefollows close upon the preceding one, and gives you the idea that the bird is both excited and worried. If you see a fussy little bird constantly flitting about in a cornfield and uttering this note, you may be tolerably certain that the bird is the Indian wren-warbler. It never rises high in the air; it is but an indifferent exponent of the art of flying. It moves by means of laborious jerks of its wings. It is a true friend to the husbandman, since it feeds exclusively on insects. The most remarkable thing about it is its nest. This is a beautifully wovenstructure, composed exclusively of grass or strips of leaves of monocotyledonous plants which the bird tears off with its bill. These strands are invariably very narrow, and are sometimes less than one-twentieth of an inch in breadth. The nest may be described as an egg-shaped purse, some five or six inches in depth and three in width, with an entrance at one side, near the top. It is devoid of any lining, and its texture puts one in mind of a loosely made loofah. The nest is sometimes attached to two or more stalks of corn, or more commonly it is found among the long grasses which are so abundant in India. When the nest is built in a cornfield the birds have to bring up their family against time. They are unable to begin nest-building until the corn is fairly high, and must, if the young are to be safely started in life, have brought them to the stage when they are able to leave the nest by the time the crop is cut.
In India nearly every field of ripe corn has its family of wren-warblers; the two parents flit about, followed by a struggling family of four. These little birds do not by any means always defeat time. Numbers of their nests containing half-fledged young are mown down at every harvest by the reaper’s sickle. The nest is woven in a manner similar to that adopted by the baya; the cock and hen in each case work in combination. Its texture is looser than that of the more famous weaver, but it is not less neatly put together. In it are deposited four or five pretty little green eggs, marked with brown blotches and wavy lines.
Our second neglected craftsman is a tailor. It sewsa nest so like that of the world-famous tailor as to be almost indistinguishable from it. Some authorities declare that the two nests are distinguishable. They assert that the nest ofOrthotomusis invariably lined with some soft substance, such as cotton-wool, the silky down of the cotton tree, soft horse-hair, or even human hair, while that of the species of which we are speaking is lined with grass or roots. This distinction does not, however, invariably hold. I have seen nests of this species which have been lined with cotton-wool.
This bird is known to ornithologists as the ashy wren-warbler (Prinia socialis). Anglo-Indian boys call it the tom-tit. It is a dark ashy-grey bird, with the sides of the head and neck and the whole of the lower plumage buff. There is a tinge of rufous in the wings and tail. It is most easily distinguished by the loud snapping noise it makes during flight. How this noise is produced we do not know for certain. Reid was of opinion that the bird snapped its long tail. What exactly this means I do not know. Jesse believes that the sound is produced by the bird’s mandibles. I have spent much time in watching the bird, and am inclined to think that the noise is caused by the beating of the wings against the tail. This last is constantly being wagged and jerked, and it seems to me that the wings beat against it as the bird flits about. When doves and pigeons fly, their wings frequently meet, causing a flapping sound. I am of opinion that something similar occurs when the ashy wren-warbler takes to its wings.
Perhaps the most extraordinary thing about this bird is the well-authenticated fact that it builds two types ofnest. Besides this tailor-made nest, the species makes one of grass, beautifully and closely woven, domed, and with the entrance near the top. I have never seen this latter type of nest, but so many ornithologists have that there can be no doubt of its existence.
The strange thing is that both types of nest have been found in the same neighbourhood, so that the difference in the form of nursery is not a local peculiarity.
I am at a loss to account for the existence of these two types of nest. I have no idea how the habit can have arisen, nor do I know what, if any, benefit the species derives from this peculiarity. So far as I am aware, no one can say what it is that leads to the construction of one type of nest in preference to the other. The nests of this species present a most interesting ornithological problem. I hope one day to be in a position to throw some light on it; meanwhile I shall welcome the news that some one has forestalled me. The ashy wren-warbler is a common bird, so that most Anglo-Indians have a chance of investigating the mystery. The same kind of eggs are found in each type of nest. They are of exceptional beauty, being a deep mahogany or brick-red, so highly polished as to look as though they have been varnished.
Just as every Englishman is of opinion that his house is his castle, so does every little bird resent all attempts at prying into its private affairs in the nest. For this reason we really know very little of the home-life of birds. It is not that there are no seekers after such knowledge. Practical ornithology is a science that can boast of a very large number of devotees.
Many men spend the greater part of their life in endeavouring to wrest from birds some of their secrets, and such must admit that the results they obtain are as a rule totally disproportionate to the magnitude of the efforts. At present we know only the vague generalities of bird life.
We know that the hen lays eggs; that she, with or without the help of the cock, as the case may be, incubates these eggs; that the young, which are at first naked, are fed and brooded until they are ready to leave the nest, when they are coaxed forth by the parents, who hold out tempting morsels of food to them. But these are mere generalities. Our ignorance of details is very great.
The nests of most passerine birds are scrupulously clean. Young birds have enormous appetites, and much of thefood which they eat is indigestible and must pass out as droppings, yet in the case of many species no sign of these droppings is visible, either in the nest, or on the leaves, branches, or the ground near the nest. What becomes of these droppings? Ornithological treatises are silent upon this subject.
Again, young birds are born naked, and in India are frequently exposed to very high temperatures, so that much liquid must pass from their bodies by evaporation. How is this liquid made good? Do the parents water the birds, if so, how? I have never seen any mention of this in an ornithological treatise.
Let us to-day consider these two subjects: the sanitation of the nest and the method of assuaging the thirst of young nestlings.
As regards the first we have some knowledge, thanks to the patient labours of Mr. F. H. Herrick, an American naturalist, whose book,The Home Life of Birds, I commend to every lover of the feathered folk. Unfortunately, Mr. Herrick’s book is to some extent spoiled for Englishmen, because it deals with birds with which they are unfamiliar; nevertheless, its general results apply to all passerine birds.
Mr. Herrick is a very keen bird photographer. As every one knows, he who wishes to obtain good photographs of birds has two great difficulties to overcome. The first is to get near to his subjects, and the second is to find them and their nests in situations suitable for photography.
The former is usually overcome by the photographer concealing himself and his camera in a tent or otherstructure. At first the birds are afraid of the concealing object, but soon maternal affection overcomes their fear.
Mr. Herrick’s method of overcoming the second of these two difficulties is to remove the nest to be photographed from the concealed situation in which it is usually built, and place it in a more open place. If the nest be thus moved when the young are some seven or eight days old, the parents will almost invariably continue to feed their young in the new situation, for at that particular period the parental instinct is at its zenith. In addition to obtaining a splendid series of photographs, Mr. Herrick has observed, from a distance of a few inches, the nesting habits of several American birds. As the result of these observations he is able to declare that nest-cleaning follows each feeding with clock-like regularity. “The excreta of the young,” he writes, “leave the cloaca in the form of white opaque or transparent mucous sacs. The sac is probably secreted at the lower end of the alimentary canal, and is sufficiently consistent to admit of being picked up without soiling bill or fingers. The parent birds often leave the nest hurriedly bearing one of these small white packages in bill, an action full of significance to every member of the family. . . . Removing the excreta piecemeal and dropping it at a safe distance is the common instinctive method, not only of insuring the sanitary condition of the nest itself, but, what is even more important, of keeping the grass and leaves below free from any sign which might betray them to an enemy.” These packets of excrement are quite odourless,and they are often devoured by the parent bird instead of being carried away. The digestion of very young birds must be feeble, and doubtless much of the food given them passes undigested through the alimentary canal, so that it is capable of affording nourishment to the parents. Birds are nothing if not economical.
Of course, all birds are not so careful of the sanitation of the nest. Every one knows what a filthy spectacle a heronry is. According to Mr. Herrick, the instinct of inspecting and cleaning the nest is mainly confined to the great passerine and picarian orders. It is obviously not necessary in the case of those birds, such as fowls, of which the young are able to run about when born; nor is it needful in the case of birds of prey, who take no pains to conceal the whereabouts of the nest. Young raptores eject their semi-fluid excreta over the edge of the nursery; thus the nest is kept clean, but the droppings on the ground betray its presence to all the world.
Coming now to our other question: How do young birds obtain the water which they require? we have no help from Mr. Herrick. He makes no mention of this in his most interesting book. It is possible that nestlings are not given anything to drink, that the juicy, succulent insects or fruits with which they are supplied contain sufficient moisture for their requirements. We must remember that the skin of birds is very different from that of man. It contains no sweat glands, so that a bird, like a dog, can only perspire through its mouth.
The breath of mammals is so surcharged with moisture that when it is suddenly cooled the water vapour in it condenses; the result is we can “see the breath”of a mammal on a cold day. I have never succeeded in seeing a bird’s breath, so am of opinion that the fowls of the air do not exhale so much moisture as mammals do. But even allowing for this, a considerable amount of moisture must be given out in expiration, so that it seems probable that young birds require more moisture than they obtain in their food. Drops of water have to be administered to hand-reared birds. Many birds fill up the crop with food and then discharge the contents into the gaping mouths of their young. In this condition the food must be mixed with a considerable quantity of saliva and possibly with water. The crop of a bird is a receptacle into which the food passes and remains until actually utilised. There seems no reason why water should not be stored for a short time in this receptacle just as food is. Perhaps birds “bring up” water as they do solid food, and thus assuage the thirst of their young. Such a process would be very difficult to detect; it would be indistinguishable from ordinary feeding to the casual observer. I hope that some physiologist will take up the matter. A quantitative analysis of the air exhaled by a bird should not be very difficult to make.