They form a league into which none are admitted except those who take the oath of allegiance; and, of course, to expose the weakness of the scientific doctrines of the time is equivalent to violating the oath of allegiance. Now, the man of science who has to earn his living by his science, has either to join the league or run the risk of starving. This explains how a small coterie of men has things very much its own way; how it can lay down the law without fear of contradiction. If a man does arise and declines to accept the fiats of this league, it is not difficult for the members to combine and tell the general public that that man is a foolish crank, who does not know what he is talking about; and the public naturally accepts this dictum.
The only scientific men who, as a cla.s.s, are characterised by humility are the meteorologists. I always feel sorry for the meteorologist.
He has to predict the weather, and every man is able to test the value of these predictions. The zoologist, on the other hand, does not predict anything. He merely lays down the law to people who know nothing of law. He a.s.sures the world that he can explain all organic phenomena, and the world believes him.
As a matter of fact, zoology is quite as backward as meteorology.
Those who do not wish to be deceived will do well to receive with caution all the zoological theories which at present hold the field.
Before many years have pa.s.sed all of them will have been modified beyond recognition. Most of them are already out of date.
There are doubtless good reasons for the colouring of both the grosbeak and the oriole; what these reasons are we know not. But as neither derives any benefit from the resemblance to the other, this _resemblance_ cannot have been effected by natural selection. Now, if the unknown forces, which cause the various organisms to take their varied colours and forms, sometimes produce two organisms of different families which closely resemble one another, and the organisms in question are so distributed that neither can derive the slightest advantage in the struggle for existence from the resemblance, there is no reason why similar resemblances should not be produced in the case of organisms which occupy the same areas of the earth. Thus it is quite possible that many so-called cases of mimicry are nothing of the kind.
The mere fact that one of the organisms in question may profit by the likeness is not sufficient to demonstrate that natural selection is responsible for the resemblance.
In this connection we must bear in mind that, according to the orthodox Darwinian theory, the resemblance must have come about gradually, and in its beginnings it cannot have profited the mimic _as a resemblance_.
So plastic are organisms, and so great is the number of living things in the earth, that it is not surprising that very similar forms should sometimes arise independently and in different parts of the globe.
Several instances of this fortuitous resemblance are cited in Beddard"s _Animal Colouration_; others are cited in _The Making of Species_ by Finn, and myself.
Perhaps the most striking case is that of a cuckoo found in New Zealand, known as _Eudynamis taitensis_. This is a near relative of the Indian koel, which bears remarkable resemblance to an American hawk (_Accipiter cooperi_). Writing of this cuckoo, Sir Walter Buller says: "Not only has our cuckoo the general contour of Cooper"s sparrow-hawk, but the tear-shaped markings on the underparts, and the arrow-head bars on the femoral plumes are exactly similar in both.
The resemblance is carried still further, in the beautifully-banded tail and marginal wing coverts, and likewise in the distribution of colours and markings on the sides of the neck. On turning to Mr.
Sharpe"s description of the young male of this species in his catalogue of the Accipitres in the British Museum, it will be seen how many of the terms employed apply equally to our Eudynamis, even to the general words, "deep brown above with a chocolate gloss, all the feathers of the upper surface broadly edged with rufous." ...
Beyond the general grouping of the colours there is nothing to remind us of our own Bush-hawk; and that there is no great protective resemblance is sufficiently manifested, from the fact that our cuckoo is persecuted on every possible occasion by the t.i.ts, which are timorous enough in the presence of a hawk."
These cases of chance resemblance should make us unwilling to talk about "mimicry," unless there is actual proof that one or other of the similar species benefits by the resemblance.
These cases, further, throw light on the origin of protective mimicry where it does exist.
Protective mimicry is usually said to have been brought about by the action of natural selection. This is not strictly accurate. Natural selection cannot cause two showy, dissimilar species to resemble one another; all it can do is to seize upon and perfect a resemblance that has been caused by the numerous factors that have co-operated to bring about all the diversity of organic life upon this earth.
_THE GREAT HIMALAYAN BARBET_
Barbets may be described as woodp.e.c.k.e.rs that are trying to become toucans. The most toucan-like of them all is the great Himalayan barbet (_Megalaema marshallorum_). Barbets are heavily-built birds of medium size, armed with formidable beaks, which they do not hesitate to use for aggressive purposes. As regards the nests they excavate, the eggs they lay, the pad that grows on the hocks of young birds, and their flight, they resemble their cousins the woodp.e.c.k.e.rs.
But they are fruit-eating birds, and not insectivorous; it is this that const.i.tutes the chief difference between them and the woodp.e.c.k.e.rs. Barbets are found throughout the tropical world. A number of species occur in India. The best known of these is the coppersmith, or crimson-breasted barbet (_Xantholaema haematocephala_), the little green fiend, gaudily painted about the head, which makes the hot weather in India seem worse than it really is by filling the welkin with the eternal monotone that resembles the sound of a hammer on a brazen vessel. Nearly as widely distributed are the various species of green barbet (_Thereiceryx_), whose call is scarcely less exasperating than that of the coppersmith, and may be described as the word _kutur_ shouted many times and usually preceded by a harsh laugh or cackle.
The finest of all the barbets are the _Megalaemas_. The great Himalayan barbet attains a length of 13 inches. There is no lack of colour in its plumage. The head and neck are a rich violet blue. The upper back is brownish olive with pale green longitudinal streaks. The lower back and the tail are bright green. The wings are green washed with blue, brown, and yellow. The upper breast is brown, and the remainder of the lower plumage, with the exception of a scarlet patch of feathers under the tail, is yellow with a blue band running along the middle line. This bright red patch under the tail is not uncommon in the bird world, and, curiously enough, it occurs in birds in no way related to one another and having little or nothing in common as regards habits.
It is seen in many bulbuls, robins, and woodp.e.c.k.e.rs, and in the pitta.
The existence of these red under tail-coverts in such diverse species can, I think, be explained only on the hypothesis that there is an inherent tendency to variation in this direction in many species.
A striking feature of the great Himalayan barbet is its ma.s.sive yellow bill, which is as large as that of some species of toucan. Although the bird displays a number of brilliant colours, it is not at all easy to distinguish from its leafy surroundings. It is one of those birds which are heard more often than seen.
Barbets are never so happy as when listening to their own voices.
Most birds sing and make a joyful noise only at the nesting season.
Not so the barbets; they call all the year round; even unfledged nestlings raise up the voices of infantile squeakiness.
The call of the great Himalayan barbet is very distinctive and easy to recognise, but is far from easy to portray in words. Jerdon described the call as a plaintive _pi-o_, _pi-o_. Hutton speaks of it as _hoo-hoo-hoo_. Scully syllabises it as _till-low_, _till-low_, _till-low_. Perhaps the best description of the note is that it is a mournful wailing, _pee-yu_, _pee-yu_, _pee-yu_. Some like the note, and consider it both striking and pleasant. Others would leave out the second adjective. Not a few regard the cry as the reverse of pleasant, and consider the bird a nuisance. As the bird is always on the move--its call at one moment ascends from the depths of a leafy valley and at the next emanates from a tree on the summit of some hill--the note does not get on one"s nerves as that of the coppersmith does. Whether men like its note or not, they all agree that it is plaintive and wailing. This, too, is the opinion of hillmen, some of whom declare that the souls of men who have suffered injuries in the Law Courts, and who have in consequence died of broken hearts, transmigrate into the great Himalayan barbets, and that is why these birds wail unceasingly _un-nee-ow_, _un-nee-ow_, which means "injustice, injustice." Obviously, the hillmen have not a high opinion of our Law Courts!
Himalayan barbets go about in small flocks, the members of which call out in chorus. They keep to the top of high trees, where, as has been said, they are not easily distinguished from the foliage. When perched they have a curious habit of wagging the tail from side to side, as a dog does, but with a jerky, mechanical movement. Their flight is noisy and undulating, like that of a woodp.e.c.k.e.r. They are said to subsist exclusively on fruit. This is an a.s.sertion which I feel inclined to challenge. In the first place, the species remains in the Himalayas all the year round, and fruit must be very scarce there in winter. Moreover, Mr. S. M. Townsend records that a barbet kept by him in captivity on one occasion devoured with gusto a dead mouse that had been placed in its cage. Barbets nest in cavities in the trunks of trees, which they themselves excavate with their powerful beaks, after the manner of woodp.e.c.k.e.rs. The entrance to the nest cavity is a neat circular hole in a tree at heights varying from 15 to 50 feet. Most birds which rear their broods in holes enter and leave the nest cavity fearlessly, even when they know they are being watched by human beings, evidently feeling that their eggs or young birds are securely hidden away in the heart of the tree. Not so the _Megalaema_. It is as nervous about the site of its nest as a lapwing is. Nevertheless, on one occasion, when the nest of a pair of the great Himalayan barbets was opened out and found to contain an egg and a young bird, which latter was left unmolested, the parent birds continued to feed the young one, notwithstanding the fact that the nest had been so greatly damaged. The eggs are white, like those of all species which habitually nest in holes.
_PART II_ _The Common Birds of the Nilgiris_
_THE COMMON BIRDS OF THE NILGIRIS_
The avifauna of the Nilgiris is considerably smaller than that of the Himalayas. This phenomenon is easily explained. The Nilgiris occupy a far less extensive area; they display less diversity of climate and scenery; the lofty peaks, covered with eternal snow, which form the most conspicuous feature of the Himalayan landscape, are wanting in the Nilgiris.
The birds found in and about a Nilgiri hill station differ in character from those of the plains distant but a score of miles.
Of the common birds of the plains of Madras, the only ones that are really abundant on the Nilgiris are the black crow, the sparrow, the white-eye, the Madras bulbul, the myna, the purple sunbird, the tailor-bird, the ashy wren-warbler, the rufous-backed shrike, the white-browed fantail flycatcher, the Indian pipit, the Indian skylark, the common kingfisher, the pied crested cuckoo, the scavenger vulture, the Pondicherry vulture, the white-backed vulture, the shikra, the spotted dove, and the little brown dove.
The distribution of the avifauna of mountainous countries is largely a matter of elevation. At the base of the Nilgiris all the plains birds of the neighbourhood occur, and most of them extend some way up the hillsides. The majority, however, do not ascend as high as 1000 feet.
At elevations of 3000 feet the avifauna of the hills is already markedly different from that of the plains; nevertheless many of the hill species do not descend to this level, at any rate in the summer.
It is, therefore, necessary, when speaking of a plains bird as occurring or not occurring on the hills, to define precisely what is intended by this expression.
That which follows is written for people who visit the Nilgiri hill stations in the hot weather, and therefore the birds described are those which occur at elevations of 5500 feet and upwards in the summer.
Those which visit the hills only in winter are either altogether ignored or given but the briefest mention.
This article does not deal exhaustively with the birds of the Nilgiris; it is merely a short account of the birds commonly seen in the higher regions of those hills during the summer months. To compile an exhaustive list would be easy. I refrain from doing so because a reader unacquainted with Indian ornithology would, if confronted by such a list, find it difficult to identify the common birds.
With this by way of introduction, I will proceed to describe the birds in question, dealing with them according to the cla.s.sification adopted in the standard book on Indian ornithology--the bird volumes of the "Fauna of British India" series.
THE CORVIDae OR CROW FAMILY
This family is not nearly so well represented on the Nilgiris as it is in the Himalayas. The only crow found on the Nilgiris is the Indian corby (_Corvus macrorhynchus_)--the large black crow familiar to persons living in the plains. He, alas, is plentiful in the various hill stations; but it is some consolation that the grey-necked _Corvus_ ceases from troubling those who seek the cool heights.
Like the grey-necked crow, the Indian tree-pie is not found at the Nilgiri hill stations--5000 feet appears to be the highest elevation to which he attains.
Of the t.i.ts only one species can be said to be common on the higher Nilgiris: this is the Indian grey t.i.t (_Parus atriceps_)--a striking little bird, smaller than a sparrow. The head, throat, and neck are black, and a strip of this hue runs down the middle of the abdomen.
The wings and tail are grey. The cheeks, the sides of the abdomen, and a patch on the back of the head are white. There is also a narrow white bar in the wing, and the grey tail is edged with white. The bird is found all over India, but is far more abundant on the hills than in the plains.
Another t.i.t which, I believe, does not ascend so high as Ootacamund, but which is not uncommon in the vicinity of c.o.o.noor is the southern yellow t.i.t (_Machlolophus haplonotus_). This bird is not, as its name would seem to imply, clothed from head to foot in yellow. Its prevailing hues are green and brown. The head, breast, and upper abdomen are bright yellow, except the crown, crest, a broad streak behind the eye, and a band running from the chin to the abdomen, which are black. It is impossible to mistake this sprightly little bird, which is like the English tom-t.i.t in shape. t.i.ts are arboreal in habits; they seldom descend to the ground. Sometimes they go about in small flocks. They are supposed to live chiefly on insects, but most of them feed on fruit and seeds also, and the grey t.i.t, alas, eats peas, among which it works sad havoc. The inhabitants of the Nilgiris call this last _Puttani kurivi_, which, I understand, means the pea-bird.
THE CRATEROPODIDae OR BABBLER FAMILY
This heterogeneous family is well represented in the Nilgiris.