AppearanceAt 78–100 cm in length and 3.1–4.8 kg in weight, this is a very large cracid. 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 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 , the tail is 29 to 38 cm and the tarsus is 9.4 to 12 cm . They have the largest mean standard measurements in the family, but for tail length.
The 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 , 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 . This species has a similar voice to several other curassows, its call consisting of a "peculiar" lingering whistle.
StatusDue to ongoing habitat loss and overhunting in some areas, the Great Curassow is evaluated as Vulnerable 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 smaller subspecies ''griscomi'' of Cozumel Island, 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. .
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.
HabitatA monogamous species, the Great Curassow is distributed in rainforest from eastern Mexico throughout Central America, to western Colombia and northwest Ecuador. In Mexico, it is absent from drier western coastal forests but does occasionally occur in dry areas of the Yucatan, Cozumel Island and Costa Rica. The Great Currasow spends much of its time on the ground, but nests and roosts in trees. This species is gregarious, occurring in groupings of up to a dozen birds, though occasionally birds can be seen alone. Its diet consists mainly of fruits, figs and arthropods. Small vertebrates may supplement the diet on occasion, including small mammals and small fledging birds. Unlike other cracids, such as guans, they feed largely on fallen fruit rather than pluck fruit directly from the trees. In Tamaulipas, it feeds largely on the fruit ''Spondias mombin''. Elsewhere, it may prefer the red berries of ''Chione'' trees.
The male Great Curassow may build the nest and attract a female's attention to it, though in other cases both members of a pair will build the nest structure. Two eggs are typically laid in a relatively small nest , each egg measuring 9.1 cm × 6.7 cm and weighing 200 g . The young curassow weighs 123 g upon hatching; 2,760 g as a half-year-old immature fledgling; and by a year of age, when fully fledged and independent of parental care, will be about three-quarters of their adult weight at 3,600 g . This species has been noted for its rather aggressive temperament, which has been regularly directed at humans when the birds are held in captivity. Undoubtedly, they have this inclination in order to repel natural predators, from both themselves and their offspring. Known natural predators of this species have included ocelots and ornate hawk-eagles, though chicks and eggs likely have a broader range of predators. When a potential predator is near their offspring, curassows have been noted to engage in a distraction display, feigning injury. When attacking humans, the curassows leap in fluttering flight and scratch about the head, targeting the eyes. Their lifespan in captivity has reached at least 24 years.
Some text fragments are auto parsed from Wikipedia.