Like other curassows, this large forest bird spends much of its time stalking about on the forest floor in search of fallen fruits, berries and seeds, as well as large insects and the occasional small animal (4) (6). The great curassow is monogamous and travels in pairs or in small groups, with the male curassow leading his family and uttering a high-pitched whining whistle when there are signs of danger (4) (6). At other times the group communicate by low-pitched grunting sounds (4) (6). When disturbed, this shy and cautious bird often runs rather than flies away, but will also seek protection up in the trees (2).
The great curassow builds its nest of leaves and twigs in forks and depressions in trees (4), into which the female lays two eggs between March and May (9). Once hatched, the chicks develop rapidly and are capable of flight at around 20 days (2), after which they soon leave the nest (2).