Ornithological biography, Vol. 4 (of 5)

by John James Audubon

The trachea, Fig. 1. k, l, is very wide, flattened, its rings unossified, its length 2 9/12 inches, its breadth 3 twelfths, nearly uniform, but at the lower part contracted to 2 twelfths. There are 75 rings, with 5 inferior blended rings, which are divided before and behind. The bronchi, Fig. 1. m, m, are wide and rather elongated, with about 25 half rings. The contractor muscles are extremely thin, the sterno-tracheal slender; there is a pair of inferior laryngeal attached to the first bronchial rings.

The above account of the digestive organs of this bird will be seen to be very different from that given by Sir Everard Home, who has, in all probability, mistaken the species. “There is still,” says he, “one more variety in the structure of the digestive organs of birds, that live principally upon animal food, which has come under my observation; and with an account of which I shall conclude the present lecture. This bird is the Alea Alle of Linnæus, the Little Auk. The termination of the œsophagus is only known by the ending of the cuticular lining, and the beginning of the gastric glands; for the cardiac cavity is one continued tube, extending considerably lower down in the cavity of the abdomen, and gradually enlarging at the lower part; it then turns up to the right side, about half-way to the origin of the cavity, and is there connected to a small gizzard, the digastric muscle of which is strong, and a small portion of the internal surface on each side has a hard cuticular covering. The gastric glands at the upper part are placed in four distinct longitudinal rows, becoming more and more numerous towards the lower part of the cavity, and extend to the bottom, where it turns up. The extent of the cavity in which the gastric glands are placed, exceeds any thing met with in the other birds that live upon fish; and the turn which the cavity takes almost directly upwards, and the gizzard being at the highest part instead of the lowest, are peculiarities, as far as I am acquainted, not met with in any other birds of prey. This mechanism, which will be better understood by examining the engraving, makes the obstacles to the food in its passage to the intestines unusually great; and enables the bird to digest both fishes and sea-worms with crustaceous shells. It appears to be given for the purpose of economizing the food in two different ways,—one retaining it longer in the cardiac cavity, the other supplying that cavity with a greater quantity of gastric liquor than in other birds. This opinion is further confirmed by the habits of life of this particular species of bird, which spends a portion of the year in the frozen regions of Nova Zembla, where the supplies of nourishment must be both scanty and precarious.”

With respect to this statement and the reasonings founded upon it, it will be seen from the description and accompanying figures above, taken directly from nature, and without the least reference to the dissections or theories of any person, that the œsophagus and stomach of the Little Auk or Guillemot, Alca Alle of Linnæus, are very similar to those of other Auks, Guillemots, Divers, and fish-eating birds in general. The cardiac or proventricular cavity forms no curve; and the gizzard with which it is connected, is not small, nor has it merely a small portion of the internal surface on each side covered with a hard cuticular lining; for the epithelium covers its whole surface, and is of considerable extent. The gastric glands are not at all disposed as represented by Sir E. Home, but are aggregated in the form of a compact belt half an inch broad, Fig. 2. b, c. As to the ingenious reasoning by which the economy of the Little Auk is so satisfactorily accounted for, it is enough here to say, that having no foundation, it is of less than no value. But were there such a curvature as that in question, there could be no propriety in supposing that it presented any great obstacle to the passage of the food, or retained it longer than usual. Nor is the statement as to scanty and precarious supply of nourishment correct; for the Arctic Seas, to which this bird resorts in vast numbers, are represented by navigators as abounding in small crustacea, on which chiefly the Little Auk feeds, and that to such an extent as to colour the water for leagues. Besides, if there were such a scarcity of food in Nova Zembla, why should the birds go there? In short, the whole statement is incorrect; and the many compilers, from Dr Carus to the most recent, who have pressed it into their service, may, in their future editions, with propriety leave it out, and supply its place with something equally ingenious.

The egg of this species measures one inch and nearly five-eighths in length, one inch and an eighth in its greatest breadth. It is remarkably large for the size of the bird, and of a dull uniform pale greenish-blue.

LEAST PETREL.

Thalassidroma pelagica, Leach.
PLATE CCCXL. Male and Female.

In August 1830, being becalmed on the banks of Newfoundland, I obtained several individuals of this species from a flock composed chiefly of Thalassidroma Leachii, and Th. Wilsoni. Their smaller size, and the more rapid motions of their wings, rendered them quite conspicuous, and suggested the idea of their being a new species, although a closer inspection shewed them to belong to the present. In their general manners, while feeding, floating on the water, or rambling round the boat in which I went in pursuit of them, they did not differ materially from the other species. Their flight, however, was more hurried and irregular, and none of them uttered any note or cry, even when wounded and captured. I have been assured that this bird breeds on the sandy beaches of Sable Island on the coast of Nova Scotia; but not having had an opportunity of visiting it, or any other breeding place, I here present you with Mr Hewitson’s observations on this subject.

“In an excursion,” says this amiable and enterprising naturalist, “through the Shetland Islands during the present summer, in search of rarities for this work (the British Oology), I had the very great satisfaction of seeing and taking many of these most interesting birds alive; they breed in great numbers on several of the islands, principally upon Foula, the north of Hunst, and upon Papa, and Oxna, two small islands in the Bay of Scalloway; the last of these I visited on the 31st of May in hopes of procuring their eggs (it being the season in which most of the sea-birds begin to lay); but in this I was disappointed; the fishermen who knew them well by the name of Swallows, assured me that my search would be quite useless, that they had not yet “come up from sea,” and so it proved. Sixteen days after this (June 16th and three following days) I was at Foula, but was alike unsuccessful, the birds had arrived at their breeding places, but had not yet begun laying their eggs; numbers of them were sitting in their holes, and were easily caught; one man brought me about a dozen tied up in an old stocking, two of which I kept alive in my room for nearly three days, and derived very great pleasure from their company; during the day they were mostly inactive, and after pacing about the floor for a short time, poking their head into every hole, they hid themselves between the feet of the table and the wall; I could not prevail upon them to eat any thing, though I tried to tempt them with fish and oil; their manner of walking is very light and pleasing, and differing from that of every other bird which I have seen; they carry their body so far forward and so nearly horizontal, as to give them the appearance of being out of equilibrium. In the evening, toward sun-set, they left their hiding places, and for hours afterwards, never ceased in their endeavours to regain their liberty; flying round and round the room, or fluttering against the windows; when flying, their length of wing, and white above the tail, gives them a good deal the appearance of our House-Martin. I went to bed and watched them in their noiseless flight long ere I fell asleep, but in the morning they had disappeared; one had fortunately made its escape through a broken pane in the window which a towel should have occupied, the other had fallen into a basin, full of the yolks of eggs which I had been blowing, and was drowned. I regretted much the fate of a being so interesting, by its very remarkable, wandering, solitary, and harmless life. Before leaving Shetland I again visited the island of Oxna, and though so late as the 30th of June, they were only just beginning to lay their eggs. In Foula they breed in the holes in the cliff, at a great height above the sea; but here under stones which form the beach, at a depth of three or four feet, or more, according to that of the stones; as they go down to the earth, beneath them, on which to lay their eggs. In walking over the surface, I could hear them, very distinctly, singing in a sort of warbling chatter, a good deal like swallows when fluttering above our chimneys, but harsher; and in this way, by listening attentively, was guided to their retreat, and, after throwing out stones as large as I could lift on all sides of me, seldom failed in capturing two or three seated on their nests, either under the lowest stone or between two of them. The nests, though of much the same materials as the ground on which they were placed, seem to have been made with care; they were of small bits of stalks of plants, and pieces of hard dry earth. Like the rest of the genus, the Stormy Petrel lays invariably one egg only. During the day-time they remain within their holes; and though the fishermen are constantly passing over their heads (the beach under which they breed being appropriated for the drying of fish), they are then seldom heard, but toward night become extremely querulous; and when most other birds are gone to rest, issue forth in great numbers, spreading themselves far over the surface of the sea. The fishermen then meet them very numerously; and though they have not previously seen one, are sure to be surrounded by them upon throwing pieces of fish overboard.”

The egg measures one inch and an eighth in length, six and a half eighths in breadth, is nearly equally rounded at both ends, rather thick-shelled, and pure white, but generally with numerous minute dots of dull red at the larger end, sometimes forming a circular band.

Procellaria pelagica, Linn. Syst. Nat. vol. i. p. 212.—Lath. Ind. Ornith. vol. ii. p. 826.