Great Curassow

he male is black with a curly crest, a white belly, and a yellow knob on its bill. There are three morphs of female Great Curassows: Barred morph females with barred neck, mantle, wings and tail, rufous morph with an overall reddish brown plumage and a barred tail, and dark morph female with a blackish neck, mantle and tail (the tail often faintly vermiculated), and some barring to the wings. In most regions only one or two morphs occur, and females showing a level of intermediacy between these morphs are known (e.g. resembling rufous morph, but with black neck and faint vermiculations to wings). This species has a similar voice to several other curassows, its call consisting of a "peculiar" lingering whistle.

Females are somewhat smaller than males. It is the most massive and heavy species in the family but its length is matched by a few other cracids. Four other species of curassow (the Northern Helmeted, the Southern Helmeted, the Black and the Crested) are all around the same average length as the Great Curassow. In this species, standard measurements are as follows: the wing chord is 36 to 42.4 cm (14 to 16.7 in), the tail is 29 to 38 cm (11 to 15 in) and the tarsus is 9.4 to 12 cm (3.7 to 4.7 in). They have the largest mean standard measurements in the family, but for tail length.