Cormorants, as they sit on the nest, have a curious habit of twitching or quivering the muscles of the throat, so that the feathers dance about in a very noticeable manner, especially if that rare phenomenon, a glint of sunshine, should happen to fall upon them. Whilst doing so they usually sit quite still, sometimes with the bill closed, but more frequently, perhaps, with the mandibles separated by a finger's breadth or so. I have watched this curious kind of St Vitus's dance going on for a quarter of an hour or more, and it seems as though it might continue indefinitely for any length of time. All at once it will cease for a while, and then as suddenly break out again. It is not only the old birds that twitch the throat in this manner. The chicks do so too in just as marked a degree, and on account of the skin of their necks being naked it is, perhaps, more noticeable in their case than with the parent birds. I have observed exactly the same thing, though it was not quite so conspicuous, in the nightjar, so that I cannot help asking myself the question whether it stands in any kind of connection with the habit of bringing up food for the young from the crop or stomach—the regurgitatory process. I will not be sure, but I think that the same curious tremulo of the throatal feathers may be observed in pigeons as they sit on the nest. It is that portion of the throat which lies just below the bird's gape (I am here speaking of the shag), including both the feathered and the naked skin between the cleft of the lower mandible, and extending to the sides of the neck, which is principally twitched or quivered.
The above, perhaps, is a trivial observation, but no one can watch these birds very closely without being struck by the habit.
Young shags are, at first, naked and black—also blind, as I was able to detect through the glasses. Afterwards the body becomes covered with a dusky grey down, and then every day they struggle more and more into the likeness of their parents. They soon begin to imitate the grown-up postures, and it is a pretty thing to see mother and young one sitting together with both their heads held stately upright, or the little woolly chick standing up in the nest and hanging out its thin little featherless wings, just as mother is doing, or just as it has seen her do. At other times they lie sprawling together either flat or on their sides. They are good-tempered and playful, seize playfully hold of each other's bills, and will often bite and play with the feathers of their parent's tail. In fact, they are a good deal like puppies, and the heart goes out both to them and to their loving, careful, assiduous mother and father. As pretty domestic scenes are enacted daily and hourly on this stern old rock, within the very heave and dash of the waves, as ever in Arcadia, or in any neat little elegant bower where the goddess of such things presides—or does not. The sullen sea itself might smile to watch its pretty children thus at play, and to me it seemed that it did.
Guarding the nest and affairs of honour.—When both birds are at home, the one that stands on the rock, by or near the nest, is ready to guard it from all intrusion. Should another bird fly on to the rock and alight, in his opinion, too near it, he immediately advances towards him, shaking his wings, and uttering a low, grunting note which is full of intention. Finding itself in a false position, the intruding bird flies off; but it sometimes happens that when two nests are not far apart, the sentinels belonging to each are in too close a proximity, and begin to cast jealous glances upon one another. In such a case, neither bird can retreat without some loss of dignity, and, as a result, there is a fight. I have witnessed a drama of this nature. As in the case of the herring-gulls, the two locked their beaks together, and the one which seemed to be the stronger endeavoured with all his might to pull the other towards him, which the weaker bird, on his part, resisted as desperately, using his wings both as opposing props, and also to push back with. This lasted for some while, but the pulling bird was unable to drag the other up the steeply-sloping rock, and finally lost his hold. Instead of trying to regain it, he turned and shuffled excitedly to the nest, and when he reached it the bird sitting there stretched out her neck towards him, and opened and shut her beak several times in quick succession. It was as if he had said to her, "I hope you observed my prowess. Was it well done?" and she had replied, "I should think I did observe it. It was indeed well done." On the worsted bird's ascending the rock to get to his nest, the victorious one ran, or rather waddled, at him, putting him to a short flight up to it. But, though defeated, this bird was cordially received by his own partner, who threw up her head and opened her bill at him in the same way, as though sympathising, and saying, "Don't mind him; he's rude." In such affairs, either bird is safe as soon as he gets within close distance of his own nest, for it would be against all precedent, and something monstrous, that he should be followed beyond a certain charmed line drawn around it.
Nothing is more interesting than to look down from the summit of some precipice on to a ledge at no great distance below, which is quite crowded with guillemots. Roughly speaking, the birds form two long rows, but these rows are very irregular in depth and formation, and swell here and there into little knots and clusters, besides often merging into or becoming mixed with each other, so that the idea of symmetry conveyed is of a very modified kind, and may be sometimes broken down altogether. In the first row, a certain number of the birds sit close against and directly fronting the wall of the precipice, into the angle of which with the ledge they often squeeze themselves. Several will be closely pressed together so that the head of one is often resting against the neck or shoulder of another, which other will also be making a pillow of a third, and so on. Others stand here and there behind the seated ones, each being, as a rule, close to his or her partner. There is another irregular row about the centre of the ledge, and equally here it is to be remarked that the sitting birds have their beaks pointed towards the cliff, whilst the standing ones are turned indifferently. There are generally several birds on the edge of the parapet, and at intervals one will come pressing to it through the crowd in order to fly down to the sea, whilst from time to time, also, others fly up and alight upon it, often with sand-eels in their beaks. On a ledge of, perhaps, some dozen or so paces in length, there may be from sixty to eighty guillemots, and as often as they are counted the number will be found to be approximately the same.
Most of the sitting birds are either incubating or have young ones under them, which, as long as they are little, they seem to treat very much as though they were eggs. Others, however, when they stand up are seen to have nothing underneath them, for as with other sea-birds, so far as I have been able to observe, there seems to be a great disparity in the time at which different individuals begin to lay. In the case of the puffin, for instance, some birds may be seen collecting grass and taking it to their burrows, whilst others are bringing in a regular supply of fish to their young. Much affection is shown between the paired birds. One that is sitting either on her egg or young one—for no difference in the attitude can be discovered—will often be very much cosseted by the partner who stands close behind or beside her. With the tip of his long, pointed beak he, as it were, nibbles the feathers (or perhaps, rather, scratches and tickles the skin between them) of her head, neck, and throat, whilst she, with her eyes half closed, and an expression as of submitting to an enjoyment—a "Well, I suppose I must" look—bends her head backwards, or screws it round sideways towards him, occasionally nibbling with her bill, also, amidst the feathers of his throat, or the thick white plumage of his breast. Presently, she stands up, revealing the small, hairy-looking chick, whose head has from time to time been visible, just peeping out from under its mother's wing. Upon this the other bird bends its head down and cossets in the same way—but very gently, and with the extreme tip of the bill—the little tender young one. The mother does so too, and then both birds, standing together side by side over the chick, pay it divided attentions, seeming as though they could not make enough either of their child or each other. It is a pretty picture, and here is another one. "A bird—we will think her the female, as she performs the most mother-like part—has just flown in with a fish—a sand-eel—in her bill. She makes her way with it to the partner, who rises and shifts the chick that he has been brooding over from himself to her. This is done quite invisibly, as far as the chick is concerned, but you can see that it is being done.
"The bird with the fish, to whom the chick has been shifted, now takes it in hand. Stooping forward her body, and drooping down her wings, so as to make a kind of little tent or awning of them, she sinks her bill with the fish in it towards the rock, then raises it again, and does this several times before either letting the fish drop or placing it in the chick's bill—for which it is I cannot quite see. It is only now that the chick becomes visible, its back turned to the bird standing over it, and its bill and throat moving as though swallowing something down. Then the bird that has fed it shifts it again to the other, who receives it with equal care, and bending down over it, appears—for it is now again invisible—to help or assist it in some way. It would be no wonder if the chick had wanted assistance, for the fish was a very big one for so small a thing, and it would seem as if he swallowed it bodily. After this the chick is again treated as an egg by the bird that has before had charge of him—that is to say, he is sat upon, apparently, just as though he were to be incubated—or suppressed, like the guinea-pigs in 'Alice in Wonderland.'"
On account of the closeness with which the chick is guarded by the parent birds, and the way in which they both stand over it, it is difficult to make out exactly how it is fed; but I think the fish is either dropped at once on the rock or dangled a little, for it to seize hold of. It is in the bringing up and looking after of the chick that one begins to see the meaning of the sitting guillemots being always turned towards the cliff, for from the moment that the egg is hatched, one or other of the parent birds interposes between the chick and the edge of the parapet. Of course I cannot say that the rule is universal, but I never saw a guillemot incubating with its face turned towards the sea, nor did I ever see a chick on the seaward side of the parent bird who was with it. It seems probable that the relative positions of the sitting bird and the egg would be continued from use after the latter had become the young one; and if we suppose that in a certain number of cases where these positions were reversed the chick perished from running suddenly out from under the parent and falling over the edge of the rock, we can understand natural selection having gradually eliminated the source of this danger. But natural selection may have acted in another direction, which would have been still more conducive to the safety of the chick. I observed that the latter—even when, as I judged by its tininess, it had only been quite recently hatched—was as alert and as well able to move about as a young chicken or partridge; but whilst possessing all the power, it appeared to have little will to do so. Its lethargy—as shown by the way in which, even when a good deal older, it would sit for hours without moving from under the mother—struck me as excessive; and it would certainly seem that on a bare narrow ledge, to fall from which would be certain death, chicks of a lethargic disposition would have an advantage over others who were fonder of running about. If we suppose that a certain number of chicks perished even amongst those whose parents always stood between them and the sheer edge, we can understand both the one and the other step towards security having been brought about, either successively or side by side with each other.
From the foregoing it would appear that the young guillemot is fed with fish which are brought straight from the sea in the parent's bill, and not—as in the case of the gulls—disgorged for them after having been first swallowed. It is, however, a curious fact that the fish when thus brought in is, sometimes at any rate, headless. The reason of this I do not know, but with the aid of the glasses I have made quite certain of it, and each time it appeared as though the head had been cleanly cut off. Moreover, on alighting on the ledge the bird always has the fish (a sand-eel, whenever I saw it) held lengthways in the beak, with the tail drooping out to one side of it, and the head part more or less within the throat—a position which seems to suggest that it may have been swallowed or partially swallowed—whereas puffins and razorbills carry the fish they catch crosswise, with head and tail depending on either side.
I have also once or twice thought that I saw a bird which just before had had no fish in its bill, all at once carrying one. But I may well have been mistaken; and it does not seem at all likely that the birds should usually carry their fish, and thus, as will appear shortly, subject themselves to persecution, if they could disgorge it without inconvenience. With regard to the occasional absence of the head, perhaps this is sometimes cut off in catching the fish, or before it is swallowed, which may also have been the case with the herrings brought by the great skuas to their young. However, I can but give the facts, as far as I was able to observe them.