(1330) Corydon sumatranus sumatranus.
The Dusky Broadbill.
Coracias sumatranus Raffles, Trans. Linn. Soc, xiii, p. 303 (1822) (Sumatra). Corydon sumatranus. Blanf. & Oates, iii, p. 6.
Vernacular names. None recorded.
Description. A concealed patch on the lower back white, suffused with yellow to crimson, caused- by the bases of the feathers of this part showing through; a broad band of white across the bases of the primaries, a bar of white across the ends of the tail-feathers, decreasing inwardly and the two central pairs without any white; throat and upper breast dirty brownish-white, the bases more white, the tips darker; remainder of plumage black, the lower plumage tinged with brown.
Colours of soft parts. Iris dark brown : orbital skin ami gape dark flashy-pink; upper mandible pale to dark, rather reddish, horny-brown; lower mandible pale yellowish-fleshy, darker neat the tip; legs and feet black.
Measurements. Total length about 270 mm.;; wing 129, to 138 mm.; tail 88 to 94 mm.; tarsus 25 to 26 mm.; culmen 26 to 28 mm. long and 27 to 28 mm. wide at the gape. Young birds are much browner, duller black than adults.
Distribution. Tenasserim, South to Sumatra; Siam, Annam and Cochin China. Birds from Borneo have been separated as Gory don s. brunnescens and have much browner, less black plumage.
Nidification. The Dusky Broadbill breeds in the Malay Peninsula from January to April, during which months nests were taken by Mellow, whilst Hopwood obtained one nest with young in March and other nests with eggs on Nwalabo in Tenasserim during June. The nests are huge pendant structures of grass, twigs, leaves, moss, roots, plant-stems and various other vegetable odds and ends, lined with green leaves. In shape tiny are gigantic pears with long drawn-out necks where attached to the supporting branch and with a large porch over the entrance. Below hang all sorts of. rubbish fastened on to the nest with cobwebs, this tail often hanging a couple of feet below the bottom of the true nest. One nest taken by Hopwood measured no less than seven feet from top to bottom. The nests are nearly always built in dense forest and very often on trees overhanging streams or pools. The eggs number two to four, with a groundcolour varying from pale dull cream to pale reddish-stone. The markings consist of reddish-brown small blotches and freckles, very numerous over the whole surface and almost obliterating the ground. In a few eggs they are less numerous and in one pair taken by Hop wood the blotches are rather larger, more scanty and show a few underlying marks of pale lavender. Twenty eggs average 29.4 x 22.1 mm.: maxima 34.9 X 24.0 mm.; minima 27.2 x 22.0 and 29.8 x 20.0 mm.
Habits. This large Broadbill is found in the plains and up to about 5,000 feet in the hills of Tenasserim. They frequent both thin and dense forest and seem to be very sluggish birds during the daytime, feeding and moving about principally in the mornings and evenings. Davison says that so stupid and lethargic are they that a party will allow nearly every member to he shot before they will trouble to move away. Kellow, however, informs me that they are much more alert after the parties break up into pairs and breeding commences. The call is said to be an often repeated, mellow note, in addition to which they utter a clear whistle as they fly from tree to tree.