Nisus manillensis Meyen, Beitr. (1834), 694, pl. 9.
Accipiter virgatus Sharpe, Cat. Birds Brit. Mus. (1874), 1, 150
(part).
Accipiter manillensis Grant, Ibis (1897), 212; Sharpe, Hand-List
(1899), 1, 254; McGregor and Worcester, Hand-List (1906), 41.
Accipiter stevensoni Tweeddale, Proc. Zool. Soc. (1878), 938,
pl. 57.
Cebu (McGregor); Guimaras (Bourns & Worcester); Leyte (Whitehead);
Luzon (Heriot, Whitehead, McGregor); Mindanao (Everett, Bourns &
Worcester, Celestino, Goodfellow); Mindoro (Everett, Porter);
Negros (Steere).
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.
Subfamily AQUILINÆ.
Genera.
a1. Tail nearly square or slightly forked; or, if decidedly graduated,
the wing over 350 mm.
b1. Bill without a distinct tooth on its cutting edge; first primary
much shorter than second or third.
c1. Feathers of lores and circumocular region not scale-like;
loral bristles present.
d1. Tail not forked.
e1. Tarsus covered to the toes with short thick-set feathers.
f1. Distance between tips of primaries and secondaries much
greater than length of tarsus. ... Lophotriorchia (p. 223)
f2. Distance between tips of primaries and secondaries much
less than length of tarsus. ... Spizaëtus (p. 224)
e2. Tarsus not feathered to the toes.
f1. Nostril a vertical slit; bill extremely
compressed; culmen curved throughout its length; size
large. ... Pithecophaga (p. 226)
f2. Nostril round or oval; bill not greatly compressed.
g1. A full, circular, occipital crest; plumage of under
parts with numerous round white spots. ... Spilornis
(p. 227)
g2. Crest scanty or wanting; plumage not spotted.
h1. Back of tarsus covered with hexagonal scales; wing,
330 to 380 mm.
i1. Tarsus with hexagonal scales in front; wing falling
far short of tip of tail; lower plumage whitish,
barred or spotted with brown. ... Butastur (p. 230)
i2. Tarsus with transverse scutes in front; wing very
long, extending beyond end of tail; plumage chestnut
and white in adult. ... Haliastur (p. 233)
h2. Back of tarsus with large transverse plates; wing
over 500 mm. ... Haliæetus (p. 232)
d2. Tail slightly forked, middle feathers about 10 mm. shorter
than outermost; unfeathered portion of tarsus covered with
small round scales. ... Elanus (p. 234)
c2. Feathers of lores and large circumocular area short and
scale-like; no hairs about the bill; tarsus covered with long
feathers for more than half its length, unfeathered portion with
small hexagonal scales on all sides. ... Pernis (p. 235)
b2. Bill with one or two well-developed teeth on its cutting edge;
first primary nearly as long as second and usually longer than third.
c1. Head crested; tarsus feathered for half its length. ... Baza
(p. 236)
c2. Head not crested; tarsus feathered at base only and covered
with hexagonal scales.
d1. No tubercle in nostril; length less than 200
mm. ... Microhierax (p. 238)
d2. A tubercle in center of nostril; length more than 250
mm. ... Falco (p. 239)
a2. Tail distinctly graduated; bill shorter; feet smaller and weaker;
middle toe without claw two-thirds to three-fourths of tarsus; wing
less than 250 mm. ... Cerchneis (p. 243)
Genus LOPHOTRIORCHIS Sharpe, 1874.
Cutting edge of bill sinuate; a narrow occipital crest about 60
mm. long; wing moderate in length; first primary very short; third and
fourth subequal; inner web of first four quills abruptly and deeply
cut; legs closely feathered to base of toes which are covered with
small hexagonal scales; claws strong and curved.