Size small; bill straight, compressed towards the end, nasal ridge well marked, beginning at the base halfway between culmen and commissure and extending half the distance to the tip; nostrils covered with plumes; feet very large, hallux well developed, fourth toe longer than third; a long crest on the occiput and nape; neck very slender; tail very short, but little exceeding the tail-coverts and only about one-third the length of the wing, the tail-feathers rounded at the end, outer pair distinctly shorter. Plumage black or dark olivaceous grey and buff. Both sexes have in the middle of the back a tuft of bristly feathers smeared with a viscid secretion having a peculiar resinous scent.
Only three species are known, of which one is peculiar to Java,, the others inhabit India and Burma.
Key to the Species.
A. Crown red in males, olive-grey like remainder of head in females, ruddy buff in young …………………….H. sordidus, p. 68.
B. Crown black with white specks in males, buff in females and young…………………….H. canente, p. 69.