The Great Curassow (Crax rubra) is a large, black pheasant-like bird with a yellow knob on its bill, curly black feather crests, and white below. They are the largest members of the family Cracidae, at 90 cm (36 in) and a weight of 4.7 kg (10.4 lbs). There are three morphs of female Great Curassows: Barred morph females with a vermiculated white head and neck, the red morph with a vermiculated black head and reddish brown plumage, and dark morph female with a black head and blackish brown plumage.
A monogamous species, the Great Curassow is distributed in rainforest from eastern Mexico throughout Central America, to western Colombia and northwest Ecuador. Its diet consists mainly of fruits, figs and arthropods.
Paleontology history of Great Curassow
The Great Curassow is the most northernly Crax species. It is part of a clade that inhabited the north of South America since about 9 mya (Tortonian, Late Miocene). As the Colombian Andes were uplifted around 6 mya, this species' ancestors were cut off from the population to their southeast. The latter would in time evolve into the Blue-billed Curassow. The ancestral Great Curassows then spread along the Pacific side of the Andes, and into Central America during the Pliocene and Pleistocene.(Pereira & Baker 2004)
Ecology
Due to ongoing habitat lost and overhunting in some areas, the Great Curassow is evaluated as Near Threatened on the IUCN Red List of Threatened Species. It is listed on Appendix III of CITES in Costa Rica, Guatemala, Colombia and Honduras. Of the subspecies griscomi of Cozumel Island with its distinct female, only a few hundred remain. Its population seems either to have been slowly increasing since the 1980s, or to be fluctuating at a low level; it is vulnerable to hurricanes.(del Hoyo 1994, BirdLife International 2004, see also Cozumel Thrasher)
This species has proven to produce fertile hybrids with its closest living relative the Blue-billed Curassow, and also with the much more distantly related Black Curassow (del Hoyo 1994)