Family	THE DUSKY SHEARWATER. [Audubon's Shearwater.]
Genus	PUFFINUS OBSCURUS, Lath. [Puffinus lherminieri.]

On the 26th of June, 1826, while becalmed on the Gulf of Mexico, off the western shores of Florida, I observed that the birds of this species, of which some had been seen daily since we left the mouth of the Mississippi, had become very numerous. The mate of the vessel killed four at one shot, and, at my request, brought them on board. From one of them I drew the figure which has been engraved. The notes made at the time are now before me, and afford me the means of presetting you with a short account of the habits of this bird.

They skim very low over the sea in search of the floating bunches of marine plants, usually called the gulf weed, so abundant here as sometimes to occupy a space of half an acre or more. In proceeding, they flap their wings six or seven times in succession, and then sail for three or four seconds with great ease, having their tail much spread, and their long wings extended at right angles with the body. On approaching a mass of weeds, they raise their wings obliquely, drop their legs and feet, run as it were on the water, and at length alight on the sea, where they swim with as much ease as Ducks, and dive freely, at times passing several feet under the surface in pursuit of the fishes, which, on perceiving their enemy, swim off, but are frequently seized with great agility. Four or five, sometimes fifteen or twenty of these birds, will thus alight, and, during their stay about the weeds, dive, flutter, and swim, with all the gaiety of a flock of Ducks newly alighted on a pond. Many Gulls of different kinds hover over the spot, vociferating their anger and disappointment at not being so well qualified for supplying themselves with the same delicate fare. No sooner have all the fishes disappeared than the Petrels rise, disperse, and extend their flight in search of more, returning perhaps in awhile to the same spot. I heard no sound or note from any of them, although many came within twenty yards of the ship and alighted there. Whenever an individual settled in a spot, many others flew up directly and joined it. At times, as if by way of resting themselves, they alighted, swam lightly, and dipped their bills frequently in the water, in the manner of Mergansers.

I preserved the skins of the four specimens procured. One of them I sent to the Academy of Natural Sciences of Philadelphia, by Captain JOHN R. BUTLER, of the ship Thalia, then bound from Havana to Minorca. Two others were presented to my excellent friend Dr. TRAILL, on my first becoming acquainted with him at Liverpool.

I found the wings of this species strong and muscular for its size, this structure being essentially requisite for birds that traverse such large expanses of water, and are liable to be overtaken by heavy squalls. The stomach resembles a leather purse, four inches in length, and was much distended with fishes of various kinds, partially digested or entire. The oesophagus is capable of being greatly expanded. Some of the fishes were two and a half inches in length, and one in depth. The flesh of this Petrel was fat, but tough, with a strong smell, and unfit for food; for, on tasting it, as is my practice, I found it to resemble that of the porpoises. No difference is perceptible in the sexes.

While on board the United States revenue cutter Marion, and in the waters of the Gulf Stream opposite Cape Florida, I saw a flock of these birds, which, on our sailing among them, would scarcely swim off from our bows, they being apparently gorged with food. As we were running at the rate of about ten knots, we procured none of them. I have also seen this species off Sandy Hook.

PUFFINUS OBSCURUS, Bonap. Syn., p. 371.
DUSKY PETREL, Nutt. Man., vol. ii. p. 337.
DUSKY PETREL, Puffinus Obscurus, Aud. Orn. Biog., vol. iii. p. 620.

Male, 11, 26.

Abundant during summer in the Gulf of Mexico, and off the coast eastward to Georgia. Some wander as far as Long Island.


Adult Male.

Bill about the length of the head, straight, somewhat cylindrical, the tips curved. Nostrils tubular, separate, inclosed in a horny sheath, and dorsal, the outline straight, curved on the unguis, the sides nearly erect, convex, the edges sharp, hard, and inflected, the tip decurved, strong. Lower mandible straight, the angle very narrow and extending nearly to the tip, the dorsal line beyond it decurved, the sides convex and inclining inwards, the edges sharp and inflected.

Head of moderate size. Neck of ordinary length; body ovate, Feet stout; tibia bare a short way above the joint; tarsus of moderate length, rather stout, reticulate; hind toe a very slight knob, with a small conical claw; fore toes long, slender, connected by reticulated webs with concave margins, the outer toe slightly longer than the third. Claws small, slightly arched, compressed, obtuse.

Plumage soft, full; the feathers rounded, those of the back and wing rather compact. Wings long; primaries tapering, rounded, the first longest, the rest rapidly graduated; secondaries of moderate length, rounded. Tail rather short, much rounded, of twelve feathers.

Bill light blue, the tips black, mouth light blue. Edges of eyelid light blue, iris bluish-black. Outside of tarsus and toes indigo-black, inside and webs pale yellowish-flesh-colour; claws bluish-black. The upper parts are sooty-black, the lower pure white.

Length to end of tail 11 inches, to end of wings 10 1/2, to end of claws 11 1/4; extent of wings 26 1/2; bill along the back 1 4/12, along the edge of lower mandible 1 3/4; tarsus 1 1/2; outer toe 2, its claw (2 1/2)/12.