The hoatzin is a species of tropical bird found in swamps, riparian forests, and mangroves of the Amazon and the Orinoco basins in South America.
Hoatzins are gregarious and nest in small colonies. Adult hoatzins are known to hiss, hoot, and yelp at predators.
They have a big claw on the end of their wings that they use to protect themselves. Hoatzin chicks are able to hide underwater to escape from predators, but adult birds cannot swim.
They also have a callused skin patch on their sternum where they rest their swollen gut.
Nicknamed the stink bird or the skunk bird, the hoatzin is also unique in being the only avian species with a digestive system that ferments vegetation in the stomach (same as a cow), enabling it to eat leaves and buds exclusively.
Hoatzin eats the leaves of the plants that grow in its marshy and riverine habitat. A study in Venezuela found that the hoatzin’s diet was 82% leaves, 10% flowers, and 8% fruit.
Hoatzins are seasonal breeders, breeding during the rainy season, the exact timing of which varies across their range. They lay two or three eggs in a stick nest in a tree hanging over water in seasonally flooded forests. The chicks are fed on regurgitated fermented food.
In Brazil, indigenous peoples sometimes collect the eggs for food, but the bird itself is rarely consumed, as hoatzin meat is reputed to have a bad taste.
Hoatzins can use their wing claws to climb on the limbs of trees and out of the predator’s reach.
Hoatzin population is threatened by habitat loss. Hoatzin predators include monkeys, hawks and snakes. Also their eggs are consumed by falcons, hawks and eagles.
This bird is also the National bird of Guyana, where the local name is Canje pheasant.