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The Common Cormorant


The Common Cormorant


The definitive website on wildbirds & nature



Birds of America

By John James Audubon, F. R. SS. L. & E.

VOLUME VI.

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Family
Genus

THE COMMON CORMORANT.
[Great Cormorant.]

PHALACROCORAX CARBO, Linn.
[Phalacrocorax carbo.]

PLATE CCCCXV.--MALE, FEMALE, AND YOUNG.

Look at the birds before you, and mark the affectionate glance of the mother, as she stands beside her beloved younglings! I wish you could have witnessed the actions of such groups as I did while in Labrador. Methinks I still see the high rolling billows of the St. Lawrence breaking in foaming masses against the huge cliffs, on the shelves of which the Cormorant places its nest. I lie flat on the edge of the precipice some hundred feet above the turbulent waters, and now crawling along with all care, I find myself only a few yards above the spot on which the parent bird and her young are fondling each other, quite unconscious of my being near. How delighted I am to witness their affectionate gratulations, hear their lisping notes, mark the tremulous motions of their expanded throats, and the curious vacillations of their heads and necks! The kind mother gently caresses each alternately with her bill; the little ones draw nearer to her, and, as if anxious to evince their gratitude, rub their heads against hers. How pleasing all this is to me! But at this moment the mother accidentally looks upward, her keen eye has met mine, she utters a croak, spreads her sable wings, and in terror launches into the air leaving her brood at my mercy. Far and near, above and beneath me, the anxious parent passes and repasses; her flight is now unnatural, and she seems crippled, for she would fain perform those actions in the air, which other birds perform on the ground or on the water, in such distressing moments of anxiety for the fate of their beloved young. Her many neighbours, all as suspicious as herself, well understand the meaning of her mode of flight, and one after another take to wing, so that the air is in a manner blackened with them. Some fly far over the waters, others glide along the face of the bold rock, but none that have observed me realight, and how many of those there are I am pretty certain, as the greater number follow in the track of the one most concerned. Meanwhile the little ones, in their great alarm, have crawled into a recess, and there they are huddled together. I have witnessed their pleasures and their terrors, and now, crawling backwards I leave them to resume their ordinary state of peaceful security.

It was on the 3d of July, 1833, about three in the morning, that I had the pleasure of witnessing the scene described above. I was aware before that a colony of Cormorants had nestled on the ledges of the great rocky wall that separated our harbour of Whapatiguan from the waters of the Gulf of St. Lawrence. A strong gale had ruffled the sea, and the waves dashed with extreme violence against the rocks, to which circumstance, I believe, was owing my having remained awhile unseen and unheard so near the birds, which were not more than four or five yards below me. The mother fondled and nursed her YOUNG with all possible tenderness, disgorged some food into the mouth of each, and coaxed their with her bill and wings. The little ones seemed very happy, billed with their mother, and caressed her about the breast. When the parent bird flew off on observing me, the young seemed quite frightened, squatted at once on their broad nest, and then crawled with the aid of their bills until they reached a recess, where they remained concealed.

On another occasion, my young friends LINCOLN and COOLEDGE, along with my son, went to the same rocks, for the purpose of bringing me a nest and some of the young Cormorants. They reported that, in one instance, they surprised the parent birds close beneath them, apparently asleep, resting on their rumps in an upright position, with the head thrust under the wing, and that, had they had a noose attached to their poles, they might have secured at least one of them, but that after a few minutes one drew out her head, stretched her neck, and after looking around flew off croaking, so as to alarm all her neighbours.

We saw no nests of this species placed in any other situations than the highest shelves of the precipitous rocks fronting the water and having a southern exposure. No other Cormorants bred on the spots of which this kind had taken possession; but Ravens and Peregrine Falcons were observed to have nests on the same rocks, and in some instances close to them. The nests were formed of a quantity of small dry sticks, matted in a rude manner with a large quantity of weeds and moss, to a thickness of four or five inches in new nests, and in others to that of a foot or more; for we observed that this species, as well as the Double-crested and the Florida Cormorants, repair and enlarge their tenements each season, and return to the same rocks many years in succession, as was shewn by their places of resort remaining white-washed with excrements through the winter, in which condition we saw them previous to the arrival of the birds that season. The nests varied in breadth according to the space on which they were placed; where there was ample room, they measured at the base from thirty to thirty-six inches in diameter; others were scarcely large enough to hold the young, which nevertheless seemed as contented as their neighbours. On some shelves, eight or ten yards in extent, the nests were crowded together; but more usually they were placed apart on every secure place without any order; none, however, were below a certain height on the rocks, nor were there any on the summit. The nests being covered with filth, were offensive to the eye, and still more so to the nose. The eggs, three or four in number, more frequently the former, average two inches and five-eighths in length, by one inch and three-quarters in breadth, the shell of a uniform pale bluish-green colour, mostly coated over with calcareous matter.

The young are at first of a dark purplish livid colour, and have a very uncouth appearance, their legs and feet seeming enormous. In less than a fortnight they become covered on all the upper parts with brownish-black down, but the abdomen remains bare much longer than the rest. They increase rapidly in size, and are fledged in six or seven weeks. Some that were weighed when about a month old, averaged three pounds, and others almost able to fly six pounds, the young of this species, as of most water birds, being much heavier than the parent at the time of leaving the nest. We procured several of different sizes, which we kept on the deck. Whenever a person approached them, they raised their heads, stretched their necks, and opened their bills, so as to expand the skin of the throat, which they made to vibrate, while they uttered a sort of hissing mutter of a very strange character, but resembling that of the young of the Brown Pelican. They crawled sluggishly about, aiding themselves in their progress with their bills, and at all times looked extremely clumsy. They took food very readily, ate a prodigious quantity, certainly more than their own weight each day, and appeared always ready to receive more. When thrown overboard, they swam off under water, like the old birds, with considerable speed, moving their unfledged wings all the while. Some would not rise for twenty or thirty yards, but few went farther under water than that distance, and they were soon fatigued. On one occasion, some half-grown young birds threw themselves from their nest, or were pushed off by their parents while in the agonies of death, they having been shot at. As they passed quickly downwards through the air, they moved their wings with great rapidity, and the instant they reached the water they disappeared beneath the surface.

This Cormorant swims at times with astonishing speed, keeping itself deeply immersed. Now and then, should it apprehend danger, it sinks so far as to shew only the head and neck, in the manner of the Anhinga. When searching for food in clear shallow water, they frequently swim with the rump rather elevated, and the head under, in the manner of the Shoveller Duck on such occasions, as if they were looking for prey on the bottom; but I never observed them act thus when the depth of water exceeded a few yards. They secure their prey by diving and pursuing it under water, with the wings partially extended and employed as paddles, while the tail directs their course, and cheeks or accelerates their speed. I have observed this in the Florida Cormorant, as well as in the present species. I never saw one while flying plunge after its prey; but I have repeatedly seen them drop from a rock headlong into the sea when shot at for the purpose of observing their actions.

Cormorants, Pelicans, Ducks, and other water birds of various kinds, are, like land birds, at times infested with insects which lodge near the roots of their feathers; and to clear themselves of this vermin, they beat up the water about them by flapping their wings, their feathers being all the while ruffled up, and rub or scratch themselves with their feet and claws, much in the same manner as Turkeys and most land birds act, when scattering up the dry warm earth or sand over them. The water birds after thus cleansing themselves remove, if perchers, and able to fly, to the branches of trees, spread out their wings and tail in the sun, and after awhile dress their plumage. Those which are not perchers, or whose wings are too wet, swim to the shores, or to such banks or rocks as are above water, and there perform the same process. The Florida Cormorant is especially addicted to this practice, and dives and plumes itself several times in the day. The Double-crested and the present species, which inhabit colder regions, seem to be satisfied with less frequent trimming, and go through the operation only once a-day, at the warmest period. I never observed any of these birds in their natural free state perform these actions in rainy or even cloudy weather, but have frequently seen Cormorants in a state of captivity do so on small artificial ponds, such as those of the London Zoological Gardens.

When they have landed after cleansing themselves by washing, they usually extend their wings, and flap them for awhile, in the manner of young birds of any kind when trying the strength of their wings before leaving the nest. They are extremely regular in returning to the same places to roost, at the approach of night, when hundreds appear to congregate on their way there, as they pass over the different fishing grounds. Those that have no broods, spend the night apart from the rest, standing nearly erect in files on the most elevated shelves, to which they ascend in the manner of some Hawks, when about to perch on any elevated spot. In winter, however, I observed some near Boston roosting singly, and immediately over their fishing places, which are usually the eddies under the projecting points of rocky islands. They are shy and wary at all periods; but when congregated in the day, it is almost impossible to approach them while fishing, for they dive and return to the surface one after another, so that one or more are constantly on the watch, and act as sentinels. It is in general quite useless to pursue one that has been wounded.

The flight of this species is strong, swift, and remarkably sustained. They usually fly in long strings, now and then forming angles, at a moderate elevation in the air. When on the rocks, they stand erect on their rump, with the neck gracefully curved, and resting between the shoulders. You may see them in hundreds, when they look like a crowd of black dominoes. If alarmed, they extend their neck to its full length, and move their head sideways to observe your motions; and if you approach them, they gradually raise and extend their wings, elevate the tail, incline the body forwards, and fly off in silence.

All our Cormorants feed principally on fish of various kinds. When they have seized one that is too large to be swallowed entire, they carry it to the shore, or to the branch of a tree, and there thrash and tear it to pieces. Some fishes which they have swallowed evidently incommode them, and on such occasions I have sometimes seen them shake their heads with great violence, and disgorge the fish, or pass it downwards into the stomach. The young ones which we kept several weeks at Labrador, performed both actions, but generally the first. All the species are expert at tossing up a fish inconveniently caught, a foot or so above their head, and receiving it in their extended gullet, in the same manner as the Frigate Pelican. Some which I have observed in a domesticated state, were so expert at receiving a fish thrown to them from the distance of several yards, by a sudden and precise movement of the neck and head, as seldom to miss one in a dozen.

The courtship of this species is so similar to that of the Florida Cormorant, that I consider it unnecessary to describe it, as I should merely repeat what is said with respect to that species. I have seen them act in the same manner, both on the shelves on which the nests were placed, and on the water. They begin to lay about the first of June, on the islands near the Bay of Fundy, about a fortnight later in Labrador; and it is my opinion that the younger birds spend their breeding season in the former places.

The Common Cormorant walks in a waddling and awkward manner, but at a good pace, and leaps from one stone to another, assisting itself with its wings, and occasionally with the tail, which acts as a kind of spring. I am unable to say at what age this species attains the full dress of the love season, but it cannot be in less than three years, as some which I have known to have been kept in a state of constant captivity, did not shew the white patch on the thigh, nor the slender white feathers around the head and part of the neck, until the middle of May, in the fifth year. That the younger birds of this and other Cormorants, breed before they have acquired the full beauty of their plumage, is a fact which I have had many opportunities of ascertaining. The Common Cormorant is found breeding, both near the entrance of the Bay of Fundy, and along the coast of Labrador, in flocks of fifty or more pairs, of which not an individual shews any white unless on the sides of the head, and along the throat, but much duller on these parts than even in the female represented in the plate, which was yet what may be termed an immature bird. No differences appear in the garb of the sexes, in their different states of plumage, and perfect specimens of both are equally beautiful in the breeding season, being then similar to the male of which I have endeavoured to present a good portrait. I have observed a greater difference in size between individuals of this species, than those of any other.

The white markings observed on the old birds of this species, during the period of courtship, incubation, and rearing of the young until they are able to fly, and which extends to two months and a half, begin to disappear from the moment incubation has fairly begun, and at the time when the young leave the nest scarcely any remain, unless on the sides of the head. In autumn and winter the feathers of the head are similar to those of the neck, and the plumage in general has lost much of its vernal and aestival beauty. The entire crest also falls off in autumn. The white markings and the crest are renewed in the wild state about the end of February; but in birds kept in domestication rarely before May. The young do not exhibit the crest until the second spring, at which period, being yet destitute of white markings on the head and thighs, they might readily be mistaken for a different species, by a person unacquainted with their habits.

The singular fact that the young of some species of Cormorant have open nostrils until they are nearly half-grown, may surprise you as much as it surprised me. Having observed it in many individuals, I preserved one in spirits, and of it you will find a description beneath.

The Common Cormorant is rarely seen farther south than the extreme limits of Maryland; but from Chesapeake Bay eastward, it becomes more plentiful; and in severe winters, I have seen it exposed for sale in the New York market. They are abundant in winter around the islands of the Bay of Boston, and on the coasts of Massachusetts and Maine, where most of them remain during autumn, winter, and the early part of spring, as well as on the Bay of Fundy and along the shores of Nova Scotia. I am unable to say how far north they go beyond Labrador, to breed, or what may be the limits of their range on the St. Lawrence in autumn. I have never seen one on a tree, or on fresh water. The flesh of this species is dark, tough, and fishy, its eggs also do not furnish agreeable food, and it is seldom that either are eaten, even by epicures.

PHALACROCORAX CARBO, Bonap. Syn., p. 402.
CORMORANT, Nutt. Man., vol. ii. p. 479.

COMMON CORMORANT, Phalacrocorax Carbo, Aud. Orn. Biog., vol. iii. p. 458.

Male, 37, 62.

Ranges during winter southward to New York. Abundant from Massachusetts eastward. Breeds on high precipitous rocks, in Newfoundland, Labrador, and Baffin's Bay. Migratory.

Adult Male in March.

Bill about the length of the head, rather slender, somewhat compressed, straight, with the tip curved. Upper mandible with the dorsal line sloping and slightly concave, at the tip decurved, its ridge broad and rounded, and separated from the sides by a narrow groove, the sides erect, irregularly scaly, convex, the edges sharp and straight as far as the unguis, at the base a distinct horny plate, the unguis strong, convex above, incurved, acute. No external nostrils when full-grown. Lower mandible with the angle long and very narrow towards the end, filled by an extensible membrane, which extends a short way down the throat, its short dorsal line a little convex, then concave, the sides scaly, erect, and slightly convex, the edges sharp and inflected, the tip compressed and obliquely truncate.

Head rather large, oblong, narrowed before. Neck long and stout. Body rather full, depressed. Feet short, stout, placed far behind; tibia feathered in its whole length; tarsus very short, strong, much compressed, covered all round with scales, of which the outer are sub-hexagonal, the inner transversely elongated, the posterior very small and roundish. Toes all placed in the same plane, and connected by reticulated webs, covered above with very numerous oblique scutella; first toe smallest, fourth longest. Claws strong, curved, compressed, acute, that of the third toe pectinated on its inner edge.

Plumage of the head, neck, lower parts, and posterior portion of the back, glossy, blended, and silky; of the fore part of the back and wings compact, the feathers with loose glossy margins. The middle feathers of the occiput and hind neck are elongated, and those of the head and upper neck are intermixed with numerous linear feathers of a different colour, and erectile at will. Space around the eye, and to a large extent along the base of the bill, together with the small gular sac, bare. Wings rather small; primaries very strong, curved, rather narrow, tapering and obtuse, third longest, second almost as long, first little shorter; secondaries decurved, broad, broadly rounded, the inner broad and shorter. Tail small, much rounded, of fourteen narrow, rounded feathers, having extremely long shafts.

Upper mandible greyish-black, along the edges yellowish-white; lower yellowish-white at the base, dusky towards the end. Iris light bluish-green, margins of eyelids dusky. Bare space about the eye dull olive, below it bright red, the gular sac yellow. Feet and claws greyish-black. All the silky part of the plumage is black, glossed with deep greenish-blue; at the base of the gular sac is a broad gorgelet of white, and the linear interspersed feathers over the head and upper neck are white, there is also a large parcel of elongated white feathers on the side over the thigh. The feathers of the wings and part of the back are dull bluish-grey glossed with bronze, their fringe-like margins greenish-black. Primary quills greyish-black, secondary like the other feathers of the wing. Tail greyish-black. The shafts of all the feathers are black at the end, leaden-grey towards the base.

Length to end of tail 37 inches, to end of claws 36; to end of wings 32; extent of wings 62; wing from flexure 14; tail 6 1/2; bill along the ridge 3 5/12, along the edge of lower mandible 4 2/12; tarsus 2 1/4; outer toe 3 7/12, its claw (6 1/2)/12. Weight 7 1/2 lbs.

Female in July.

The female when old is similar to the male. In the state here represented, the plumage in general is similar, but the white feathers of the head and thighs are wanting. The bill, eyes and feet are coloured as in the male, as are the bare parts about the base of the bill, only the part under the eye which is bright red in the male, is bright yellow in the female.

Young birds unfledged.

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 apertures 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 oesophagus 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 coeca, 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 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 lbs. 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 1/2 long, (3 1/2)/12 in diameter, rounded, but not much enlarged at the extremity.

The oesophagus 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 rugae 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 coeca. The rectum is 7 inches long, its diameter for 4 1/2 inches is 7/12; the cloaca globular, 2 1/12 in diameter; the coeca 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 oasophagus 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.

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