The Parents' Review

A Monthly Magazine of Home-Training and Culture

Songs and Species.

Close together, with only the width between them of a quarry road and its two walls, overhung by the boughs of the coppice trees they perch in, sing a Garden Warbler and a Blackcap Warbler. It is a rare hearing.

Now sounds the one long strophe, made up of rapid, bubbling, even notes, each light and limpid as the spray of water showered from a fall, and as fleeting; now, again, as that ceases, the opposing straining, too like for words to do more than maul the differences; a strophe, yes! of rapid rippling notes, yet shorter, more resonantly full and sharp, more flutey-tones, more loud-and-soft combined. Then again; for they sing antiphonally, clearly listening each to each, and maybe roused and irritated to response.

But this will not last. Once in a while the birds may even be seen on the same beechen bough, the Blackcap hopping inquisitively closer to the Garden Warbler, till this flies off. But such meetings seem accidental, prolonged for a few moments only from curiosity; then a natural aversion, born perhaps of their great similarity, asserts itself, and the birds drift apart, to establish stations out of hearing the one of the other.

These two species of birds are practically the same size, the same weight, have much the same habits, take the same food, make the same kind of nests, lay the same number of eggs, sing so much the same song that it needs a practised ear to determine them. Yet they are different, with a difference that shows to the human being in song, slightly, and in colour of head, clearly. Whatever other differences there may be, they and these are sufficient to hold the two apart. An incommunicable quality lies like a gulf between them. They will not inter-breed. They are two species; aliens, foreign to each other.

Nor are these two the sole similar members of the avian world that live contiguously, yet dwell apart in a careful avoidance. There are not only numbers of other bird-species nesting around--a whole gamut of forms readily distinguishable one from another, but there are one or two others so intimately connected with these that they are often confused.

The Whitethroat, for instance, is so similar to these that it seems of old to have shared in our parts a common name with the Garden Warbler, while the scientists call the three by the same generic name. It is similar in size and colour, its nest is very similar, its voice is appreciably similar, so that the Whitethroat's best strain is confusingly like the Garden Warbler's worst. Then the Whitethroat, not avoiding, but rather courting comparison, often camps out for the summer on the very ground occupied by the Garden Warbler, and acting as his double, bold when he is shy, comes to the front when he retires. To the utter confusion of the generally obtuse observer, he often appears to dissemble, and to act the part of the Garden Warbler.

But even here, similar and close as these two forms are, there apparently exists no confusion of individuality between themselves. Alike and near, they are quite apart. Mimic and mocker as the Whitethroat occasionally is, his fundamental differences of race are maintained. There seems to be no tendency to inter-breed.

And so we might go on, running up the gamut of kinds,--the Lesser Whitethroat next, so like again; then other Warblers,--step by step, through all that class of closely-connected dun-coloured birds of migratory habit, whose identity it took years of acute observation by noted naturalists to establish, to clear up the confusion amongst them, and finally to sever them, and fix them as species.

"Every winged fowl after its kind," as the old Book hath it. A marvellous thing indeed, this kindship, in the kingdom of birds! Not seven species now, such as tided the fowls of the air over the flood-time in the ark, we are told, but seven hundred times seven and more. Nigh seven times ten of different kinds nesting in this one little parish, side by side, yet all of them preserving their boundaries of race; singing for and mating only with their own; no Buzzard coupling with Kestrel, no Crow with Rook, no Waterhen with Coot, no Throstle with Blackbird. All, even when so closely allied that the differences may baffle us, keeping strictly to their own "kinds."

Man experiences nothing comparable to it. Ancient, or savage man, indeed preserving more distinctions of race; and with tribal instincts strong, sought to live apart from a kindred, though contiguous, people. Laws, written and un-written, fostered division, and forbad marriage with the stranger. The closer the ties of race, the nearer the dwelling place, the more fiercely often did the instinct of division, through hatred and war, burn. But the effort after division proved useless for the race: in the genus homo, there remains but one species. Man, indeed, now rarely lives side by side or equality with another race than his own. If he does, there is at once a struggle for ascendancy, and when one is master of the other--supposing intelligences to be pretty equal (and if not, the inferior dies out)--intermarriage begins and distinction ends. So that he knows nothing of that art of living amongst many others formed on the same ground plan as himself, from whom, because of certain racial differences, he religiously keeps himself apart. Separatism as a species is unknown to him; the feeling exists only as a casual impulse in the individual. Try as we may, therefore, to understand that amicable aloofness among birds that holds species from species, there is yet nothing comparable to it in our range of life.

There is no doubt that birds have made room for themselves, so to speak, by the cultivation of those differences that make species. They can exist in greater numbers, because they play different parts in the great field of nature. The Dipper's fledgling, when it leaves the nest, hardly understands as yet that its food is to be sought for in the water; but having learnt this from its parents' actions, it enters at once into the peculiar domain of its species, and fears no competition, though food be scarce, from any other Ousel. The young Creeper, scrambling from its nest, hangs itself up on the bark at once, and never attempts to take food from the green leaves where so many other birds feed. Every species has its own habit, its own nook in the cupboard of mother Nature; and by preserving its individualities, it saves its own life, and that of the species.

This is easy to understand upon the broad lines of difference; we can see perfectly how it acts between, for instance, Titmice and Tree-creeper, Dipper and Warblers. It is only when the dim, blurred lines of similar habits in similar species come in, that the mystery of the matter strikes us. Six kinds of Warblers nesting on one woodland mile alone; three kinds of Terns nesting on one short stretch of sand-dune! How are the differences preserved? How did they come to exist? How came the Common and the Arctic Tern to be two species, when, as a proof of difference, the tarsus of the dead bird has to be measured?

How is the unwritten law of kind fulfilled, after--say--some new-invented method or habit puts the first sundering line between bird and bird? We know that Rooks resent a pair of their kind breaking loose from the colony, and will punish the procedure by destruction of the nest. Would something of the kind occur, if a pair of Sandwich Terns crossed to the Common Tern's colony a furlong off, and laid eggs there, or began--not only to fish side by side with the stranger (for this often happens) but to nob-nob familiarly with him? We must suppose--though it is difficult to see where toleration would end and scruple begin--there would then be war to the beak, and that that active intolerance or persecution would be set up which is no doubt the safeguard of species.

For only the utmost conservatism of habit, the most jealous regard of racial marks, could preserve these sharp lines of demarcation amidst so much similarity. In spite of a certain amount of amicable tolerance, which permits species like Green and Golden Plovers, Bullfinch and Redpole, and the different Titmice, to associate by flocks in winter, there must be rigid rules of division, never crossed. I have seen the Great Titmouse "go for" a Blue Titmouse that--accidentally, no doubt--approached too closely, in a mixed winter company, a hen of his own kind.

And species-jealousy, as well as sex-jealousy, must be enormously increased at breeding-time, when each pair falls apart to nest. It is the crucial period for race or species preservation. Each bird pairs with its kind, and seeks the most individual of its kind to pair with. All the access of energy, special to the period, goes towards differentiation. The badge of species, in feather and song, is then the most vividly defined. Colour and marking that subsided in winter, glow again into sudden brilliance; voices, lost in winter, peal forth again, in the special refrain of the tribe. Wherever its pre-eminence lies, each bird puts that point of pre-eminence prominently forth. When choosing-time comes, there has to be no mistake. And there can be consequently no intermarriages between species in a natural state, no tolerance of any other charms than those belonging to the one kind alone. Though nearly related species will breed in confinement, when instinct is baulked, such an anomaly is more than the exception in nature. Odd birds of either sex, failing to find a mate of their own race, drift back a thousand miles to their winter homes, unmarried. This fact, suspected before, is proved by the observations of Herr [Heinrich] Gätke. No Willow Warbler mates with Chiff-chaff, like as they are, except in song; no Wood Warbler with Willow Warbler; no Garden Warbler with Wood Warbler. These little brown birds all know themselves and their cousin-germains to finest feature; there is no confusion with them, no breaking the law of kind, no crossing the sharp dividing line of species.

Thus while colours brighten and voices strengthen for the breeding-time, how keenly must the faculties behind those flags of species begin to work! What powers of discrimination and perception must the little birds possess! What keenness of eye and ear, particular of ear! Those two voices of Warblers, sounding now antiphonally, rich and full alike to us, are no doubt to themselves and their hens totally different. No shy Garden Warbler hen, creeping new-come about the foliage, would draw to that ambush where the Blackcap sounds out his mellifluous song. Rather would she avoid it in fear, and pass on, till the voice of her own species striking her ear, she would move into the magic circle of song, and reveal herself to the songster.

And probably the reason why all our greater songsters are dun and brown, is because the strongest force of their racial instinct is directed to the exercise of the vocal organs. All the excess of vitality, that comes to them then, is spent on the voice. Voice is to them the hall-mark of race; by it they assert themselves, by it they select their mates. The chiff-chaff's note rings as plain (even to us) as if it called "It is I, it is I" though his little body cannot be told, at a glimpse, from his cousins; and he goes on calling it all the time, for fear of mistakes. It is his great characteristic. The gayer-plumaged birds, on the other hand, such as Titmice, have indifferent voices, and--unlike the songsters that pour forth at breeding-time an almost incessant and amazing flow of melody--use their breeding note but little. They choose by sight and colour, and throw the force of their exuberant vitality into that. The Redstart, indeed, most brilliant of plumage, does sing, though his voice is not sweet; but, beautiful and most nervous, he needs a song as a signal in the ambush he seeks after migration; and when his hen has come, he gives it mostly up, and shows off his colours in antics before her. So that if a hen Redstart has two rivals to choose from, the rivalry seems (judging from observation) to lie in colour and not in song: she chooses by eye and not by ear.

Thus, these two brown Warblers, that linger together on each side of the road, singing so exquisitely in turns, belong to races that choose by ear, and not by eye. They value sound more than colour. That aesthetic sense that belongs to the period of passion, is directed to the voice instead of feather. They are musicians; they know by long ancestral practice how to attune their burning sense of species, of separation, of desire after their kind, to exquisite melody. No wonder that, though but dimly followed, that melody delights us!

Proofread by LNL, June 2020