The hoatzin lives in tropical forested wetlands of 200 to 500 meters elevation. The hoatzin is an arboreal species and is folivorous, feeding on leaves, flowers and fruits of a small number of plant species. It has a large crop that uses bacteria to break down the leaves that it eats. The hoatzin is unique because it has bacteria in its crop that breaks down its food while it is still in the crop.This is a process called foregut fermentation. It rarely drinks because its diet includes water.[7] The hoatzin is sedentary and widespread in suitable habitat. They are noisy birds, calling in unison, uttering large numbers of varied sounds.
In addition to foregut fermentation, the hoatzin has a highly modified skeleton to accommodate its large crop, and in the young of this species, wing claws at the wrist joint which are used to climb among the branches of the nest tree.
