Part 70

The inside of the mouth and the gular sac flesh-coloured; the bill dusky, at the base flesh-coloured; the eyes bluish grey. The general colour of their skin is dull livid; the feet purplish-dusky, the webs yellowish-brown.

The following is a description of the smaller individual represented in the plate, and which was about two weeks old. The length is twelve inches and a half; the colour dull livid, the abdomen and breast lighter, the forehead, gular sac, and bases of the mandibles, flesh-colour tinged with yellow, as is the mouth. The head and upper part of the neck are bare, as well as the lower surface of the wings. Over the rest of the body are small down tufts rising in regular series, excepting along an impressed line extending from the anterior part of the thorax to the anus. The apertures of the ears are round, extremely small, being only half a twelfth in diameter; the eyes very small, the iris grey. The aperture of the posterior nares is linear-lanceolate, smooth on the edges, half an inch long. A probe introduced into it passes readily out by the nostril, which is basal, linear, small, two-twelfths long, placed at the commencement of the long groove which separates the sides from the ridge of the mandible, and covered above by the skin, so as to be not readily observed, although it is easily dilatable. Each internal nostril is oblique, much wider below, and has on its inner side a transverse soft ridge, which divides it into two cavities, the posterior deep and funnel-shaped, passing backwards and upwards, the anterior becoming narrower towards the external aperture. The tongue is extremely small, four-twelfths long, elliptical, with a central ridge. The œsophagus is extremely dilatable, and as far as the middle of the neck is of larger diameter than below, but it again dilates as it enters the stomach. Its length is five inches and a half. The inner coat is smooth in its dilated part, but in the rest is raised into numerous longitudinal ridges or folds, which at the lower part are undulated. The stomach is oblong, four and a half inches long, quite membranous, and without apparent central tendons. The gastric glands are disposed so as to occupy two spaces, the one three and a half inches by two, the other a little smaller. The inner coat is soft and without wrinkles. The intestine is five feet two inches long, at its upper part three-twelfths in diameter, gradually diminishing to one-twelfth. At the distance of two inches from the anus are two cœca, three-twelfths long, one-twelfth in diameter, and rounded. The contents of the stomach were fragments of fish, with numerous bones, and a pebble about half an inch in diameter. The heart triangular, much flattened. The liver of two very unequal lobes, the right one two inches and a half long, the other one and a half. The specimen, which I had preserved in spirits, was examined in my presence by my friend Mr MACGILLIVRAY. Whether the fact of the anterior aperture of the organ of smell being open in the young Cormorant has been observed by any other person than myself, I know not; but it would seem that the general opinion is, that Cormorants have no external nares in any stage, and although some state that in the adult they exist, and are extremely small, others allege that there are none at all.

A young female, shot in the end of October, on being carefully examined, was found to present the following characters.

The length to the end of the tail was 36 inches, to the end of the wings 29-3/4, to the end of the outer toe 34-1/2; the extent of the wings 55; the weight 5 lb. 10-1/2 oz.

Bill along the ridge and unguis black, the sides brownish-grey; the lower mandible brownish-grey, dusky on the sides at the middle, the bare skin at the base yellow, as is the gular sac. Upper part of the head and hind neck brownish-black; the back greenish-black, its fore part, the scapulars and the wing-coverts brownish-grey, the feathers edged with greenish-black, and an outer margin of brownish-white, most conspicuous on the secondary coverts; the quills brownish-black, the secondaries tinged with grey on the outer edge; the tail greyish-black, the shafts greyish-blue. Upper part of the throat brownish-white; the rest of the neck greyish-white, mixed with brown; the breast and abdomen white, the sides greenish-black; the lower surface of the wings dusky; the lower tail-coverts greyish-brown, the feathers before them brownish-black. The feet greyish-black; the inner edge of the middle claws very slightly pectinated. The foot, when stretched to its full extent, measures, from the tip of the first to that of the fourth claw, 5-10/12 inches.

The tongue is oblong, carinate above, 7/12 long, 3/12 broad. The palatal slit or aperture of the posterior nares is linear, 1-2/12 long, with a soft flap on each side. The mouth is 1-5/12 wide; the bill 3-1/4 along the back, 4 along the edge of lower mandible. The aperture of the ear is circular, only half a line in diameter.

On blowing into the posterior nares no air passes. The internal cavities are separated by a longitudinal membranous dissepiment; each cavity is transversely divided by a membranous partition, but neither of the chambers thus formed has any external communication by the mandible. The lachrymal duct, which is wide, passes obliquely forward and downward into the anterior cavity. On gradually slicing the horny covering of the mandible over the place where the nostril ought to be, its position is found clearly defined, there being a slight discontinuity of the bone at that part; but on cutting farther all traces disappear, the original aperture being closed by ossification.

The aperture of the glottis has thick prominent rounded edges, which unite behind and terminate in three knobs, and there is a small transverse flap on each side behind.

The heart is triangular, depressed, obtuse, 2-1/2 inches long, its greatest breadth 1-7/12. The liver has two very unequal lobes, the right 5 inches, the left 3 inches long; the former 2-1/2 broad, the latter 1-3/4. The gall-bladder is 2-1/4 long, (3-1/2)/12 in diameter, rounded, but not much enlarged at the extremity.

The œsophagus is 22-1/2 inches long; at its upper part when dilated upwards of two inches wide, extremely thin, its circular fibres distinct. It is contracted in the whole length of the thorax, where its smallest diameter is 8/12, the largest 10/12; but this part, which in the ordinary state has its inner coat folded into numerous longitudinal wrinkles, is capable of being dilated so as to present a diameter of more than 3 inches, when the internal rugæ disappears. The proventriculus seems at first to form part of the stomach; its walls are extremely thick and studded with glandules, disposed in two circular patches, which are separated by a space of about 3/12 of an inch. The stomach properly so called is very small; its muscular coat thin, but with two distinct tendons. It is of an oblong form, compressed, and at its upper parts has a rounded lobe, from which the intestine comes off. The inner coat is thick, soft, and rugous. The pylorus has a circular marginal rim. The intestine, which is 8 feet long, is at its upper part (3-1/2)/12 in diameter, towards the cœca (2-3/4)/12. The rectum is 7 inches long, its diameter for 4-1/2 inches is 7/12; the cloaca globular, 2-2/12 in diameter; the cœca 3/12 long. The cystic duct enters one inch below the hepatic; between them enters one of the pancreatic ducts, the other 2 inches farther up. The distance from the pylorus to the hepatic duct is 16-1/2 inches.

The lungs extend to the kidneys. The ovules exceedingly small and numerous. In the proventriculus and lower part of the œsophagus were many small ascarides. The contents of the stomach were a few bones of fishes.

Although I have not actually observed that Cormorants have the power of disgorging such substances as they are unable to digest, I should not be surprised to find this to be the case, when their habits are investigated in a state of domestication.

THE ARCTIC JAGER.

LESTRIS PARASITICUS, BOIE.

PLATE CCLXVII. MALE AND FEMALE.

During winter this indefatigable teaser of the smaller Gulls often ranges along our southern coasts as far as the Mexican Gulf, where I have seen it, as well as opposite the shores of the Floridas; but I never met with a single individual in summer, even in the most northern parts, although I had expected to find it breeding on the coasts of Labrador and Newfoundland. Few birds surpass it in power or length of flight. It generally passes through the air at a height of fifty or sixty yards, flying in an easy manner, ranging over the broad bays, on which Gulls of various kinds are engaged in procuring their food. No sooner has it observed that one of them has secured a fish, than it immediately flies toward it and gives chase. It is almost impossible for the Gull to escape, for the warrior with repeated jerkings of his firm pinions sweeps towards it, with the rapidity of a Peregrine Falcon pouncing on a Duck. Each cut and turn of the Gull only irritates him the more and whets his keen appetite, until by two or three sudden dashes, he forces it to disgorge the food it had so lately swallowed. This done, the poor Gull may go in search of more; the Lestris is now for a while contented, and alights on the water to feed at leisure. But soon, perceiving a distant flock of Gulls, he rises on wing and speeds towards them. Renewing his attacks, he now obtains an abundant supply, and at length, when quite gorged, searches for a place on which to alight, unseen by any other of his tribe more powerful than himself. When on wing, its beautiful long tail-feathers seem at times to afford this bird great assistance in executing short sudden turns, which have often brought to my mind the motions of a greyhound while pursuing a hare. By sudden lashings of its tail, it can instantly turn, or arrest its flight. When it is on the water, it keeps that part upright, but when on a rock or a floating piece of timber, it allows it to fall in a graceful manner.

Although usually seen single, or at most in pairs, during the winter, I observed this species in April, on my voyage to the Florida Keys, in flocks of from ten to fifteen, congregated as if for the purpose of returning to the northern regions, where it is said to breed in groups. Mr SELBY, in treating of this bird, says “It breeds upon several of the Orkney and Shetland Isles, and is gregarious during that period; and the situations selected for nidification are the unfrequented heaths at some distance from the shores. The nest is composed of dry grass and mosses, and its two eggs are of a dark oil-green, with irregular blotches of liver-brown. At this season the bird is very courageous, and, like the Common Skua, attacks every intruder upon the limits of its territory, by pouncing and striking at the head with its bill and wings. It also occasionally endeavours to divert attention by feigning accidental lameness.” Having received eggs of this bird from individuals who had collected them, I may add that they are broadly rounded at the larger end, rather pointed at the smaller, have a smooth shell, and average two inches four-twelfths in length, by one inch and four and a half eighths in breadth.

M. TEMMINCK, in his Manuel d’Ornithologie, describes the young when about to leave the nest as follows: “Top of the head of a deep grey; sides and upper part of the neck of a light grey, sprinkled with longitudinal brown spots; a black spot before the eyes; lower part of the neck, back, scapulars, small and large wing-coverts, umber-brown, each feather bordered with yellowish-brown, and often with reddish; lower parts irregularly variegated with deep brown and yellowish-brown on a whitish ground; tail-coverts and abdomen transversely barred; quills of the wings and tail blackish, white at their base and on the inner barbs, all terminated with white; the two outer shafts white; tail only rounded; base of the bill yellowish-green, black towards the point; tarsi bluish-grey; base of the toes and membranes white, the rest black, hind claw often white.”

In middle age, he says, “all the upper parts are greyish-brown without spots; lower parts of a somewhat lighter tint, and also unspotted; inner base of the quills and only the upper parts of the tail-feathers pure white, the rest blackish-brown; the two elongated tail-feathers gradually diminish in breadth towards the extremity, which ends in a very attenuated point; bill and feet as in the old individuals.”

Captain JAMES CLARK ROSS has informed me by letter, that this species was seen in great numbers during his late voyage towards the Arctic circle; that the Pomarine Lestris was less abundant, and RICHARDSON’s very rare.

LESTRIS BUFFONII, Ch. Bonaparte, Synopsis of Birds of the United States, p. 364.

LESTRIS, ARCTIC JAGER, Swains. and Richards. Fauna Bor. Amer. part ii. p. 430.

ARCTIC JAGER, Nuttall, Manual, vol. ii. p. 317.

Adult Male. Plate CCLXVII. Fig. 1.

Bill about the length of the head, rather slender, straight, the tip curved. Upper mandible with the dorsal line straight, toward the end curved, the ridge broad and convex, the sides separated from the ridge by a narrow groove, extremely narrow and convex, the edges sharp and inflected, the tip compressed, rather obtuse. Nostrils in the fore part of the nasal groove, nearer the tip than the base, submarginal, pervious, linear, oblong, wider anteriorly. Lower mandible with the angle long and narrow, a slight prominence at its extremity, beyond which the dorsal line is straight and ascending, the sides sloping outwards and convex, the edges sharp and inflected, the tip obliquely truncate and rather obtuse.

Head rather small, oblong, much narrowed before. Neck of moderate length. Body rather slender. Feet rather short and of moderate strength; tibia bare at its lower part; tarsus anteriorly covered with broad decurved scutella, on the sides with oblong scales, behind with smaller oblong prominent scales; hind toe extremely small and elevated, the fore toes of moderate size, connected by reticulated webs, which have their margins convex; the third toe longest, the fourth not much shorter, all covered above with numerous scutella, the lateral ones margined externally with small prominent scales directed forwards. Claws of moderate size, curved, acute, compressed, that of third toe with a sharp inner edge.

The plumage in general is close, elastic, soft, and blended; the feathers on the back and wings rather compact and distinct. Wings very long, rather broad, pointed; primary quills tapering and rounded, the first longest, the rest rapidly graduated; secondary rather short, rounded. Tail feathers of moderate length excepting the two middle, which are extremely elongated and gradually attenuated, the rest broad and rounded, there being twelve in all.

Bill greyish-black, the upper part bluish. Iris brown. Feet black, but with the greater part of the tarsus yellow. The neck and lower parts are white, the former tinged with yellow; upper and fore part of head with the space before the cheeks blackish-brown; the lower part of the hind neck and all the upper parts blackish-grey, the primary quills and tail-feathers brownish-black, the shafts of the former white.