Part 78

"Young in down.--Head, neck, upper back, and under parts covered with white down, amongst which the plumage of the immature is more or less visible; quill- and tail-feathers half grown, pointed and narrowly margined at the extremity with pale brownish white; scapulars and wing-coverts much like those of the adult, but fringed externally with brown. Length, 724." (Grant.)

"Exceedingly abundant about Lake Naujan in Mindoro, where it breeds. Rarer about fresh-water streams in the interior of that island. Not met with by us outside of Mindoro.

"Always swims with its body entirely immersed, and can remain under water an incredibly long time. Flies with difficulty when it first rises from water. Makes straight for some good roosting place, preferably a stump or log in the edge of the water, where it alights, turns its back to the sun, spreads its wings, and remains until thoroughly dry. When dry it flies rapidly, and may often be seen during the heat of the day soaring at a considerable height." (Bourns and Worcester MS.)

"Very abundant on the upper waters of the Rio Grande de Cagayan in Isabela Province, and on the upper Agusan River and its lake system in Mindanao." (Worcester.)

The Indian darter is fairly abundant along the Baco River in Mindoro and on the Cagayan River in the vicinity of Aparri, Luzon. Clemens collected specimens on Lake Lanao, Mindanao.

Family SULIDÆ.

Bill stout and pointed, tapering gradually, the tip slightly curved but never hooked; a groove along each side of culmen; nostrils completely closed in adults; wings long and pointed, first primary longest; tail long and wedge shaped; tarsus short and stout; outer and middle toes nearly equal; claw of middle toe broad and pectinate.

Genus SULA Brisson, 1760.

Characters same as those given for the Family.

Species.

a1. Upper parts, head, and neck mostly pure white (adult). ... piscator (p. 204) a2. Upper parts uniform deep sooty brown.

b1. Breast and belly pure white (adult). ... leucogastra (p. 205) b2. Breast and belly light brown (immature).

c1. Outer webs of flight feathers washed with hoary gray. ... piscator (p. 204) c2. Outer webs of flight feathers dark brown. ... leucogastra (p. 205)

168. SULA PISCATOR (Linnæus).

RED-LEGGED BOOBY.

Pelecanus piscator Linnæus, Syst. Nat. ed. 10 (1758), 1, 134. Sula piscator Grant, Cat. Birds Brit. Mus. (1898), 26, 432; McGregor and Worcester, Hand-List (1906), 39. Sula piscatrix Sharpe, Hand-List (1899), 1, 237; Oates, Cat. Birds' Eggs (1902), 2, 210.

Mindanao (Steere Exp.). Oceania, southern Atlantic, Indian and Australian seas.

"Adult.--General color pure white; primaries, primary-coverts, outer webs and tips of secondaries, and secondary-coverts hoary gray, inclining to blackish on outermost quills in freshly molted birds, and to blackish in worn specimens; chin and upper part of throat naked, the feathers ending in a straight line across throat; tail composed of fourteen, or sometimes sixteen feathers. Iris gray; bill grayish blue, shading into pink or reddish toward the base; naked skin round eye blue; gular pouch dark slate or black; legs and feet vermilion, red or dark pink, almost magenta.

"Adult male.--Length, about 750; culmen from feathers on forehead, 89; wing, 394; tail, 10 to 28; tarsus, 35.

"Adult female.--Length, about 710; culmen from feathers on forehead, 81 to 88; wing, 373 to 375; tail, 208 to 210; tarsus, 35.

"Immature in first plumage.--Entire plumage above and below brown, lighter on breast and belly; primaries and secondaries and their coverts like those of the adult, but the inner webs of the secondaries black. Cutting edges of the mandible sometimes serrated, and the inner margin of the middle claw pectinate. Bill bluish pink, the latter predominating toward the base; naked skin round eye dark leaden hue; gular pouch flesh-colored.

"More adult specimens (perhaps in the plumage of the second year) head, neck, and under parts white; back, wings, and tail brown as in the immature; middle tail-feathers dark, brownish gray toward the base, shading into white toward the extremity.

"A still more adult bird has a large amount of white or partially white feathers mixed with the brown of the back and wings.

"I should imagine that the fully adult plumage is not attained until the third or perhaps the fourth year. This species may be recognized in all stages of plumage by the hoary gray appearance on the outer webs of the quills." (Grant.)

169. SULA LEUCOGASTRA (Boddaert).

BROWN BOOBY.

Pelecanus leucogaster Boddaert, Tabl. Pl. Enl. (1783), 57. Sula sula Grant, Cat. Birds Brit. Mus. (1898), 26, 436; Sharpe, Hand-List (1899), 1, 237; McGregor and Worcester, Hand-List (1906), 40; Oates, Cat. Birds' Eggs (1902), 2, 212; Worcester, Phil. Jour. Sci. (1907), 2, sec. A, 275. pl. 1 (Didicas Rocks). Sula leucogaster Blanford, Fauna Brit. Ind. Bds. (1898), 4, 346, fig. 80 (head). Sula leucogastra A. O. U. Committee, Auk (1908), 25, 359.

Batan (McGregor); Calayan (McGregor); Didicas Rocks (Worcester); Dinagat (Everett); Luzon (McGregor); Mindanao (Cuming, Everett). Tropical Atlantic, Indian, Australian, and Pacific Oceans.