_Nyctibius Jamaicensis._
_Caprimulgus Jamaicensis_, +Gmel.+
_Nyctibius Jamaicensis_, +Vieill.+
_Nyctibius pectoralis_, +Gould+, Ic. Av.
[10] Length 16 inches, expanse 33¹⁄₂, tail 7³⁄₄, flexure 11¹⁄₄,
rictus 2¹⁄₂, breadth of beak at base measured within 2²⁄₁₀, tarsus
³⁄₁₀, middle toe 1³⁄₁₀.
Irides hazel, orange-coloured, or brilliant straw-yellow; feet
whitish, scurfy; beak black. Interior of mouth violet, passing
into flesh-colour. Plumage mottled with black, brown, grey, and
white; the white prevailing on the tertiaries, tertiary-coverts,
and scapulars, the black upon the primaries and their coverts; the
tail-feathers barred transversely with black on a grey ground,
which is so mottled as to bear a striking resemblance to the soft
pencilling of many Sphingidæ; tail broad, very slightly rounded.
The feathers of the head lax, and fur-like. Inner surface of the
wings black, spotted with white. A streak of black runs on each
side the throat, nearly parallel with and close to the gape; a
bay tint prevails on the breast; and some of the feathers there
have broad terminal spots of black, which are arranged in somewhat
of a crescent-form, having irregular spots above it. Under parts
pale grey unmottled. Every feather of the whole plumage is marked
with a black stripe down the centre. Tongue sagittiform, wide at
the horns, slender towards the tip, fleshy; reverted barbs along
the edges. The volume of brain excessively small. Intestine 10¹⁄₂
inches; two cæca 1¹⁄₂ in. long, dilated at the ends.
Both the Whip-poor-will and the Chuck-will’s-widow have been assigned
to Jamaica; neither of these vociferous and unmistakable birds,
however, have fallen under my observation there. It is not improbable
that the present bird has been mistaken by careless observers for the
Chuck-will’s-widow, though comparatively a silent species.
The Potoo is not unfrequently seen in the evening, taking its station
soon after sunset on some dead tree or fence-post, or floating by on
noiseless wing, like an owl, which the common people suppose it to
be. Its plumage has the soft puffy, unwebbed character which marks
that of the owls, and which prevents the impact of its wings upon the
air from being audible, notwithstanding the power and length of those
organs. Now and then it is seen by day; but it is half concealed in
the bushy foliage of some thick tree, which it can with difficulty be
induced to quit, distrustful of its powers by day. As it sits in the
fading twilight it ever and anon utters a loud and hoarse _ho-hoo_, and
sometimes the same syllables are heard, in a much lower tone, as if
proceeding from the depth of the throat.
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.”
The Potoo is a permanent inhabitant of Jamaica; it is common in the
lowlands of the south side, and probably is generally distributed in
the island: it is found also in Brazil, for I am quite satisfied that
Mr. Gould’s _N. Pectoralis_ is not specifically distinct from ours.