Part 13

It would be wearisome to detail all the kinds of nest into the composition of which cobweb enters. Sufficient has been said to show that this very useful substance is the favourite cement of bird masons.

XXXII INDIAN FLY-CATCHERS

There exist in the Indian Empire no fewer than fifty-one species of fly-catcher. This fact speaks volumes for the wealth of both the bird and the insect population of India. Fly-catchers are little birds that feed exclusively on insects, which they secure on the wing. Their habit is to take up a strategic position on some perch, usually the bare branch of a tree, whence they make sallies into the air after their quarry. Having secured the object of their sortie—and this they never fail to do—they return to their perch. A fly-catcher will sometimes make over a hundred of these little flights in the course of an hour; the appetite of an insectivorous bird appears to be insatiable. All fly-catchers obtain their food in this manner, but all birds which behave thus are not members of the fly-catcher family. As fly-catchers are characterised by rather weak legs, and, in consequence, do not often descend to the ground, they are of necessity confined to parts of the country well supplied with trees. Thus it comes to pass that the great majority of fly-catchers are found only in well-wooded hill tracts. Four or five species, however, occur commonly in the plains. With two of these—the glorious paradise fly-catchers (Terpsiphone) and the very elegant fan-tail fly-catchers (Rhipidura)—I have dealt in my former books. I therefore propose to confine myself to some of the many other species. Of these last, the brown fly-catcher (Alseonax latirostris) is the one most frequently met with in the plains. This is the most inornate of all the fly-catchers. As its name implies, brown is its prevailing hue. Its lower parts are, indeed, whitish, and there is an inconspicuous ring of white feathers round the eye, but everything else about it is earthy brown. It is the kind of bird the casual observer is likely to pass over, or, if he does happen to observe it, he probably sets it down as one of the scores of warblers that visit India in the cold weather. It is only when the bird makes a sudden dash into the air after an insect that one realises that it is a fly-catcher. The brown fly-catcher is an Ishmaelite. It seems never to remain for long in one place, and, although it may be seen at all times of the year, its nest does not appear ever to have been found in this country.

A more ornamental fly-catcher which occasionally visits the plains is the grey-headed fly-catcher (Culicapa ceylonensis). In this species the head, neck, and breast are ash-coloured, the wings and tail are dark brown, the back greenish yellow, and the lower parts dull yellow. This fly-catcher is common both in the Nilgiris and the Himalayas. It has the usual habits of the family. Like the majority of them it is no songster, although it frequently emits a cheeping note. Its nest is a very beautiful structure, a ball of moss which is attached to a moss-covered tree or rock, more often than not near a mountain stream.

Fly-catchers usually nidificate in the neighbourhood of water, because that element favours the existence of their insect food.

Siphia parva—the European red-breasted fly-catcher—is a species which visits the plains of India in the cold weather, but not many individuals penetrate so far south as Madras. This bird is easily recognised, since the cock bears a strong likeness to the familiar English robin red-breast. I may here mention that an allied species—the Indian red-breasted fly-catcher, S. hyperythra—summers in Kashmir and winters in Ceylon, but, curiously enough, it has not been recorded from the plains of India. It would thus seem to fly from Kashmir to Ceylon in a single night. Even so, it would be very extraordinary if an occasional individual did not fail to perform the whole journey in so short a space of time; therefore, this species should be watched for in South India in spring and autumn. It is easily distinguished from allied species by a black band which surrounds the red breast and abdomen.

As it is impossible to detail in one brief essay all the species of fly-catcher found in the Indian hills, I propose merely to mention those that are most common in the Nilgiris and the Himalayas, and then to make a few observations on fly-catchers in general. In addition to the fan-tail, the grey-headed and the brown fly-catchers, the following species are abundant in the Nilgiris: Tickell’s blue fly-catcher (Cyornis tickelli), the Nilgiri blue fly-catcher (Stoparola albicaudata), and the black and orange fly-catcher (Ochromela nigrirufa). In the Himalayas, the paradise fly-catcher is common in summer at lower altitudes. Above 6000 feet elevation the following are the species most commonly seen: the grey-headed fly-catcher, the white-browed blue fly-catcher (Cyornis superciliaris), and the beautiful verditer fly-catcher (Stoparola melanops), which is no mean songster.

Fly-catchers form a most interesting group of birds. It is, I maintain, quite impossible for any man possessed of a logical mind to contemplate this family without discovering that the theory of natural selection is utterly inadequate to account for the variety of animal life that exists upon the earth. The habits of practically all the fly-catchers are identical. They all dwell in an arboreal habitat; nevertheless, the various species display great dissimilarity in outward appearance. Some species are brightly plumaged, others are as dully clad as a bird can possibly be. Some have crests and long tails, others lack these ornaments. The adult cock paradise fly-catcher, with his long, white, satin-like tail feathers, is the most striking of birds, while the brown fly-catcher is less conspicuously attired than a hen sparrow. This is not the only difficulty presented to the theory of natural selection by fly-catchers. In some species, as, for example, the paradise fly-catcher, the sexes are altogether dissimilar in appearance, while in others the most practised eye cannot distinguish between the cock and the hen. Nor does there appear to be any connection between nesting habits and the presence or absence of sexual dimorphism. The fan-tail fly-catchers, in which the sexes are alike, and the paradise fly-catchers, in which they differ widely, both build little cup-shaped nests in the lower branches of trees, and in both the cock shares with the hen the duty of incubation. Again, the verditer and the white-browed blue fly-catchers build their nests in holes in trees; yet in the former both sexes are blue, while in the latter the cock only is blue.

Further, in the fly-catchers we see every gradation of sexual dimorphism, from a difference so slight as to be perceptible only when the sexes are seen side by side, to a difference so great as to make it difficult to believe that the sexes belong to one and the same species. It must, therefore, be obvious to any sane person that neither natural nor sexual selection can be directly responsible for the colouration of many species of fly-catcher.

Another interesting characteristic of the fly-catchers is the total absence of green in the plumage of any of them. They are birds of a variety of colours; they display many shades of blue, yellow, orange, red, grey, and brown, also black and white; but not one carries any green feathers. Yet they are essentially arboreal birds, so that green would be a very useful colour to them from the point of view of protection from enemies. From the fact, then, that none of the fly-catchers are green, we seem to be compelled to infer that there is something in their constitution that prevents green variations appearing in their plumage.

In conclusion, note must be made of the fact that fly-catchers, although they subsist almost entirely upon insect diet, appear but rarely to devour butterflies. I have watched fly-catchers closely for several years, and have on two occasions only seen them chase butterflies or moths. Five years ago in Madras I observed a paradise fly-catcher chasing a small butterfly, and recently, in the Himalayas, I saw a grey-headed fly-catcher drop down from a tree and seize a moth that was resting in the gutter. The reason why fly-catchers do not often attack butterflies is obvious; these insects offer very little meat and a great deal of indigestible wing surface. Nevertheless, the theory of protective mimicry is almost exclusively illustrated by examples taken from butterflies. In theory, these creatures are so relentlessly persecuted by insectivorous birds that in order to escape their foes many edible butterflies mimic the appearance of unpalatable species. Unfortunately for theory, few creatures in practice seem to attack butterflies when on the wing, which is just the time when the “mimicry” is most obvious.

The elegant little fly-catchers, then, are birds which mock Darwin, laugh at Wallace, and make merry at the expense of Muller and Bates!

XXXIII INSECT HUNTERS

Fly-Catchers, although they subsist almost entirely on insects, are by no means the only insectivorous creatures in existence. They merely form a considerable branch of the Noble Society of Insect Hunters.

If there exist any philosophers in the insect world they must find the uncertainty of life a fitting theme on which to lavish their philosophical rhetoric. Consider for a moment the precariousness of the life of an insect! There exist in India probably over three hundred species of birds which live almost exclusively upon an insect diet. Think of the mortality among insects caused by these birds alone, by the mynas, the swifts, the bee-eaters, the king crows, et hoc genus omne. Then there are insectivorous mammals, to say nothing of man who yearly destroys millions of injurious and parasitic hexapods. Fish too are very partial to insects, while for spiders, frogs, and lizards, life without insects would be impossible. Nor do the troubles of insects end here, they are preyed upon by their own kind, and, strange phenomenon, some plants entrap and destroy them. But we Anglo-Indians cannot afford to sympathise with the insects. In spite of the high mortality of the hexapod tribes, they flourish like the green bay-tree. So prolific are they that, notwithstanding the fact that millions are daily destroyed by their foes, the life of human beings in India becomes a burden on account of the creeping things. In the monsoon the insects tax man almost to the limits of his endurance—they teaze, bite, and worry his person, they destroy his worldly goods, and, not content with this, find their way into his food and drink. For this reason I feel very kindly disposed to the frogs, the lizards, and the fly-catching birds.

It is worth coming to India if only to see a frog or toad at work. Go at sunset, during a break in the rains, on to the chabutra, and place a lamp near you. Thousands of insects of all shapes and sizes are attracted by the light. In their wake come the toads. A toad always looks blasé. His stupid appearance and sluggish movements give him this air. Watch him as he hops into the zone of light. He advances to within an inch of a resting insect, and, before you can say “Jack Robinson,” the creature has flown into his mouth! The toad takes another hop, and a second insect follows the example of the first; then another and another! Have the insects all suddenly gone mad? Are they bewitched, mesmerised by the ugly face of the toad? Nothing of the kind. The insects have not jumped into the amphibian’s mouth at all. The toad has a long tongue attached at the front end to its mouth. This tongue is covered with sticky saliva and is capable of being protruded and retracted with lightning rapidity. In other words, the toad’s tongue is just a fly-paper, capable of the most perfect manipulation. The unsuspecting insect is resting, and hears not the silent approach of its enemy. Suddenly it is caught up by a great sticky tentacle, then comes oblivion. The toad’s tongue has shot forth and back again so quickly as to be imperceptible to the human eye.

The lizard obtains its food in a similar way. It enters the bungalow and lies up during the day behind a picture. As soon as the lamps are lighted it comes forth as hungry as the proverbial hunter. In a single night it devours hundreds of insects. I have watched a lizard feeding in this way until he had consumed so many insects that he could scarcely move: and doubtless he would have continued his gluttonous meal but for the fact that he had become as slow as Mark Twain’s jumping frog after it had partaken copiously of shot! The lizard cannot shoot out his tongue to the extent that the frog can, so he has to make a dash at each insect before swallowing, and, to his credit, it must be said that he rarely lets a victim escape him unless, of course, he has over-eaten himself.

Although I am very fond of the nimble little gecko, I must admit that he is an out-and-out glutton. Sometimes his gluttony leads him to try to capture quarry beyond his capacity. Let me relate an amusing little incident that I recently witnessed. The scene was my dressing-table, and the time 9 p.m. in the month of August; the day I forget. It matters not. A large stag-beetle was crawling laboriously across the dressing-table. Upon this table was an ordinary looking-glass, under which a lizard had taken up his habitation. From his point of view the position was a good one, for the lamp overhead attracted to the table a number of insects which the lizard could watch from under the base of the glass.

The lizard caught sight of the beetle and began to stalk it. Surely, I thought, the lizard will not try to devour that beetle, which is nearly half as big as himself; but, as he emerged from under the glass, I saw that he meant business. Slowly but surely he gained upon the slow-moving beetle. Having arrived close up behind it, he shot forth his sticky tongue. The next moment the beetle found itself lying on a spot eight inches from where it had a second before stood, and the lizard was trembling in his lair. The reptile had apparently expected to find the beetle as soft and luscious as a strawberry, so the instant his tongue felt the hard, chitinous integument of the beetle he drew that organ back pretty smartly. But his tongue was so sticky that the beetle stuck to it for a moment, and so was thrown backwards over the reptile’s head. The lizard was startled at what had happened, so instinctively took cover. The insect too was scared nearly out of its wits, and did what most frightened insects do, that is to say, retracted its legs and remained perfectly motionless. When, however, several minutes passed and nothing happened, the beetle grew bold, and putting forth its legs, began again to crawl on its way. Directly it moved the lizard put himself on the qui vive, and even went so far as again to follow it, but, profiting by his recent experience, did not attempt a second time to swallow it. Thus the beetle passed off the stage.

Seeing that this particular lizard was not over sharp, I determined to play a little practical joke upon it. Taking a piece of black worsted, I rolled it up into a ball about the size of a fine, strapping blue-bottle fly, and, having attached a piece of cotton to it, I dangled this bait before the lizard. I succeeded in “drawing” him. He was on it before I could say “knife.”

In less than a second the worsted was in his mouth, but he dropped it like a hot potato, and then sulked under the looking-glass, apparently greatly annoyed at having been made a fool of twice in succession. The next day I chanced to come upon a toad, busy catching insects. Wondering whether he would be deceived, I threw on to the grass near him the end of a lighted cigarette which I had been smoking. He at once caught sight of it, and sat there looking at it intently for some seconds, and I began to think he would not fall into the trap, but the temptation was too strong, for he shot forth his tongue to seize it. He discovered that the “tongue is an unruly member” as he retracted the smarting organ.

It is therefore clear that some insect-hunters are ever ready to try experiments as regards food.

Fish too, when really hungry, do not appear to exercise much discrimination as to the nature of the “fly” they will take.

The swarming of the “white ants” is a red-letter day for the insect-eating animals, an annual harvest in which they revel. The mynas and the crows do not disdain to partake of this copious meal supplied by nature.

The latter are omnivorous birds; all is grist which comes to their mill—carrion, fruit, locusts, termites, fish, grain, and the crumbs which fall from man’s table.

The mynas too eat a variety of food, but they are first and foremost insectivorous birds. They are never so happy as when chasing grasshoppers on the grass. By preference they accompany cattle, strutting along beside these and catching in their beaks the insects as these latter jump into the air, frightened by the approach of the great quadruped.

The beautiful white cattle egrets (Bubulcus coromandus) in a similar way make buffaloes and kine act as their beaters.

The familiar king crow (Dicrurus ater) adopts two methods of insect-catching. The one he favours most is that of the fly-catcher. Sometimes, however, he attaches himself to a flock of mynas. In such cases he flies to the van of the flock and squats on the ground, regardless of the fact that by so doing his beautiful forked tail gets dusty. As the mynas approach, snatching up grasshoppers, they put up a number of flying insects, and these the king crow secures on the wing. As soon as the last of the mynas has passed by the king crow again flies to the van and repeats the performance.