The classification of cuckoos and their allies is a topic of debate. Experts have suggested that the hoatzin is distinct from others cuculiformes and should be classified in its own group. The same has been suggested for the turacos and their allies.
Cuckoos are medium-sized, slender-bodied birds that feed primarily on insects and insect larvae. Cuckoos inhabit forests and savannas. Cuckoos include roadrunners, koels, malkohas, couas and coucals.
Anis, also known as New World cuckoos, include three species of tropical birds that inhabit the southernmost stretches of Texas, Mexico, Central America and South America. These black-plumed birds differ from cuckoos in that they are not brood parasites.
The hoatzin inhabits swamps, mangroves and wetlands in the Amazon and Orinoco River basins of South America. Hoatzins have a small head, spiky crest and long neck. Thye are about the size of a pheasant and are brown with lighter feathers on their belly and throat.
There are 161 species of cuckoos, turacos and their allies.