The hoatzin is the only bird known to ferment food in its foregut, the oesophagus and crop.
From the newscientist.com
Small wonder that scientists still puzzle over where the hoatzin belongs in the great avian filing cabinet.
From the independent.co.uk
It is a bird watcher's paradise, with nearly 600 species, including white-throated toucans, the phoenixlike hoatzin and vast swarms of parrots.
From the time.com
Another goal of this expedition was to find and capture a hoatzin, a bird whose clawed wings caused it to be considered an important link in the evolution of birds from reptiles.
From the en.wikipedia.org
Beebe made extensive documentation of hoatzin behavior through field glasses, but their plans to capture one were foiled when they had to return home early due to Blair breaking her wrist.
From the en.wikipedia.org
On the way we see several caiman and the tracks of a tapir, as well as five species of kingfisher, several striated herons, a cluster of hoatzin, and an owl-eye butterfly, to name but a few.
From the independent.co.uk
More examples
Crested ill-smelling South American bird whose young have claws on the first and second digits of the wings
The Hoatzin (Opisthocomus hoazin), also known as the Hoactzin, Stinkbird, or Canje "Pheasant", is an unusual species of tropical bird found in swamps, riverine forest and mangrove of the Amazon and the Orinoco delta in South America. ...
Album by Norwegian band Damp. Released 2005 at AIM Records.