Part 37

Ga-bi-o'-ta, general name for gulls and terns.

Agutaya (McGregor); Balabac (Steere); Bantayan (McGregor); Bohol (Everett, McGregor); Calamianes (Bourns & Worcester); Caluya (Porter); Cebu (Bourns & Worcester, McGregor); Cuyo (McGregor); Guimaras (Bourns & Worcester); Leyte (Everett); Luzon (Bourns & Worcester); Masbate (Bourns & Worcester); Mindanao (Murray, Koch & Schadenberg, Steere Exp., Bourns & Worcester); Mindoro (Porter); Negros (Bourns & Worcester, Keay); Palawan (Whitehead, Platen, Bourns & Worcester, White); Panay (Bourns & Worcester); Pata (Mearns); Romblon (Bourns & Worcester, McGregor); Samar (Bourns & Worcester); Sibuyan (Bourns & Worcester); Siquijor (Bourns & Worcester, Celestino); Sulu (Bourns & Worcester); Tablas (Bourns & Worcester); Tawi Tawi (Bourns & Worcester). Liu Kiu Islands and Northern China Sea.

"Adult male in full breeding plumage (type).--Forehead, cheeks, lores, ear-coverts, neck all round, and whole under parts, including lining of wing and bend of wing, pure white; crown and long occipital crest glossy black; mantle, wings, rump, upper tail-coverts, and upper surface of middle rectrices dark smoke-gray, darkest on wings and middle of back, where the color is almost mouse-gray; primary quills white; first primary with outer web, a band along quill on inner web and tip blackish, with a silvery suffusion which is most marked toward center of feather; broad outer margin of inner web, below the black tip, white; second primary similar but black tip deeper in color and extending a short distance down outer margin of inner web, thus inclosing the white of inner web for a short distance; third, fourth, and fifth primaries like second, but black tip gradually growing deeper in color; outer rectrices above pale smoke-gray at tips and along shafts, pale grayish white toward base; second and third rectrices darker on the outer webs and at tip and whitish toward base of inner webs. Bill in dried specimen, dull yellow clouded with olive toward base; feet and tarsi blackish. Wing, 344; tail, 178; tarsus, 28; culmen, 62." (Bangs.)

"Very common throughout the group, especially abundant about the native fish-pens." (Bourns and Worcester MS.)

This is much the largest tern found in the Philippines. Rather local in its distribution but usually found not far from fish-corrals or where schools of small fishes appear near the surface of the water.

Philippine records of this species are usually recorded under Sterna bergii, but the specimens probably belong to the variety S. bergii boreotis. The question can not be cleared up at present.

81. STERNA ANÆSTHETA Scopoli.

PANAYAN TERN.

Sterna anæstheta Scopoli, Del. Flor. et Faun. Insubr. (1786), 1, 92; Saunders, Cat. Birds Brit. Mus. (1896), 25, 101; Sharpe, Hand-List (1899), 1, 136; Oates, Cat. Birds' Eggs (1901), 1, 190; McGregor and Worcester, Hand-List (1906), 20. Worcester, Phil. Jour. Sci. (1907), 2, sec. A, 275, pl. 1 (nesting place).

Didicas Rocks (Worcester); Panay (Sonnerat). African and Indian seas to China, Japan, Moluccas, northern Australian, Pacific Islands; Gulf of Mexico, Western Indies.

"Adult in breeding plumage.--Loral stripe black; upper forehead, crown, and nape black; shoulders slate-gray, passing into dark grayish brown on mantle; no visible white on secondaries; primaries umber-brown, shafts black, the 'wedges' on inner webs very narrow and not sharply defined; rump and principal tail-feathers grayish brown like the mantle, but the streamers white on outer and upper portions of inner webs, and the next pair of rectrices whitish at their bases; abdomen and breast grayish white; under wing-coverts and throat pure white. Bill, tarsi, and toes black, the inner webs of the latter considerably excised. Length, 355 to 380; culmen, 45; wing, 262; tail, 190; depth of fork, 102; tarsus, 20; middle toe with claw, 30. The sexes are alike in plumage.

"Adult in winter plumage.--Similar to the above, but the lores and crown mottled with white for a short time.

"Immature.--Generally similar, but with more white on the head; whitish tips to the feathers of the back, which, when fresh, are somewhat gray; a dark line along upper wing-coverts, and less white on outer rectrices. Full plumage is not attained until the bird is at least two years old.

"Young.--Head streaked and mottled with brownish black; feathers of upper parts dark brown with rufous tips, which subsequently become paler, approaching white, and finally wear away; under parts grayish white. Bill and toes brownish." (Saunders.)

82. STERNA FUSCATA Linnæus.

SOOTY TERN.

Sterna fuscata Linnæus, Syst. Nat. ed. 12 (1766), 1, 228. Sterna fuliginosa Saunders, Cat. Birds Brit. Mus. (1896), 25, 106; Sharpe, Hand-List (1899), 1, 136; Oates, Cat. Birds' Eggs (1901), 1, 191; McGregor and Worcester, Hand-List (1906), 21.

Siquijor (Bourns & Worcester). Tropical and juxtatropical seas of the world.

"Adult in breeding plumage.--Similar to S. anæstheta; but larger, white frontal-band and superciliary stripe broader, the latter oblique and not reaching beyond eye, from which it is separated by a narrow continuation of the black loral stripe; upper surface sooty black, the wedges on inner webs of primaries a trifle paler than the rest; streamers dull white on the outer webs, remaining tail-feathers sooty black; under tail-coverts, abdomen, and flanks grayish white; breast and throat white. Bill and feet black with a slightly reddish tinge, the web between middle and inner toe nearly full, and far less excised than in S. anæstheta. Length, about 430; culmen, 53; wing, 298; tail, about 190; depth of fork, 102; tarsus, 23; middle toe with claw, 28.

"Adult in winter.--Like the above, with white flecks on the lores and crown.

"Immature.--Brownish black above, darker on the upper wing-coverts; outer tail-feathers nearly as sooty black as the rest of the rectrices, except toward the tips; tarsi and toes reddish brown.

"Nestling and young.--The chick when about three days old is streaked with grayish brown and dull white on the upper surface, darkest on the forehead, and chiefly stone-white below; when half fledged, the feathers of the mantle are blackish, with broad white tips, which gradually wear down. When the bird is fully fledged these white tips are much narrower, the feathers of the upper parts are sooty brown, and the under parts are also somewhat paler brown, becoming lighter toward the vent. (In S. anæstheta the under parts are whitish). Bill and feet reddish brown." (Saunders.)

83. STERNA SINENSIS Gmelin.

WHITE-SHAFTED TERN.

Sterna sinensis Gmelin, Syst. Nat. (1788), 1, pt. 2, 608. Saunders, Cat. Birds Brit. Mus. (1896), 25, 113; Sharpe, Hand-List (1899), 1, 136; Oates, Cat. Birds' Eggs (1901), 1, 192; McGregor and Worcester, Hand-List (1906), 21.

Luzon (Whitehead); Mindanao (Steere Exp.); Mindoro (Bourns & Worcester); Palawan (Whitehead). Chinese and Indian seas to Australia.

"Adult male in breeding plumage.--Lores black from base of bill to eye; forehead as far as a little beyond the top of eye white; crown and nape black; mandible pearl-gray; secondaries bordered with grayish white; shafts of primaries pure white in the outer, and pale gray in the upper ones; outer web of the outer primary and a broad line next the shaft on its inner web dark gray; on the succeeding primaries paler gray; upper portions and edges of inner webs white; rump pearl-gray; tail and under parts white. Bill gamboge-yellow, tipped with black; tarsi and feet orange-yellow. Length, 280 when the streamers are fully developed; culmen, 35; wing, 188; tail, 145; depth of fork, 86; tarsus, 16; middle toe with claw, 20.

"Adult female.--Slightly smaller than the male and with less developed tail-streamers.