Adult.—Above brown; head, neck, and mantle with an ashy blue wash, basal portion of feathers white or with one or two large white spots; back, rump, and tail-coverts brown without hidden white spots; sides of head brown; chin and throat white with a narrow median brown line; remainder of under parts rich reddish brown or rusty chestnut, most intense and uniform on breast and sides, each feather barred with dark brown and white, the barred portion hidden, more or less, by the wide reddish brown tips; crissum white; wings brown, primaries barred with gray on distal part of inner webs and with ochraceous on basal part; secondaries barred with ochraceous on inner webs; scapulars with two or more large white spots, all concealed; axillars and wing-lining faint ochraceous, barred with brown; tail brown, crossed by five darker brown bars.
Male from Benguet, Luzon.—Length, 254; wing, 156; tail, 114; culmen from base, 18; tarsus, 48; middle toe with claw, 35.
Female from Benguet, Luzon.—Bill black, bluish at base, cere pea-green; iris and eyelids bright yellow; skin about eye and base of bill dull green; nails very dark brown; legs and feet light yellow. Length, 310; wing, 185; tail, 140; culmen from base, 20; tarsus, 53; middle toe with claw, 45.
Breeding female from Cebu.—Bill horn-blue; cere waxy green; iris and eyelids chrome-yellow; legs greenish yellow; nails blackish. Length, 312; wing, 179; tail, 136; culmen from base, 20; tarsus, 56; middle toe with claw, 44.
Immature male.—Upper parts earthy brown; head and mantle slightly bluish ash; feathers of wings, mantle, rump, and upper tail-coverts edged with rusty brown; median line on throat incomplete; breast and abdomen white with very wide, seal-brown, shaft-stripes; sides and flanks with some reddish brown cross-bars; thighs white, barred with brown; wing-lining ochraceous with large blackish brown spots.
“Accipiter manillensis is, I think, subspecifically distinct from typical A. virgatus, and Mr. Whitehead having, in addition to the Museum series, now obtained three adult females, we have a fair number of skins for comparison.
“Adult female.—Differs from the female of A. virgatus in having the chest, breast, and sides nearly uniform light red in the most adult birds, while in somewhat younger examples the middle of the breast shows distinct cross-bars of reddish brown and white; the under surface on the quills washed with rufous. Wing, 175 to 178; tail, 137 to 139; tarsus, 52 to 53.
“Adult male.—Like the male of A. virgatus. Wing, 152 to 155; tail, 122 to 124; tarsus, 51.” Grant, Ibis, (1896), 109.
I have found considerable difficulty in identifying members of the genus Accipiter from the Philippines and the preceding descriptions will require revision when more specimens shall have been collected. With some hesitation I have placed A. stephensoni as a synonym under A. manillensis instead of under A. gularis.