Part 280

"While this species is plainly of the Oriolus steeri type it differs in being larger, in the much darker and greener upper parts and under tail-coverts, in the darker throat and breast, in the wider black markings of abdomen, and in the reduced yellow tips of rectrices.

"O. assimilis is exceedingly common in the small amount of forest left in Cebu. It is a well-marked species and could not possibly be mistaken for O. steeri, being a much darker bird. The lack of the bright rump and under tail-coverts is an especially striking point of difference. Sixteen males average: Length, 225; wing, 120; tail, 89; culmen, 26; tarsus, 22.3; middle toe with claw, 23.8. Ten females, length, 217; wing, 118; tail, 87; culmen, 25.6; tarsus, 22.3; middle toe with claw, 23.3. Iris usually bright red, but in one case gray; legs and feet dark drab, nails black; bill light to dark reddish brown. Food worms, grubs, snails, and fruit." (Bourns and Worcester MS.)

715. ORIOLUS XANTHONOTUS Horsfield.

BLACK-HEADED ORIOLE.

Oriolus xanthonotus Horsfield, Trans. Linn. Soc. (1821), 13, 152; Sharpe, Cat. Birds Brit. Mus. (1877), 3, 213; Ibis (1888), 200; McGregor and Worcester, Hand-List (1906), 107.

Calamianes (Worcester); Palawan (Everett, Whitehead, Steere Exp., Bourns & Worcester, Celestino, White). Malacca, Java, Sumatra, Borneo.

Adult male.--Entire head, neck, chin, throat, and chest black; back, rump, tail-coverts, and crissum rich lemon-yellow; feathers of back with obscure dusky shaft-lines; basal feathers of crissum with mesial streaks of olive-green; lower breast, abdomen, sides, and flanks white with wide, black, mesial streaks; sides and flanks washed with yellow; breast also washed with yellow in some specimens; feathers of thighs black, tipped with light yellow; wings black; primaries edged with light gray; secondaries, tertials, and greater coverts narrowly edged with bright yellow; median coverts more widely edged with yellow; lesser coverts entirely yellow; inner webs of quills edged with pale yellow; under wing-coverts black, edged with yellow; axillars yellow; rectrices black, slightly fringed with yellow basally, widely tipped with yellow on inner webs, about 25 mm. on outermost pair and reduced to a mere trace on the middle pair; shafts of rectrices black above, brown below. A male measures: Wing, 111; tail, 75; culmen from base, 23; bill from nostril, 16; tarsus, 20.

Female.--Head, neck, sides of neck and ear-coverts black, streaked with olive-green; back yellow, but not so bright as in the male; jaw, chin, throat, and chest cinereous with whitish streaks; breast and abdomen like the male, but less heavily streaked with black; primaries more widely edged with pale gray than in the male; secondaries and tertials broadly edged with olive-green; primary-coverts and alula edged with gray; exposed edges of all the secondary-coverts olive-green; rectrices heavily washed with olive-green on outer webs; both webs of central pair nearly all olive-green; shafts yellow below. A female measures: Wing, 109; tail, 76; culmen from base, 23; bill from nostril, 16.5; tarsus, 21.

"Eight males average: Length, 197; wing, 114; tail, 77; culmen, 25; tarsus, 20.5; middle toe with claw, 22.3. Five females, length, 192; wing, 106; tail, 73; culmen, 23; tarsus, 20.5; middle toe with claw, 21.5. Iris deep red; legs and feet slaty blue, nails blackish; bill light reddish brown." (Bourns and Worcester MS.)

Family DICRURIDÆ.

Bill strong, culmen ridged and strongly curved; cutting edge curved with a notch near the tip; nostrils hidden by many soft, antrorse, frontal plumes, the anterior of which have long bristle-like shafts; rictal bristles long and stiff; wing long; first primary more than one-half the second, the latter much less than third; fourth and fifth practically equal and longest; tail long to very long, slightly to deeply forked; rectrices ten, the two outer pairs curved outward near the tips. Legs and feet stout; tarsus slightly longer than bill from nostril; bill, legs, and nails black in all the species.

Genera.

a1. Plumage mostly, or entirely, black; upper parts glossed with green or blue.

b1. Tips of outermost rectrices not curved upward; tail nearly square. ... Dicrurus (p. 702) b2. Tips of outermost rectrices curved upward, the webs more or less rotated about the shaft; tail decidedly forked ... Chibia (p. 705)

a2. Plumage almost entirely gray and cinereous, with neither blue nor green gloss; tail deeply forked ... Bhuchanga (p. 708)

Genus DICRURUS Vieillot, 1816.

Wing much longer than tail; tail slightly forked; rectrices broad, the outermost with very little if any upward curve at tip. Plumage mostly, or entirely, black, glossed with blue or green.

Species.

a1. Lower breast, abdomen, and crissum black, glossed with green or blue.

b1. Back strongly glossed with green ... balicassius (p. 703) b2. Back velvety black with little or no gloss.

c1. Smaller; wing, 130 to 135 mm.; tail, 112 to 115 ... striatus (p.704) c2. Larger; wing, 145 to 155 mm.; tail, 133 to 136 ... suluensis (p. 704)

a2. Lower breast, abdomen, and crissum white ... mirabilis (p. 705)

716. DICRURUS BALICASSIUS (Linnæus).

NORTHERN DRONGO.

Corvus balicassius Linnæus, Syst. Nat. ed. 12 (1766), 1, 157. Dicrurus balicassius Tweeddale, Trans. Zool. Soc. (1875), 9, 180, pl. 31, fig. 1; Sharpe, Cat. Birds Brit. Mus. (1877), 3, 230; Whitehead, Ibis (1899), 101 (song); McGregor and Worcester, Hand-List (1906), 107. Dicrurus balicassius mindorensis Mearns, Proc. U. S. Nat. Mus. (1909), 36, 447.

Ba-li-ca-si-ao, Filipino name.

Lubang (McGregor); Luzon (Meyer, Everett, Bourns & Worcester, Whitehead, McGregor, Bartsch); Marinduque (Steere Exp.); Mindoro (Steere Exp., Schmacker, Bourns & Worcester, Whitehead, McGregor, Mearns); Polillo (McGregor); Verde (McGregor.)

Adult (sexes alike).--Black, the exposed edges of the feathers glossed with steel-green which changes to dark purple in some lights; lores velvety black; feathers of throat and chest somewhat lanceolate; feathers of sides and flanks white or light gray basally; wing-lining and axillars glossy steel-blue. A male from Lubang Island measures: Length, 267; wing, 145; tail, 126; bill from nostril, 20; depth of bill at nostril, 10; tarsus, 23. A female from Bataan Province, Luzon, measures: Wing, 141; tail, 118; bill from nostril, 21; depth of bill at nostril, 11; tarsus, 24.