This genus forms one of the two major lineages of curassows. Their evolutionary history is not well researched compared to other curassows. They have also produced hybrids with peafowl, chachalacas, capercaillie, grouse, quail, curassows, pheasants and guans. They include tanagers, rheas, tinamous, curassows, antbirds, ovenbirds, and toucans. White Oak manages several breeding pairs of blue-billed curassows. Notable birds include guans, curassows, screamers, eagles and ducks. They are generally dull-plumaged, but the curassows and some guans have colourful facial ornaments. They are generally dull-plumaged, but the curassows and some guans have colorful facial ornaments. The chachalacas, guans and curassows are birds in the family Cracidae. The chachalacas, guans, and curassows are birds in the family Cracidae. Curassows are one of the three major groups of cracid birds.