Petrel, the common name of the web-footed oceanic birds constituting the subfamily procellarinm, characterized by tubular nostrils, placed on the basal portion of the culmen and opened in front; the beak as long as the head, straight, more or less compressed, grooved as if composed of several pieces, with the tip strong, arched, suddenly hooked, and acute. The best known genera are procellaria (Linn.), the petrels proper, and thalassidroma (Vigors), the stormy petrels. The general form of the body is like that of the gulls, but the feet have a very rudimentary hind toe, and the beak is very different, the apical being distinctly separated from the basal portion; the habits also are like those of the gulls, but more oceanic, as they pass most of their lives in skimming over the surface of the waves; they rarely visit the shore except for breeding, and then select rocky shores, depositing their eggs on the bare rock. They have a habit of running with closed wings upon the surface of the waves. The flight is rapid, powerful, and continuous, the same birds following vessels for many successive days; they sail along with extended wings, without flappings, and with apparently little motion; the higher the wind and the more agitated the sea, the more abundant are these birds, as at such times the crustaceans, mollusks, and other marine animals upon which they principally feed are most easily obtained. - In the genus procellaria the wings are long and pointed, the first quill the longest; the tail moderate and rounded, tarsi shorter than the middle toe, toes long and fully webbed and the lateral ones margined externally, the hind toe a mere triangular claw.

The giant petrel (P. gigantea, Gmel.; genus ossifraga, Homb. and Jacq.) is about 3 ft. long and 7 ft. in alar extent, at a distance resembling a small albatross; the plumage is dense, full, and elastic, and the head is wholly feathered; the color above is brownish gray mottled with dusky white, the wings and tail dusky brown; lower parts white; bill, legs, and feet yellow. Common in the southern ocean, it is sometimes seen on the Pacific coast of North America as far up as Columbia river in spring and summer; it is very rapacious, attacking and tearing to pieces the smaller petrels and young gulls; it lays its eggs on the sandy shores of the Falkland islands, where it occurs in immense numbers; the young are fed with oily matters which the parents eject from the stomach for the purpose. Other species found on the American coast are the Pacific, slender-billed, fulmar, and tropical petrels, respectively the P. pacifica, tenuirostris, glacialis, and rne-ridionalis, the first two found on the Pacific, and the last two on the Atlantic coast. (See Fulmar.) The pintado petrel, or Cape pigeon (P. Capensis, Linn.; genus daption, Steph.), is about 15 in. long; the general color is white above, varied with brown; the upper part of head and hind neck plumbeous black, smaller wing coverts the same, tipped with brown, the larger white margined with black; primaries white on the inner web and black on the outer; secondaries and tail white with dark tips; lower parts white; bill black.

This species is abundant in the southern ocean, with the albatross and other petrels; it has been seen on the coast of California. More than 20 other species are described. - In the genus thalassidroma the bill is shorter and more slender and weak; the nostrils open by a single tubular aperture, as in the preceding genus; the second quill is the longest, the tail more or less forked, the legs long and slender, with an extensive bare space on the tibia, tarsi longer than the middle toe, and the hind toe a small claw. The species, about a dozen, are small, and inhabit the surface of the sea in both hemispheres, skimming lightly and irregularly over the waves, floating upon them, or running along the tops; they follow vessels for great distances, feeding upon the greasy matters thrown overboard and upon minute marine animals; they are dark-colored, more or less marked with white, and. are popularly called Mother Carey's chickens and sometimes sea swallows. The common stormy petrel or Mother Carey's chicken (T. pelagica, Vig.) is about 5| in. long, with an alar extent of 13 1/2 in.; the bill and feet are black; the color is grayish black above, tinged with brown; below sooty brown; secondary coverts margined with grayish white, and quills black; rump and upper tail coverts white with black shafts, the tail coverts broadly tipped with black.

They are thought by sailors to forebode stormy weather, and are therefore dreaded and scrupulously unmolested; they occur in most parts of the temperate Atlantic, and are common about the banks of Newfoundland with the other species. They breed on rocky shores and islands in the N. Atlantic, on St. Kilda, and the Shetland islands; in the latter they begin to lay toward the end of June, depositing a single egg in a nest made of plants and earth, carefully concealed, sometimes at a depth of 3 or 4 ft., under the stones on the beaches; they remain quiet by day, becoming active about twilight; the eggs are 1 1/8 by 3/4 in., white, with minute dull red dots at the larger end. According to Briinnich, this bird becomes so fat that the inhabitants of the Faroe islands string it to a wick, and use it as a lamp. Other species of this genus are found in America. - In the genus pelecanoides (Lacep.) the bill is shorter than the head, broad, depressed, and swelled at the sides; beneath the bill is a membranous pouch capable of extension; nostrils 'opening by two tubular apertures; wings very short, as are the tarsi and tail; toes long, the hind one wanting.

A few species are described, inhabiting the coasts of New Zealand, Australia, and the extreme parts of South America; they are seen in troops, and dive very frequently, probably in search of small fish; they are rather poor fliers, compared with other petrels. - In the genus prion (Lacep.) the bill is longer, depressed, with nearly straight cul-men, sides dilated near the base and beset posteriorly with fine parallel laminae; nostrils with two openings, short and elevated; the hind toe a mere claw. The broad-billed petrel (P. mt-tatus, Lacep.), found between lat. 35° and 70°' S., is bluish ash above, with tips of quills and wing coverts black; some of the characters of the bill resemble those of the fishing ducks. It is wild and solitary, a rapid flier, and constantly on the wing; the nests are made in society, in burrows about a yard deep, excavated in the sides of hills near the sea; the eggs are white, elongated, like those of a pigeon. - For the genus puffinus (Briss.) see Shearwater.

Pintado Petrel (Procellaria Capensis).

Stormy Petrel (Thalassidroma pelagica).