Of the less ornamental drongos, the king crow is the best-known example. This bird is found in all parts of India, and occurs in Ceylon. Almost as widely distributed, but far less abundant, is the white-bellied drongo. This species may be met with in all parts of India save the Punjab. In the Western Province of Ceylon it is replaced by a drongo having less white in the plumage.

It is a moot question whether this last is to be looked upon as a race or a distinct species. Legge writes: “No bird in Ceylon is so puzzling as the present, and there is none to which I have given so much attention with a view to arriving at a satisfactory determination as to whether there are two species in the island or only one. I cannot come to any other conclusion than that there is but one, the opposing types of which are certainly somewhat distinct from one another, but which grade into each other in such a manner as to forbid their being rightly considered as distinct species; and I will leave it to others, who like to take the matter up for investigation, to prove whether my conclusions are erroneous or not.” Oates has since constituted the birds which have less white on the lower parts a distinct species, which he calls the white-vented drongo (Dicrurus leucopygialis). He admits that the amount of white on this form and on the white-bellied species (Dicrurus cÆrulescens) is variable, and that a bird is occasionally met with which might, as regards this character, be assigned indifferently to one or the other species, but, says he, the colour of the throat and breast will, in these cases, be a safe guide in identification. The parts in question are grey in the white-bellied species and dark brown in the white-vented form. It seems to me that a slight difference in the colouring of the feathers of the throat is not a very safe foundation on which to establish a new species. However, this piece of species-splitting need not worry the Anglo-Indian, for the white-vented form is found only in Ceylon. All drongos with white underparts that occur in India are Dicrurus cÆrulescens. This bird is not common in Madras; I observed it but twice during eighteen months’ residence in that city. It is in shape exactly like the common king crow, and possesses the characteristic forked tail, but it is a smaller bird, being nine and a half inches in length, and therefore shorter by fully three inches than the black drongo. Its upper plumage is deep indigo; the throat and breast are grey; all the remainder of the lower plumage is white. Its habits are very much like those of the king crow, but it is less addicted to the open country, seeming to prefer well-wooded localities. I have never seen the Dhouli, or white-bellied drongo, perched on anything but a branch of a tree. It almost always catches its insect prey upon the wing, after the manner of a fly-catcher. Jerdon, however, states that he once saw it descend to the ground for an insect.

As a singer it is far superior to the king crow. In addition to the harsh notes of that species it produces many melodious sounds. Tickell describes its song as “a wild, mellow whistle pleasingly modulated.” It was the voice of the bird that first attracted my notice. Some eight years ago, when camping in the Fyzabad District, I heard a very pleasing but unknown song. Tracking this to the mango tope whence it issued, I discovered that the author was a white-bellied king crow. Last winter a member of this species favoured me with a fine histrionic performance. I was sitting outside my tent one afternoon, when I heard above me a harsh note that was not quite like that of the king crow. Looking up, I observed, perched on a bare branch at the summit of the tree, a white-bellied drongo. Then, as if for my especial benefit, he began to imitate the call of the shikra; he followed this up by a very fair reproduction of some of the cries of a tree-pie. Having accomplished this, he made, first his bow, then his exit. I was much interested in the performance, since an allied species, the bhimraj, is not only one of the best songsters in the East, but a mimic second only to the wonderful mocking-bird of South America.

The white-bellied drongo is so rare in the peninsula of India that not one of our ornithologists has given us anything like a full account of its habits, and no one appears to have discovered the nest in India. Fortunately, it is very common in Ceylon, so that Legge has been able to give some interesting details regarding its habits. We must bear in mind that Legge includes both the white-bellied varieties under one species. If we divide them into two, the question arises to which do his various observations apply? The reply is to either or both, for Legge was not able to detect any differences between them, except that perhaps the white-vented variety has a more powerful voice. He writes: “It is occasionally, when there is abundance of food about, a sociable species, as many as three or four collecting on one tree, and carrying on a vigorous warfare against the surrounding insect world.” Like the king crow, it is an early riser and a late rooster. It is a great chaser of crows, and of any creature that dares to intrude into the tree in which its nest is placed. Needless to say that it detests owls. Says Legge: “The white-bellied king crow never fails to collect all the small birds in the vicinity whenever it discovers one of these nocturnal offenders, chasing it through the wood until it escapes into some thicket which baffles the pursuit of its persecutors.” But why does he call owls “nocturnal offenders”? Wherein lies their offence? So far as I can see, the only crime that owls commit is in being owls. The creatures they prey upon have reason for disliking them. But owls do not attack ornithologists. Why, then, should these gentry call them hard names?

The nesting habits of both the white-bellied and the white-vented drongos are very similar to those of the common king crow. Legge describes the nest as a shallow cup, almost invariably built at the horizontal fork of the branch of a large tree at a considerable height from the ground, sometimes as much as forty feet. The eggs seem to vary as greatly in appearance as do those of the common king crow.

Since the white-bellied drongo appears to be quite as pugnacious as its black cousin, and to have almost identical habits, it is strange that it should be so uncommon in India. As we have seen, its distribution is wide, so that it seems able to adapt itself to various kinds of climate. Nevertheless, it is common nowhere in India. What is the cause that keeps down its numbers? Naturalists are wont to talk airily about natural selection causing a species to be numerous or the reverse, but unless they can show precisely how natural selection acts they explain nothing. Those who write books on natural history convey the impression that it is the birds and beasts of prey that keep down the numbers of the smaller fry. As a matter of fact, predaceous creatures seem to exercise but little influence on the numbers of their quarry. There are hidden causes at work of which we know almost nothing. Damp and small parasites are probably far more powerful checks on multiplication than predaceous creatures. It would seem that there is something in the constitution of the white-bellied drongo which enables it to outnumber the king crows proper in Ceylon, but which prevents it from becoming abundant in the peninsula of India. What this something is we have yet to discover. We really know very little of the nature of that mysterious force with which naturalists love to conjure, and which Darwin named Natural Selection. We write it with a capital N and a capital S, and then imagine that we have explained everything.

“Twinkle, twinkle, little star,

Now we all know what you are.”