The only bird known to ferment its food in the foregut, in a crop so large that the breastbone is displaced
Hoatzin — hence the name stinkbird.
Nature · Birds
Hoatzin
Least Concern · national bird of Guyana
Opisthocomus hoazin — Opisthocomidae
A strange, pheasant-sized bird of Amazonian and Orinoco waterside vegetation, with a spiky rufous crest, a blue face and red eyes. It is the only bird known to digest its food by foregut fermentation, in a vast crop full of bacteria, which gives it a manure-like smell and the local name stinkbird. Its chicks are born with claws on their wings, which they use to clamber back into the nest after dropping into the water to escape predators. It is the national bird of Guyana, where it is called the Canje pheasant.
How to spot them
- ▸A ragged, spiky rufous-brown crest, bare blue facial skin and crimson eyes
- ▸Dark brown above with pale streaks on the neck, chestnut belly and a long broad tail with a buff tip
- ▸An enlarged crop that pushes the breastbone out of the way, leaving a callused patch it rests on when perching
- ▸Clumsy, laboured, short flights; usually clambers through waterside branches instead
- ▸Harsh groans, hisses, croaks and grunts from noisy groups in riverside vegetation; a strong manure smell
How to know it
Its chicks are hatched with claws on their wings, and use them to climb back into the nest after diving into the water
Hoatzin — the claws are lost as the bird matures.
The national bird of Guyana, where it is known as the Canje pheasant
Hoatzin.
A leaf-eater that smells of fresh manure, and so is seldom hunted for the pot
Hoatzin — foregut fermentation of foliage.
The sole living member of both its family and, in most classifications, its own order
Hoatzin — Opisthocomiformes; its affinities remain unresolved.
Its generic name means 'wearing long hair behind', for the shaggy crest
Opisthocomus hoazin, the hoatzin.
Because of its wing claws, it was for a century wrongly linked to Archaeopteryx as a living missing link
Hoatzin — the resemblance is convergent, not ancestral.
Quick-fire facts
- •Length about 65 cm, weight about 700–900 g; found from Colombia and Venezuela to Bolivia and the Guianas
- •IUCN Red List: Least Concern
- •The crop and lower oesophagus hold the fermentation chamber, which may be 50 times the size of the stomach and account for a third of the bird's weight
- •It is the smallest known vertebrate foregut fermenter, and the only known avian one
- •The flight muscles are reduced because the sternum is displaced by the crop, making it a very poor flier
- •Chicks can swim, and drop from the nest into the water when a predator appears, climbing back with wing claws and bill
- •Its taxonomic position is one of the great puzzles of ornithology; it has been allied at various times with the game birds, cuckoos, turacos, doves and cranes
- •The name hoatzin comes from Nahuatl; the Guyanese Canje pheasant refers to the Canje River in Berbice
- •Groups are cooperative breeders: older offspring help feed and defend the next brood
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