Artamides sumatrensis Sharpe, Cat. Birds Brit. Mus. (1879), 4,
12 (part).
Graucalus sumatrensis difficilis Hartert, Novit. Zool. (1895),
2, 470.
Artamides difficilis Sharpe, Hand-List (1901), 3, 287.
Artamides dificilis McGregor and Worcester, Hand-List (1906), 76
(error).
Balabac (Everett); Calamianes (Bourns & Worcester); Palawan
(Steere, Everett, Lempriere, Whitehead, Steere Exp., Bourns &
Worcester, Celestino, White).
Adult male.--Except wings and tail, nearly uniform pale gray, palest
on uropygium and crissum, much lighter gray than in A. striatus or
A. mindorensis; no black on forehead, lores, and chin. A male from
Palawan measures: Wing, 158; tail, 115; culmen from base, 29; bill
from nostril, 21; tarsus, 25.
Adult female.--General color pale gray like the male; rump and upper
tail-coverts white, barred with black; black bars on under parts
narrower than the white spaces, and under tail-coverts with only one
or two bars on each feather. An immature female from Palawan measures:
Wing, 145; tail, 108; culmen from base, 25; bill from nostril, 18;
tarsus, 25.
Young.--The young male is barred like the young female and the
young of both sexes have white fringes on the rectrices, remiges,
and wing-coverts.
"Fairly common; frequents high trees. Three males average: Length,
282; wing, 155; tail, 121; culmen, 32; tarsus, 23; middle toe with
claw, 26. A female, length, 279; wing, 150; tail, 114; culmen, 30;
tarsus, 25; middle toe with claw, 26. Iris pale yellow; bill, legs,
feet, and nails black." (Bourns and Worcester MS.)