is a primitive chicken-sized bird of South American swamps, principally in the
The young possess two large claws on each wing which are shed during growth , a trait that has led some scientists to link the species with Archaeopterix, the fossil of the dinosaure era.
The hoatzin is the only bird with a digestive system that ferments vegetation as a cow does, which enables it to eat leaves and buds exclusively. Hoatzins feed on swamp plants, grinding foliage in a greatly enlarged crop (not the gizzard, as in other birds). A large rubbery callus on the bird's breastbone acts as a tripod to keep it from falling over when its stomach is distended.
They swim well and can dive. Adults can fly clumsily for short distances, but they spend most of their time perched, digesting their leafy food.
The hoatzin is about
hoatzin (Opisthocomus hoazin) (2012) . Encyclopædia Britannica Ultimate Reference Suite. Chicago: Encyclopædia Britannicahttp://en.wikipedia.org/wiki/Hoatzin