[27] Sexual, as I now believe. A recent lucky glimpse of nightingale courtship has assured me that I have not unconsciously exaggerated. Indeed, the ruddy glow of the broadly fanned tail, caught in the last rays of the descending sun, could hardly be exaggerated. But the colour was on all the rectrices. They alone, I think, are the patch, the star.
No good illustration, that I know of, exists of the nightingale; none, at least, which at all resembles the bird as I have seen it, either sitting, hopping, flying, singing, or silent. In natural history books, after we have been solemnly told that the male alone sings, that his song constitutes his courtship, and that, therefore, both the "she" and the "melancholy" of poets are incorrect, we are generally presented with a gaunt, scraggy-looking creature, having a woe-begone gaze which is fixed upon the moon, towards which its neck and whole body seem drawn out, as by some attractive force. This is the nightingale of convention, but when I have seen it, it has always looked the pleasingly plump, cheerful, little, brisk, active body that it really is, and when it sang it was without any "pose," in a hunched-up, careless-looking attitude, which had almost a feathered podginess about it. The legs were bent, the feathers of the ventral surface touching, or almost touching, the twig of perch, the head inclining forward at an easy angle—a cosy, homely, happy, contented appearance. I have watched one singing thus for some time. Not once did he rear himself up, so as to become long, thin, and tubey—tubby he was rather, and had not the faintest resemblance to a horrible, man-made, first-prize-for-deformity canary bird. Just in the same way, too, he will often sing on the ground, looking as homely and rotund as can be. True it is, as the natural history books tell us, that no one familiar with the bird and its habits would think of calling it or its song melancholy; therefore (as these never add), remembering Milton's famous line, let us be thankful that he as well as some other poets were not familiar with it. There has long been a nightingale of poetry and literature, grown out of its own song but having little to do with the real bird, which no one except strict scientists—and a literary critic or two—would wish to do away with.
With regard to the nest-building habits of the nightingale, I have only the space to say that, as in the case of the blackbird, the female alone collects and arranges the materials, being attended upon whilst she does so—though, perhaps, not quite so closely—by the male. One should be cautious, however, in concluding that such is always the case either with this or other birds, for I have watched, for some time, one of a pair of long-tailed tits bringing feathers to the nest, whilst the other kept near about, with nothing in its bill. Yet ordinarily both sexes work together in a most exemplary way. Nothing can look prettier than these little, soft, pinky, feathery things, as they creep mousily into their soft, little purse of a nest; nothing can look prettier than they do as they sit within it, pulling, pushing, ramming, patting, and arranging; finally, nothing can look prettier than they look as they again creep out of it and fly away. Their perpetual feat of turning round in the nest without dislocating the tail, is also one of those few earthly things in the seeing of which one cannot weary.
I have often tried to watch these little birds collecting, so as to see them actually find and fly away with the materials for the nest. This, however, I found more difficult than I had expected. Every time I saw them fly out of their nest, but in spite of stealthy following, I generally lost them soon after they had entered a plantation close to where, in a fir-hedge, it was. All I could be sure of was that they flew about in different directions, sometimes into tall fir-trees, sometimes into low tangles and bushes, sometimes, too, across the road again and into different parts of the fir-hedge. "They keep, for the most part, together, and whenever they are near enough I hear their soft, subdued little 'chit chit.' As lichen, which is what they are now principally collecting, is everywhere about on the trunks of trees, etc., it would seem as though even a minute would be a long time for them to take in getting a piece and returning with it, if they took it at random; and the inference appears to be that they exercise choice and selection, and return each time from the nest with a definite idea of the kind of bit they want next."
I will here quote, from my notes, an observation I made on the way these little birds roost at night, which may, perhaps, be of interest. "On my way back I noticed some object which I took to be a dead bird, in a tall, straggling brier-bush that formed a kind of bower, inside which one could stand up. Thinking that this bird might have been transfixed by a shrike, I came right under it, and, pulling down the branches with my stick, to my astonishment the object separated and became four little, fluttering, 'chittering,' long-tailed tits that had been sitting wedged close together. I stood perfectly still, and after they had 'chit, chitted' a little, and made a few little hops about the bush, two of them came back from different directions to just the same place, snoozled up to each other and were settled again for the night. Very soon, a third hopped on to the two backs and pressed himself down between them, taking no denial, and, indeed, not receiving any. The fourth remained a little longer apart, perhaps for ten minutes, during all which time I stood without a motion, leaning on my stick, and had, at last, the satisfaction to see him come perching down towards the bough, then perch on the three backs just as the third had done on the two, and squeeze himself in amongst them so that two were on one side of him and one on the other. All four now sat closely pressed together, three tails projecting on one side of the twig, and the fourth on the other. I sat down in the bush and made this entry, whilst the birdies—surely the prettiest little ones, almost, in the world—went to sleep.
"Next night, at about six, I took up my position in the same place, and waited. After I had sat silently for a few minutes, I saw a pair of the tits creeping softly about through the bushes adjacent, uttering the little chitter in a very subdued tone. One was soon in the actual bush, but crept out of it again and went away with the other. In another four or five minutes, however, they both return, this time coming more quickly and directly to the bush, when soon getting, from opposite sides, to very much the same part of it as before, they sidle to each other along the particular twig and then squeeze and press together so tightly that their outline on the inner side is quite lost, like that of a double cherry. Thus pressed and wedged, each little bird preens itself, the two little heads moving about and seeming to belong to one quite round body, having one tail—for their two tails are pressed, for their whole length, together. When their heads turn inwards the little birds appear to be caressing each other, and they must, I think, sometimes catch hold of each other's feathers, but it is all part, or intended to be part, of the process of preening themselves. This close pressing seems to be a pleasure in itself, independently of the result of warmth, for sometimes they will come unstuck, as it were, and move a little away from each other along the twig, in order to press and squeeze again. For a little, then, their tails may be separate, but soon they rejoin, and, the heads being now quiet—for they are going to sleep—and tucked closely in amongst the feathers of the breast, their outlines, never very salient, are entirely lost, and the two birds have become one perfectly globular one, without a head and with a long tail. Thus two of these long-tailed tits have returned again to roost in the same place, but the other pair do not come to the bush."
It is interesting to watch sand-martins building their nests, or, rather, excavating the tunnels in which they will afterwards be built. To see one enter one of these whilst it is yet but a few inches long, and then to see the dust powdering out at the aperture, as from the mouth of an ensconced cannon, is pretty. The sand is scratched out backwards with the feet, but the bird also uses its bill as a pickaxe, often making a series of rapid little blows with it, almost like a woodpecker, the wings, which quite cover the body, quivering at the same time. Both sexes work at the hole, and both often fly together to it, one remaining clinging at the edge whilst the other scratches out the sand from inside. I have seen one sitting just in the embrasure, quietly regarding the outer world and, thus, impeding the entrance of his partner, who at last squeezed by him with great difficulty. Sometimes three or four will descend upon the same hole and cling there without quarrelling; but once I saw a bird in a hole attacked by another, who flew suddenly down upon it with a little twittering scream.
Though each pair of birds excavate their own tunnel, yet the whole community, or, at any rate, a large proportion of it, will sometimes work together, sweeping on to the pit's face in a body, clinging there and burrowing, with a constant twittering, then darting off silently in a cloud and sailing and circling round in the pit's amphitheatre, making, when the sky is blue and the sun bright, a warm and delicious picture such as the Greeks must have loved to gaze on.
As each bird, however, only works at his own and his partner's hole, it is evident that this kind of social working is not the same as that of ants or bees and other such insect communities, though it has something of that appearance. Sometimes, for a short time, all the birds will keep fluttering round in small circles that only extend a little beyond the face of the cliff, not rising to a greater height than their own tunnels in it, which they almost touch each time, as they come round. They look like eddies in a stream beneath the bank, but are not so silent, for all are twittering excitedly. This is an interesting thing to see, a kind of aerial manœuvres the special cause of which, if there be one, is not obvious.
But we will suppose that the birds are now all working, either inside their tunnels or clinging to the face of the cliff. All at once, either at or about the same instant of time, they all fly off, darting away, and disseminate themselves in the sky, not one being left either in or about the pit. In a few minutes they return, but, as is the case with the small birds at the stacks, not in nearly so instantaneous or simultaneous a manner; and this may be repeated for a greater or lesser number of times. All the remarks that I have made in regard to this phenomenon in the case of other birds apply equally here, perhaps, indeed, to a greater extent; for, as remarked, at the moment of each sudden exodus a certain number—sometimes about half—of these sand-martins will be more or less hidden within the holes they are excavating, yet out they all dart with the rest. Such sudden flights and disappearances for a few minutes, after which all come back, strike me as being extremely curious.