Adult.—Chin, upper throat, a band from throat to eye, and feathers above eye, all black, followed on throat by a white space which shades gradually into the dull chestnut-brown of lower throat and sides of neck and head; breast and sides black; abdomen, thighs, and crissum dull chestnut; back, rump, and wings brown, the rump lighter; primaries and most of the secondaries black, some of the latter edged with pale buff; tail-feathers pure white when fresh but soon becoming yellow or dirty buff. Entire casque and bill bright red. “Naked skin round eye yellow; iris red; feet brownish red; nails black.” (Everett.) Length of male, about 950; wing, 410; tail, 350; bill from nostril, 160; greatest length of casque, 160; greatest width of casque, 52; tarsus, 60.
“Adult female.—Similar to the male. Length, 914; wing, 381; tail, 295; tarsus, 56.
“Young.—Cheeks and upper parts of head blackish; rest of head and neck, rump, thighs, crissum, and under tail-coverts yellowish white mixed with rufous; breast and belly yellowish white mixed with blackish gray; back, wing-coverts, scapulars, and outer secondaries reddish brown, the wing-coverts tipped and the scapulars and secondaries margined with buff; primaries and rest of secondaries brownish black, margined on the outer web and tipped with buff; basal two-thirds of tail-feathers reddish brown, margined in all except the middle pair with black. Bill and casque dark black, except the base of the lower mandible and the extreme tip of the bill, which are blood-red.” (Grant.)
The three Philippine species of Hydrocorax do not differ in colors but they are easily distinguished by the color and shape of the bill and its casque. These large hornbills frequent forest, where they feed on fruits, usually in high trees. Their call is loud and penetrating and may be heard at a great distance. Their flight is rather labored and produces a great noise.
290. HYDROCORAX MINDANENSIS (Tweeddale).
MINDANAO CALAO.
- Buceros mindanensis Tweeddale, Proc. Zool. Soc. (1877), 543; Challenger Report, Zool. (1881), 2, pt. 8, pl. 3.
- Hydrocorax mindanensis Grant, Cat. Birds Brit. Mus. (1892), 17, 359; Sharpe, Hand-List (1900), 2, 64; McGregor and Worcester, Hand-List (1906), 55.
Basilan (Everett, Steere Exp., Bourns & Worcester, McGregor); Mindanao (Murray, Everett, Koch & Schadenberg, Steere Exp., Bourns & Worcester, Goodfellow, Celestino).
Adult.—Plumage as in H. hydrocorax but casque much narrower and bill with distal two-thirds white. “Naked skin round eye sooty black, yellow just before the eye, gular skin yellow; iris light yellow (light green in living bird); feet coral-red; nails dark brownish gray.” (Everett.) Length of male, about 915; wing, 390; tail, 300; bill from nostril, 155; greatest length of casque, 136; greatest width of casque, 42; tarsus, 52. Length of female, 863; wing, 365; tail, 290; bill from nostril, 136; greatest length of casque, 124; greatest width of casque, 39; tarsus, 48.
“Young.—Upper part of head and cheeks black; feathers on chin and breast white, blackish gray at base; rest of head, neck, rump, belly, flanks, and tail-coverts white mixed with rufous; back, upper wing-coverts, scapulars, and outer secondaries brown, the three latter widely tipped, and the last named also widely margined on both webs with white; rest of secondaries and primaries blackish brown, with a white margin on the outer web, gradually increasing in width on the outer secondaries; under wing-coverts brownish buff; middle feathers of tail have basal two-thirds brown, and the rest the basal half dull chestnut; the remainder of the feathers white; casque rudimentary. Bill black, yellowish at the tip; naked skin round eye and on gular region yellow; legs gray-green (in skin).” (Grant.)