“I was rather surprised to observe that this bird was not only entirely incapable of perching, but even of standing upright like birds in general, and as I have seen birds of this genus represented, unless by the aid of its wings. In standing, or rather sitting, the whole of the tarsus (commonly mistaken for the leg) rests on the ground, and it walks in the same awkward position, frequently being obliged to balance itself with its wings. By a more powerful exertion of its wings, however, it was enabled to run along on its toes in the same manner as it does over the surface of the waves. The absence of a hind toe, the nails being but slightly bent and flat, and perhaps I may add, its evidently being unaccustomed to this description of locomotion, seemed to be the causes of its helplessness on its feet.
“These birds have been numerous about us for some days past, and their coursing over the water with flitting wings remind me of the actions of butterflies about a pool. One of them was seen swimming, or at least resting, on the surface. We have seen this species very frequently, indeed almost daily, since leaving America, and scarcely any other sea-birds, except in the immediate vicinity of the islands. It would seem that it scarcely ever visits the land, except for the purposes of incubation, and there can hardly be a better comment on its untiring power of wing than the popular fable amongst seamen that it carries its egg and hatches its young while sitting in the water. It does not sail in the continued manner of the gulls and some other sea-birds, but moves by rapidly flexing its wings something like a bat, and was continually coursing around and in the wake of the vessel, generally in considerable numbers, during much the greater part of the time that the Expedition was in the Atlantic Ocean.”
The curious fact that this bird cannot stand upright we do not remember ever before having seen noticed. Of the specimen alluded to, Dr. Pickering gives notes of a minute and evidently very careful anatomical examination, which the limits of our present article will not allow us to insert. They are, however, confirmatory, in most respects, of the account of the anatomy of this species, given by Mr. Audubon, in Ornithological Biography, V., p. 645.
The bird before the reader in the present plate is an inhabitant of the Northern Pacific Ocean, and is an interesting addition to the ornithological fauna of the United States, made by the naturalists of the Exploring Expedition, under command of Captain Charles Wilkes, to which we have previously alluded. Though long known as a bird of the coasts of Asiatic Russia and of Russian America, it had never before been noticed on the more southern coast of Oregon, where it was found in large numbers by the Expedition, and specimens then obtained are now in the National Museum at Washington.
This bird was first noticed by the celebrated Pennant, in Arctic Zoology, Vol. II., p. 255, who called it the “Fork-tailed Petrel.” An accurate description is given by him, but no further account of it than merely stating “taken among the ice between Asia and America.” On the faith of this description, Gmelin, in Systema Naturæ, as cited below, gave the scientific name. Subsequently, Pallas mentions it as an inhabitant of the coasts of Unalaschka and of the Kurile Islands. It is also mentioned in the Zoology of the Voyage of the Sulphur, (London, 1844,) and very handsomely figured from specimens obtained at Sitka in Russian America.
To the journal of Dr. Pickering we have again to acknowledge our obligations for a notice of this bird. First recording its occurrence on the 26th of April, 1840, at sea, the distance from the coast of Oregon being about 200 miles, he subsequently mentions it under date of 29th of the same month, as follows:
“In sight of the coast of Oregon. Great numbers of the gray Thalassidroma are to-day flitting around and in the track of the vessel, very actively engaged in searching for particles of food thrown overboard. Generally, this bird reminds us of T. Wilsonii, but the wings seem longer, and its movements appear to be more rapid, and in fact more like that of the larger Petrels, (Procellaria.) It occasionally sails in its flight, but for the greater part moves by very rapidly flexing its wings in the same manner as the species mentioned.
“These birds proved not difficult to capture, and several specimens were taken with a hook and line. They would dive a foot or two after the bait, and made use of their wings in and under the water, from which they apparently had not that difficulty in rising observable in the Albatrosses. Though their powers of swimming seemed rather feeble, they alighted in the water without hesitation. The dead body of one of their companions being thrown overboard, they clustered around it with as much avidity as around any other food.
“The specimens obtained agree generally in color of plumage, being nearly a uniform pale gray, with the abdomen sometimes paler or nearly white, and generally showing a lighter bar across the wing, when expanded. Uttered a faint note when taken on board.”
At present we have no further information relating to this interesting species.