Part 3
The adjutant bird (_Leptoptilus dubius_) is one of Nature’s little jokes. It is a caricature of a bird, a mixture of gravity and clownishness. Everything about it is calculated to excite mirth—its weird figure, its great beak, its long, thin legs, its conspicuous pouch, its bald head, and every attitude it strikes. The adjutant bird is a stork which has acquired the habits of the vulture. Forsaking to a large extent frogs and such-like delicacies, which constitute the normal diet of its kind, it lives chiefly upon offal. Now, most, if not all, birds which feed on carrion have the head and neck devoid of feathers. This arrangement, if not ornamental, is very useful. The bare head and neck are, as “Eha” remarks, “the sleeves tucked up for earnest work.” The adjutant forms no exception to the rule, it wears the badge of its profession. But let me here give a full description of this truly comic bird. It stands five feet in its stockings. Its bill is over a foot in length and correspondingly massive. As we have seen, the whole head and neck are bare, except for a few feathers scattered over it like the hairs on an elephant’s head. The bare skin is not lacking in colour. On the forehead it is blackish; it becomes saffron-yellow on the upper neck, while lower down it turns to brick-red. There is a ruff of white feathers round the base of the neck. This ruff, of course, appears entirely out of place and adds to the general grotesqueness of the bird. The back and wings are ashy black, becoming slaty grey at the breeding season. The lower parts are white.
As if the creature, thus arrayed, were not sufficiently comic, Nature has given it a great pouch which dangles from the neck. This is over a foot in length and hangs down like a bag when inflated. It is red in colour, spotted with black. Its situation naturally leads one to believe that it is connected with the gullet, that it is a receptacle into which the bird can hastily pass the garbage it swallows pending more complete disposal. But it is nothing of the sort. It does not communicate directly with the œsophagus. Knowing this, one is able to appreciate to the full the splendid mendacity of the writer to _Chambers’s Journal_ in 1861, who declares that he witnessed an adjutant swallow a crow which he watched “pass into the sienna-toned pouch of the gaunt avenger. He who writes saw it done.”
Note the last sentence. The scribe was evidently of opinion that people would not believe him, so thought to clinch matters by bluffing! But, to do him justice, it is quite possible that he did see an adjutant swallow a crow, for other observers have witnessed this, but the remainder of the story rests upon the sandy foundation of the imagination. If the truth must be told, we do not know for certain what the use of this pouch is. Blyth suggested that it is analogous to the air cell attached to one lung only of the python or the boa-constrictor, and, as in that case, no doubt supplies oxygen to the lungs during protracted meals. The bird can thus “guzzle” to its heart’s content without having to stop every now and then to take a “breather.”
But we must return to the appearance of the bird, for the account of this is not yet complete, since no mention has been made of the eye. This is white and very small, and so gives the bird a wicked, knowing expression, like that of an elephant. Colonel Cunningham speaks of “the malignantly sneaking expression of the pallid eyes.” This is perhaps a little severe on the adjutant, but it is, I fear, quite useless to deny the fact that he has “a canister look in his heye.”
A mere description of the shape and colouring of the adjutant does not give any idea of his comicality. It is his acts rather than his appearance that make him so ludicrous. Except when floating high above the earth on his great pinions the bird always looks grotesque. To say that he, as he walks along, recalls a hunchbacked old man who is deliberately “clowning” is to give a hopelessly inadequate idea of the absurdity of his movements. Lockwood Kipling is nearer the mark when he says: “For grotesque devilry of dancing the Indian adjutant beats creation. Don Quixote or Malvolio were not half so solemn or mincing, and yet there is an abandonment and lightness of step, a wild lift in each solemn prance, which are almost demoniacal. If it were possible for the most angular, tall, and demure of elderly maiden ladies to take a great deal too much champagne and then to give a lesson in ballet dancing, with occasional pauses of acute sobriety, perhaps some faint idea might be conveyed of the peculiar quality of the adjutant’s movements.”
Sometimes the bird struts along solemnly with bent back and forwardly pointed bill, at others it will jump or skip along with outstretched wings and clap its beak. It cannot even stand still without striking ludicrous attitudes. Seen from behind, it looks like a little hunch-backed old man with very thin legs, dressed in a grey swallow-tail coat. Adjutants sometimes vary the monotony of existence by standing on one leg; occasionally they sit down, stretching their long legs out in front, and looking “as though they were kneeling wrong side foremost.”
Colonel Cunningham gives a most entertaining account of the habits of these birds, many of which used, until quite recently, to be seen about Calcutta. My observations are chiefly confined to birds in captivity; this perhaps accounts for the fact that they do not agree in all respects with those of the Colonel. According to him, adjutants “are singularly ill-tempered birds, constantly squabbling with one another, even in the absence of any cause of competition, such as favourite roosts or specially savoury stores of offal. Even whilst several of them are standing quietly about, sunning themselves and apparently buried in deep thought, a quarrel will suddenly arise for no apparent reason; and then you may see two monstrous fowls begin to pace around, cautiously stalking one another, and watching for a favourable opportunity of striking and buffeting with beak and wings. The expression of slow malignity with which such duellists regard one another is gruesome, and the injuries resulting from the fray are often ghastly; blinded eyes and bloody cockscombs being matters of everyday occurrence.”
Captive adjutants seem to be most placid birds. There are three of them in the “Zoo” at Lahore, kept in a large park-like enclosure, and I have never seen these fighting. They appear to be always, if not on the best of terms, at any rate, indifferent to one another. The three will stand for many minutes at a time in a row, motionless as statues. Sometimes a male and a female will huddle up to one another and remain thus, with their heads almost touching, looking like caricatures of Darby and Joan.
The table manners of adjutants, like those of most other carrion feeders, are not polite. I will therefore not attempt to describe them. In the good old days, feeding adjutants used to be a favourite pastime of Mr. Thomas Atkins at Calcutta. I regret to have to say that his motives were not always purely philanthropic. To connect two pieces of meat by a long string and then throw them among a crowd of adjutants savours of practical joking. One bird, of course, swallows one piece of meat, while a second adjutant secures the other morsel. All goes well until each of the birds tries to go its own way—then a tug-of-war results, fraught with gastronomical disturbance to the combatants.
Adjutants are nowhere very abundant; they are nevertheless spread over the whole of Northern India, but do not appear to be found so far south as Madras. Another species, however—the smaller adjutant (_L. javanicus_)—has been observed on the Malabar coast.
Some natives make adjutant-catching their profession. The birds are captured on account of their down-like feathers, which are of considerable commercial value.
The catcher fits the skin of an adjutant over his head and shoulders, and in this attire creeps up to a company of the birds as they stand half-asleep, knee-deep in water. Great is the surprise of the unsuspecting birds when one of them is unceremoniously seized by the wolf in the adjutant’s skin.
THE SARUS
Having discoursed upon the adjutant, it seems but fitting that we should turn our attention to another long-shanked gentleman—the sarus. The adjutant is, as we have seen, a stork, while the sarus is a crane. I do not know whether this conveys very much information to the average mind. Most people will, I imagine, “give it up” if asked, “What is the difference between a stork and a crane?” Yet there are considerable differences between the two; they belong to different families, and, like rival tradesmen of the same name, “have no connection with one another.” I do not propose to detail the anatomical differences between storks and cranes, for the excellent reason that I myself do not know them all, nor have I the least intention of acquiring such knowledge. It forms part of the dry bones of science, and these are best left to museum ornithologists to squabble over. There are, however, one or two simple points which suffice to enable us to distinguish at a glance a crane from a stork. The hind toe of the stork is well developed, while that of the crane is small and does not touch the ground; the consequence is that the stork likes to rest on trees, while the crane prefers to stand on _terra firma_ on its flat feet. The nostrils of the crane are half-way down the beak, while they are at the base in the bill of the stork. The crane nests on the ground; the stork builds in a tree. Young storks are helpless creatures, while little cranes hop and run about from the moment they leave the egg. Lastly, the crane has a voice, a fine loud voice, a voice that can be heard a mile away, a voice like a trumpet, for its windpipe is coiled. King stork, on the other hand, has no voice; when he wants to make a joyful noise he is obliged to clap together his great mandibles.
Cranes have been favourites with man from time immemorial. The result is that ancient and mediæval writers have plenty to say about them. Now the naturalist of old considered himself in honour bound to attribute some wonderful characteristic to every beast of which he wrote. If he did not know of any clever thing done by any creature, he invented something for it to do. This method had the advantage of making natural history a very exciting and interesting study. Cranes were supposed to perform all manner of tricks with stones. As we have seen, they are blessed with powerful voices, and, like other loud-voiced people, find it difficult to keep silent. They are fully persuaded that silence is golden; but, when it comes to acting up to this belief, the flesh proves itself very frail. Thus it came to pass that the sagacious birds, when migrating, used to stop up their mouths with stones. As they are far too well-bred to speak with the mouth full, they were able to maintain a decorous silence when travelling.
I can cite plenty of authority for this statement. There is, in particular, no less a personage than “Robert Tanner, Gent. Practitioner in Astrologie and Physic.” “The cranes,” he writes, “when they fly out of Cilicia, over the mountain Taurus, carried in their mouths a pebble stone, lest by their chattering they should be seized upon by eagles.”
The cranes had yet another use for their stones. When the main body were resting at night, sentinels were posted to guard against surprise, so that the company could go to sleep in security. To ensure necessary vigilance, the sentinels stood on one foot and held in the other a large stone. If they inadvertently nodded, their muscles relaxed and the stone dropped. This, of course, used to wake them up. Even Alexander the Great was glad to learn a lesson from the cranes. He used to go to roost with, not a stone in his hands, but a silver ball, as more befitting his royal dignity. On the slightest movement the ball would fall and he wake up. Thus it was that he never overslept himself. We do not do such heroic things nowadays; nor do cranes.
Cranes are birds which will not stand nonsense. The pigmies used to go egg-collecting among them; the result of this was, to translate Homer:—
When inclement winters vex the plain, With piercing frosts, or thick descending rain, To warmer seas the cranes embodied fly, With noise and order, through the midway sky: To pigmy nations wound and death they bring.
Notice that as the cranes were on the war-path there was no necessity for them to fill their mouths with stones; they wanted all their lung power to bark at their pigmy foes.
Having considered cranes as they are not, it behoves us to glance at them as they are. The sarus is a handsome creature. It stands over five feet high. The general colour of the plumage is a beautiful French grey. The head and long neck are devoid of feathers, but are covered with numerous tiny crimson warts or papillæ. These assume a deeper hue at the breeding season, which occurs from July to September. There is a patch of grey on the sides of the head. The throat and a ring round the nape are covered with black hairs.
Saruses feed upon vegetable substances, insects, earthworms, frogs, lizards, and other small reptiles, with an occasional snake thrown in by way of condiment. “This,” remarks Babu Ram Brama Sanyal, “shows the kind of accommodation they must have.”
Saruses are not gregarious birds, but hunt in couples and are said to mate for life. It is further asserted that when one of a pair is killed the other pines away and dies. I believe this to be true, although I cannot vouch for it, and am certainly not going to put the statement to the test by shooting one of a pair: for these cranes are such tame, confiding birds that to shoot them savours strongly of murder.
According to Jerdon, a young sarus is not bad eating, but old birds are worthless for the table. Lucky old birds! Saruses thrive very well in captivity. As they habitually indulge in all manner of eccentric dances they make most amusing pets. They are usually gentle and let strangers caress them and tickle their heads. But I always let others try this on for the first time with a strange crane, because some birds resent this head-tickling and, to again quote from the worthy Babu above mentioned, “appear to exist only as it were for pecking at everything, bird, beast, and man: children being the special object of their wrath.”
There are two cranes in the “Zoo” at Lahore; they are a most mischievous couple. They used to be kept with the ducks and geese, and amused themselves by rooting up all freshly planted rushes. At feeding time it was their habit to hop from one dish of food to another with outstretched wings and thus frighten off the ducks and secure the lion’s share for themselves. They were then removed to the enclosure where the adjutants are. They started playing tricks on these, but the adjutant has a powerful beak which he is quite ready to use when necessity arises. The result is that the saruses are not on speaking terms with the adjutants.
Unlike the adjutant, whose nest is a huge platform of sticks placed on the top of a very lofty tree, the sarus builds its nursery on the ground. This takes the form of a large cone, several feet in diameter at the base and two or three feet high. It is composed of reeds, rushes, and straw, and placed by preference in shallow water. Great care is taken to keep the eggs above water level. If, as is apt to happen in India, heavy rain comes on after the completion of the nest, the parents speedily set to work to raise the eggs by adding more material to that upon which they rest.
THE STABILITY OF SPECIES
If two crows be taken to an ornithologist and he be told that one of them was caught in the Himalayas while the other was captured in Madras, he will not be able to tell which individual came from which area: in other words, the crows of Madras resemble those of the Himalayas. This, of course, is no unusual phenomenon. The same may be said of the myna, the king-crow, and a great many other birds and beasts. Yet the phenomenon is a remarkable one if we take into account the facts of variation.
If several hundred thousand crows be collected and carefully examined, it will be found that no two of them resemble one another in all respects. This being so, we should expect the crows of Madras to differ from those of the Himalayas, since the two environments are so dissimilar. We may say with tolerable certainty that no intercrossing takes place between the crows of the two localities: for these birds are stay-at-home creatures, and do not wander far afield. In this case, therefore, it is not intercrossing that has prevented the origin of local races.
A consideration of the main causes which conduce to the stability of species may not be devoid of interest; for the subject is one which has hitherto attracted but little attention. Since the Darwinian hypothesis was given to the world we have heard so much of variation and the origin of new species that the other phenomenon—that of the fixity of species—in spite of varying environments has been almost entirely overlooked. Yet it was just this feature of animal life that attracted the attention of the older zoologists and led them to believe that species had been created once and for all, and that, when created, they were immutably fixed.
Most biologists, if asked to explain the comparative fixity of species, the slowness of evolution, would, I think, refer to the fact that variations appear to take place indiscriminately in all directions. Take, for example, a large number of birds of any species and measure any one organ, let us say the first primary wing feather. Suppose the average length be six inches. We shall find that in a considerable percentage of the individuals measured the wing is exactly six inches in length: that six inches is what we may call the favourite or fashionable length of the wing. The next commonest lengths will be 5.99 and 6.01 inches, and so on. We shall find that only a very small percentage of the individuals have wings shorter than 5½ inches or longer than 6½ inches; and if we measured a thousand individuals we probably should not find any in which the wing was shorter than five inches or longer than seven.
Now, the commonly accepted theory is that in those cases where there is free interbreeding the long-winged varieties and the short-winged varieties tend to neutralise one another, hence no change in character takes place. The effects of variation are swamped by intercrossing. It is only when intercrossing is checked, as when natural selection weeds out certain varieties, that evolution occurs.
This theory, of course, explains, or helps to explain, why species are so stable; but it involves the assumption that there is no such thing as sexual selection among animals in a state of nature. The theory assumes that individuals mate in a haphazard manner, that a long-winged hen is as likely to select a short-winged husband as a long-winged one. Are we justified in assuming this? At present there is little evidence on the subject. Evidence can only be procured by measuring a number of pairs of birds that have mated, and seeing whether large hens mate chiefly with large cocks or with small cocks, or indifferently with large or small cock-birds.
That sexual selection is a reality and not a mere hypothesis there can, I think, be but little doubt. It is with the theory that supposes that the females alone exercise selection that I feel compelled to quarrel. The male selects his partner just as much as the female selects hers. The choice is mutual.
In the Zoological Gardens at Lahore there are a number of ordinary coloured peacocks and a number of albinos. No coloured hen will mate with a coloured cock if she is allowed to exercise a choice between him and an albino. Here, then, is a clear example of sexual selection.
Professor Karl Pearson has spent much time in trying to discover whether there is such a thing as sexual selection—what we may call unconscious selection—among human beings. His experiments tend to show that there is.
If we take a thousand married men whose stature is not less than six feet, and a thousand also who are none of them taller than 5 ft. 8 in., we shall find that the average height of the wives of the former is greater than that of the wives of the shorter men.
If wild animals display a similar characteristic, it is evident that to say that intercrossing swamps variation and causes species to remain stable is not altogether accurate; for, if like select like as partners, we should expect a number of races to rapidly arise, or, at any rate, three races—a large, medium, and small one. So far, however, as we can see, species display no such tendency. We are therefore driven to the conclusion either that there is among species in a state of nature no tendency for like individuals to select like as their partners, or, if there be such a tendency, there is some force at work which counteracts it.
It may be thought that the case of the peafowl in the Lahore “Zoo” tends to show that among animals it is dissimilarity, not similarity, that attracts, for the coloured hens mate with white cocks in preference to those like themselves.
As a matter of fact the hens select the white cocks, not because they are white, but because of the strength of the sexual instincts of these latter. The white cocks continually show off before the hens; the sexual desire is developed more highly in them than in the ordinary cocks, and it is this that attracts the hens.
We must also bear in mind that abnormal variations have a strong tendency to perpetuate themselves. If a white cock mates with an ordinary peahen, the majority of the offspring are pure white.
If there be such a thing as sexual selection, and if it be, as I believe, the strongest, the most mettlesome individuals, those in which the sexual instincts reach the highest development, that attract the opposite sex, then the question arises: is there any connection between these characteristics and the size and colour of their possessor? We are not in possession of sufficient data to answer this question in the affirmative. Nevertheless I believe that such a relation does exist.
The researches of Professor Pearson seem to point to the fact that there exists a definite relation between variation and fertility. For every species there is a mode or typical size and form, and from this there are deviations in all directions, and, speaking generally, the greater the deviation from the mode the less the fertility of the individual.
If this be a general law we have here a very potent factor tending to make species stable. Those individuals which deviate least from the common type are the most fertile; they produce the most offspring; moreover, they are the most numerous, hence they, by sheer force of numbers, keep a species stable. The abnormal individuals are comparatively few in number, and they beget comparatively few of their kind, so have no chance of establishing themselves and crushing out the normal type, unless natural selection steps in to their aid.
Is comparative infertility the result of feebleness of the sexual instinct? If so, sexual selection must be conducive to the stability of species.
For if the rule be the greater the deviation of an individual from the normal the less the development in it of the sexual instinct and the less its fertility, it follows that an abnormal organism is less likely to find a mate than a normal individual is; and if it do succeed in forming a union, that union will probably produce less than the average number of offspring.
THE AMADAVAT