The birds of Jamaica

by Philip Henry Gosse

The first specimen that fell under my observation was shot in October. On several evenings in succession a large bird had been observed sitting on a particular post near Bluefields Tavern, where it remained undisturbed by passers looking at it, though it was not half a stone’s cast from the road-side. At length Sam shot at it, and blew out many feathers, but it flew slowly off to the woods; uttering, the instant after it was shot, a low croaking. The next evening he watched again, and about sunset the bird returned to the same post, when he secured it. It is interesting to observe the similarity in habit to the Flycatchers in selecting a prominent station, and returning again and again to it, even after such annoyance. It was one out of many posts of a rail-fence, yet the bird uniformly chose the same. Another was given me a few weeks afterwards, which had been struck down with a stone, as it was sitting on a tree in the yard around a negro’s house. It had been in the habit of stationing itself there every evening, and its cries, which were described to me as resembling the mewing of a cat in pain, were so plaintive, that they seem to have acted on the good woman’s superstition, who begged her husband to kill it. I incline to think, however, that the voice here mentioned was not that of the Potoo, but of an Eared Owl which may have been near it, but in the darkness unobserved. This specimen lived a day or two in the house, after it was knocked down, and when it died it was brought to me. I found its stomach, a muscular gizzard, distended with large beetles, (Megasoma titanus,) disjointed. That of the former contained two specimens of a black Phanæus.

Another, a male, shot in the day time, in February, had the stomach hard stuffed with fragments of insects, which, on being dispersed in water, I found to consist wholly of beetles, among which limbs of lamellicorns were conspicuous, probably Phanæus. In this case the stomach was more membranous; the œsophagus very wide and substantial as in the Owls, but there was no dilatation or proventriculus.

About the same time a living and uninjured specimen was given me, taken in a wooded morass. This I kept some days. It would sit anywhere that it was placed, across the finger, or across a stick; never lengthwise, though I repeatedly tried it so. Its position in sitting was quite perpendicular, (that is, from head to tail,) the plumage a little puffed out, the head drawn in, the eyes usually shut. When pushed, however, it lengthened the neck to retain its balance, and opened its eyes, which being so large, and the irides of a brilliant yellow, combined with the wide gape to give it a most singular physiognomy. Usually it seemed absolutely blind by day, for when the eyes were wide open, the approach of any object within a line of the pupil, and the moving of it to and fro, produced, in general, not the slightest effect. Once or twice, however, I observed that when the pupil was greatly dilated, as it always was when the lids were first unclosed, the sudden motion of my hand towards the eye, caused the pupil to contract with singular rapidity to less than one fourth of its former dimensions. Afterwards by candle-light, I observed the extraordinary rapidity and extent of this contractility more fully. When the candle was little more than a yard distant, the pupil was dilated to about ³⁄₄ths of an inch diameter, occupying the whole visible area of the eye, the iris being reduced to an imperceptible line; on bringing the candle close to the pupil, it contracted to a diameter of two lines, and that completely within the period required to convey the candle by the most rapid action of my hand practicable.

As night approached I expected that it would become animated; but it did not stir, nor shew any sign of vivacity, though I watched it till it was quite dark. Several times in the evening I went into the room, up to ten o’clock, but it was where I had left it. About three in the morning I had occasion to go in again with a candle; the Potoo had not altered his position, and when the day came, there he was unmoved, nor do I believe he had stirred during the whole night. Thus he remained during the next day; I put his beak into water, and let fall drops upon it, but he refused to drink: I then caught beetles (Tenebrionidæ) and cockroaches, but he took no notice of them; and though I repeatedly opened his beak and put the insects into his broad and slimy mouth, they were instantly jerked out by an impatient toss of his head. Towards this evening, however, he began to glower about, and once or twice suddenly flew out into the midst of the room, and then fluttered either to the ground, or to some resting place. Many little Tineæ were flitting around my dried bird-skins, and I conjectured that he might be capturing these, especially as when at rest his eye would now and then seem to catch sight of some object, and glance quickly along, as if following its course. The statement of Cuvier, that “the proportions of the Nyctibius completely disqualify it from rising from a level surface,” I saw disproved; for notwithstanding the shortness of the tarsi, (and it is, indeed, extreme,) my bird repeatedly alighted on, and rose from, the floor, without effort. When resting on the floor, the wings were usually spread; when perching, they about reached the tip of the tail. If I may judge of the habits of the Potoo from what little I have observed of it when at liberty, and from the manners of my captive specimen, I presume that, notwithstanding the powerful wings, it flies but little; but that sitting on some post of observation, it watches there till some crepuscular beetle wings by, on which it sallies out, and having captured it with its cavernous and viscid mouth, returns immediately to its station. Mr. Swainson appears to consider that the stiff bristles, with which many Caprimulgidæ are armed, have a manifest relation to the size and power of their prey, beetles and large moths, while these appendages are not needed in the swallows, their prey consisting of “little soft insects.” (Class. Birds.) But here is a species, whose prey is the hardest and most rigid beetles, of large size, and often set with formidable horns,—which has no true rictal bristles at all!

Finding that my Potoo would not eat, and feeling reluctant to starve it, I killed it for preparation. In depriving it of life, I first endeavoured to strangle it by pressure on the trachea, but I found that with all the strength of my fingers, I could not compress it so as to prevent the admission of air sufficient for respiration. I was obliged, therefore, to apply one or two smart blows on the head with a stick. While giving it these death-blows, much against my feelings, it uttered, on being taken up by the wings, a short, harsh croaking. With this exception, it was absolutely silent all the time I had it; never resenting any molestation, save that when irritated by the repeated presentation of any object, as the corner of a handkerchief, it would suddenly open its immense mouth, apparently for intimidation; yet it made no attempt to seize anything. The stomach, notwithstanding three or four days’ fast, was crammed with fragments of beetles, among which were the horns of a large Dynastes, that I had not met with. I may mention that the sclerotic ring of the eye consists of distinct plates (see Pen. Cyc. xvi. 225,) thirteen in number, varying in dimensions, and not perfectly regular in form.

I afterwards kept a living Potoo for ten days; but its manners were exactly the same as above, pertinaciously refusing to eat. Mr. Hill, however, had one which greedily ate large cockroaches that were thrown to it.

It is remarkable that among a people whose most striking feature is the great development of the mouth, the Potoo has become a proverb of ugliness. The “most unkindest cut of all” that a negro can inflict upon another, on the score of personal plainness, is “Ugh! you ugly, like one Potoo!”

I have seen that which serves this bird for a nest: it is simply a round, flat mat, about five inches wide, and little more than one thick, composed of the fibrous plant called Old man’s beard (Tillandsia usneoides). It was found on the ground on a spot whence the Potoo had just risen: it is in the possession of Mr. Hill, to whom I am indebted for the following interesting observations.

“White’s conjecture of the purpose to which the serrated toe of the Nightjar is applied, namely, the better holding of the prey which it takes with its foot while flying, would have been more than rendered highly probable by an inspection of the foot of the Nyctibius. The inner front toe and the back toe are spread out by the great extension of the enveloping flesh of the phalanges, to such a breadth as to give the foot the character and form of a hand; while the movement of these prehensile organs is so adjusted that the back toe and the three front toes, pressed flat against one another, can enclose anything as effectually as the palms of the hands. The [claw of the] middle toe, which is serrated in the Caprimulgus, is simply dilated in the Nyctibius, a peculiarity also of the swallows. Whatever deficiency of prehension this may give it, when compared to the power of the serrated nail of the Caprimulgus, is amply compensated for in the Nyctibius, by the palm-like character of the foot, by the extraordinary expansion of the toes, and by the quantity of membrane connecting them together. All this would be a mere waste of power if it did not perform some function like that which White assigned to the foot of the Nightjar.

“The feathers of the head, but especially those around the dilated gape, are of a peculiar structure. The covering of this part appears at first sight a mixture of hair and feathers, but upon close inspection, it is found to be composed of a loosely woven plumage, in which the shaft of each feather is prolonged into a pliant filament of great length. It is this texture which gives the character of intermingled hairs to the feathers around the mouth. This tendency in the shafts and in some of the webs also to terminate in filaments is very prevalent in the plumage of the Nyctibius, each of the feathers of the tail having this sort of termination.”