Part 12

The wryneck is not singular among birds in uttering its note only at certain seasons of the year. Very few of the song birds pour forth their melody all the year round. This fact bears powerful testimony to the view I have frequently enunciated as to the nature of birds’ song. There is nothing conversational in it, nothing in the nature of language; it is merely the expression of superabundant vitality which fills most birds at certain seasons of the year.

Like very many other migrants, the wryneck does not appear to be powerful on the wing. Its flight has been well described as “precipitate and awkward.”

The wryneck derives its name from a curious habit it has of twisting its neck as it seeks for insects on a tree-trunk or mound.

Wrynecks are very rarely seen in cages or aviaries, probably because they are not songsters and because their habits are not such as to render them attractive in an aviary. Nevertheless, wrynecks thrive in captivity. Bishop Stanley records an instance of a wryneck which “lived for a year and a half in a cage, and never appeared to show impatience during its confinement; it was observed always to take its food by throwing out its long tongue.”

During the winter the wryneck seems to visit all parts of India, except possibly the Malabar coast, and it is sufficiently common in South India to have a Tamil name—Moda nulingadu.

The wryneck breeds neither in the plains of India nor, I believe, in the Himalayas, but its nest has been recorded in Kashmir. It busies itself with parental duties in the summer—in May and June in England—laying its glossy white eggs in a hollow in a tree. Unlike the woodpecker the wryneck does not hollow out its hole for itself. It is sensible enough not to undertake that which can be equally well done by others. In this respect, as in so many others, it differs from the woodpeckers proper.

XXII GREEN PIGEONS

Green birds are comparatively few in number, but nearly all of those that do exist are very beautiful objects. Green is a colour which is rarely found alone in birds. The fowls of the air of which the plumage is mainly green almost invariably display patches of other colour. In the familiar green parrots red, pink, blue, and black occur; the green coppersmith flaunts the most gaudy hues of red, crimson, and yellow; the emerald merops adorns itself with gold and turquoise ornaments; while green pigeons are birds which display the whole spectrum of colours, each in a subdued form. In the common Indian species the forehead is greenish yellow; the nape and sides of the head French grey; the chin and neck are old gold shading off into olive; the body is greenish olive; the shoulder is washed with lilac. The primary wing feathers are dark grey, while the secondaries are similarly coloured, but have pale yellow tips. The tail is slate-coloured, becoming greenish yellow at the base. The feathers under the tail are a dark claret colour with creamy bars. The lower parts are slate-coloured tinged with green, save for the feathers of the thigh, which are canary yellow. The legs are orange yellow. The eye is blue, with an outer ring of carmine. Yet, notwithstanding all this show of colour, there is nothing gaudy about the green pigeon. Every tint is most delicately laid on, and each hue blends into the surrounding ones in a truly exquisite fashion, so that it is no exaggeration to call the green pigeon a vision of perfect loveliness.

In the unlikely event of any one taking the trouble to compare the above description with those given in the fauna of British India for Crocopus phœnicopterus (the Bengal green pigeon) and C. chlorogaster (the Southern green pigeon), that person will observe that it does not tally exactly with either of them. Nevertheless, my description is taken from a specimen shot by me in the Basti district of the United Provinces. The fact of the matter is that in places where the Bengal form meets the southern species the two interbreed, as, I believe, do all, or nearly all, allied species at the point of junction. And, in such cases, the hybrid birds appear to be perfectly fertile and to thrive equally with the parent species; neither of which would be the case were facts in accordance with the Wallaceian theory. But, as we shall see later, green pigeons seem to lay themselves out to destroy the biological orthodoxy of to-day.

Green pigeons appear to live exclusively on fruit. They go about in small flocks, seeking out trees of which the fruit is ripe; when they hit upon such a tree they behave as if they were schoolboys let loose in a tuck shop!

The Hindustani name for the green pigeon is Harrial. The natives, or at any rate some of them, assert that the bird never descends to the ground, because when its foot touches the earth the bird loses a pound in weight, in other words, shrivels up into nothingness! If asked how it drinks, they will reply that it settles on a reed which bends with its weight, so that it is able to partake of the water beneath without touching the earth. In the absence of a conveniently situated reed, the green pigeon overcomes the difficulty by carrying a twig in its feet. It would be interesting to discover the origin of this story, which is on a par with that which asserts that the red-wattled lapwing (Sarcogrammus indicus) sleeps on its back with its legs in the air, in order to be ready to catch the sky on its feet if ever this should fall! As a matter of fact green pigeons are very arboreal in their habits. I do not remember ever having seen one of them on the ground.

The note of the green pigeons is not a coo, but a pleasant whistle. The birds are sometimes caged on account of their song. But they are uninteresting pets. In captivity they soon lose their beauty, because they are so gluttonous as to smear the head and neck with whatever fruit be given them to eat.

Green pigeons are said to be far less obtrusive in their courtship than the majority of their kind. The male does not puff himself out after the manner of other cock pigeons, but is content to bow before his lady love and in this attitude move his expanded tail up and down.

There are few birds that assimilate so closely to their surroundings as green pigeons. Fifty of them may be perched in a pipal tree, and a man on the look-out for them may fail to detect a single individual until one of the birds moves. They are thus excellent examples of protectively coloured birds. Their green livery undoubtedly affords them a certain amount of protection, and so may perhaps be considered a product of natural selection. Be this as it may, a consideration of the details of the colouring of their plumage shows that many of these, as, for example, the lilac on the wing, are quite unnecessary for the concealment of the bird. The eastern and the southern species which occur together in certain places and the hybrids produced by the interbreeding of these are all equally difficult to distinguish from the surrounding leaves, notwithstanding the fact that their plumage differs in details, e.g. the breast and the abdomen are greenish yellow in the southern and ashy-grey in the eastern form, while there is green in the forehead and tail of the latter, but not of the former. Thus we have two species of green pigeon, of which at least one has not originated by natural selection. Facts such as these, however, do not prevent Dr. Wallace, Sir E. Ray Lankester, and Professor Poulton continually proclaiming from the housetops that every existing species owes its origin to natural selection and nothing but natural selection!

There are several genera of green pigeons, and all of them are characterised by short legs and broad toes. These are adaptations to the arboreal habit, in the formation of which natural selection has, in all probability, played an important part. The habits of all the genera are identical. They, one and all, build the rough-and-ready shakedowns which do duty for nests amongst the Columbidæ. All lay the inevitable two white eggs. Yet the sexes of the genus Crocopus are alike in external appearance, while those of the genera Osmosteros, Sphenocercus, and Treron exhibit considerable dimorphism. Again in the genus Butreron the sexual differences displayed are inconsiderable. These facts, of themselves, are quite sufficient to disprove the theory that sexual dimorphism in birds is due to the hen’s greater need of protection. Cock green pigeons assimilate so well to their leafy environment that there cannot possibly be any necessity for their wives to be differently dressed. Further, it is worthy of note that the most flourishing of the genera of green pigeons is that in which the sexes dress alike.

XXIII BULBULS’ NESTS—I

In May, 1911, a pair of red-whiskered bulbuls (Otocompsa emeria) took up their residence in my verandah at Fyzabad, that is to say, they spent the greater part of the day there in constructing a nest in a croton plant. The nest of the bulbul is a shallow cup, formed of bast, roots, twigs, and grass, loosely worked together. Sometimes dead leaves, pieces of rag and other oddments are woven into the fabric of the nest. The pair of bulbuls of which I write did not, however, indulge in any of these luxuries; they were content with a rudely constructed nursery. When the nest was nearly complete the owners deserted it. Why they acted thus I have not been able to discover.

The bulbuls absented themselves for a few days. When they returned they frequented another portion of the verandah, and their fussiness betrayed the fact that they were working at another nest. Several days passed before I found time to look for their nest, and I then discovered it in an aralia plant growing in the verandah, in a large pot placed at the right-hand side of one of the doors leading into my office room. The site chosen was the more remarkable in that it was within ten feet of the carpet on which the chaprassis sit when not engaged in active work. This nest was of even rougher design than the first one, and was equally devoid of decoration. So carelessly had it been constructed that, to use a nautical expression, it had a distinct list. I found in the nest three pinkish eggs, mottled and blotched with purplish red. They had been laid some time before I first saw them. This was demonstrated by the reluctance of the hen to leave the nest when I approached. Among birds the parental instinct increases as incubation proceeds. On one occasion the bird sitting on the nest in question allowed me to stroke its tail. This organ projects upwards like a semaphore, the nest not being sufficiently large to accommodate it.

It was not until the 15th July that I had leisure to watch these bulbuls closely. Up to that time I had merely noticed that both birds incubate, and that both sexes, and not the cock alone, as some writers assert, have the red “whiskers,” or feathers, on the cheeks.

The weather being warm, it was not necessary for the birds to sit continuously, and the eggs were frequently left for ten minutes or longer at a time. On the morning of the 15th July, I found that two of the young birds had hatched out. Both parents were feeding them.

Birds are creatures of habit. Each parent bulbul had its own way of approaching the nest and of perching when tending the nestlings, so that, although I was not able to say for certain which of the pair was the cock and which the hen, I could distinguish one individual from the other. For brevity I will call them A and B, respectively.

Both birds, before flying to the nest, used to alight on the stem of a palm standing in the verandah. From this point their manœuvres differed. Individual A invariably flew to a stout vertical branch of the aralia, remained there for a second or two, flitted to a second vertical branch, and from thence hopped on to the edge of the nest, so that its face when there pointed to the east. This individual always showed itself the bolder spirit of the two. The other bird, B, used to fly from the palm to a slender leafy branch of the aralia, and thus cause considerable commotion among the leaves; from thence it jumped on to the edge of the nest, where it perched with its face pointing to the north. The modus operandi of A was the superior. The verandah faces the east, so that when A wished to leave the nest, it had but to jump across it into the space beyond, and then wing its way ahead, while B had to turn round before it could fly off. The neatness and address with which A used to leap across the nest into the air baffles description.

The 16th July fell on a Sunday. I therefore determined to devote some hours to studying the ways of those bulbuls at the nest. Every naturalist has his own method of prying into the ways of the fowls of the air or the beasts of the field. Some expose themselves to the Indian sun at midday in May, others will squat for hours in feverish swamps. People who do these things are worthy of all praise. I prefer less heroic methods. Accordingly, I had the pot containing the nest-bearing plant moved a distance of rather less than a yard, so that it stood in the middle of the door-way. I then had an easy chair placed in the office room at a distance of some four feet from the nest. Finally, I removed such of the leaves as tended to obstruct my view. Thus, I was able to watch the bulbuls through the chik in comfort, reclining in the easy chair.

Both parent birds were present when the plant was being moved. They looked rather alarmed, but raised no outcry. They did not seem eager to approach the nest after the position of the aralia had been changed. Evidently they did not understand the meaning of what they had seen. Eventually bulbul A summoned sufficient courage to visit the nest, and must have been highly gratified to find the two youngsters and the egg safe. While perching on the nest it kept its eye on me, having espied me, notwithstanding the fact that there was a chik between me and it. While eyeing me it cocked its head on one side and half opened its bill. The opening of the bill is an expression of anger. The bulbul’s crest was also folded back, but this does not necessarily denote anger. The crest invariably assumes this attitude when the bulbul is incubating, or brooding, or feeding its young. It was some time before bulbul B could bring itself to visit the nest. It made at least six abortive attempts before it reached the edge of the nest, and then perched only for a second before flying off with every sign of trepidation. And for the whole of that day it showed itself nervous, whereas A soon came quite boldly to the nest. The difference in temperament between the two birds was most marked.

The parent birds did not come to the nest with the bill very full. They were usually content to bring one succulent grub or insect at a time.

In the earliest stages of their existence bulbul nestlings are so small that one caterpillar satisfies their hunger completely for some little time. So that it often happened that one of the parents arrived with food for which neither of the young birds was ready. Under such circumstances, the parent, after trying to force the food into the mouth of each nestling, remained on the rim of the nest waiting patiently until one of the youngsters lifted up its head for food. The baby bulbuls did not display at this early stage of their existence that eagerness for food, amounting almost to greediness, that characterises nestlings when they grow a little older.

On arrival with food the adult bird invariably uttered a couple of tinkling notes as if to inform its offspring that it had brought food. No sound emanated from the young birds during the first two or three days of their existence. When it had disposed of the food it had brought, the parent bird usually looked after the sanitation of the nest by picking up and eating the excreta. The parent birds did not appear ever to bring water to the nestlings. The succulent food probably supplies the requisite moisture. About midday on the 16th July the third young bird hatched out. The egg was intact at 10 a.m., but by a few minutes after midday the youngster had emerged, and half the shell was still in the nest. Thus the latest arrival made his appearance at least twenty-eight hours after either of his brethren.

I watched carefully in order to ascertain how the parent birds got rid of the egg-shell. Presently bulbul A came to the nest with food. When it had disposed of this, it began pecking in the nest, and appeared to be eating up the shell, but in reality it was cleaning the nest. After being thus engaged for a couple of minutes it flew off, carrying the half egg-shell in its beak. It flew to a distance with this, so that I did not see what became of it. This explains why broken egg-shells are seldom found lying on the ground below a nest. On the following day I placed a small piece of paper in the nest. This was carried off by the first parent bird to visit the nest, but not before the bird had fed its young. Shortly afterwards I placed a sheet of thick paper over the top of the nest so as to completely cover it. This nonplussed both parents. They made no attempt to insert their heads underneath it, but hopped about near the nest looking very disconsolate. I therefore removed the obstruction.