The Hoatzin is a tropical bird native to South America. It is notable for having chicks that have claws on two of their wing digits. The hoatzin has an unfeathered blue face with maroon eyes, and its head is topped by a spiky, rufous crest. The long, sooty-brown tail is broadly tipped buff. The upperparts are dark, sooty-brown-edged buff on the wing coverts, and streaked buff on the mantle and nape. The under parts are buff, while the crissum (the undertail coverts surrounding the cloaca), primaries, underwing coverts, and flanks are rich rufous-chestnut, but this is mainly visible when it opens its wings.
Hoatzins are found in the Amazon and the Orinoco basins in South America. These birds live in riparian forests, swamps, and mangroves.
Hoatzins are non-migratory gregarious birds. They live in family groups or small flocks. They are active during the day and usually forage in the early morning and early evening spending the rest of their time roosting. When feeding they clamber around clumsily among the branches, and are quite tame (though they become stressed by frequent visits). Hoatzins are poor fliers; they only soar from tree to tree and need a lot of noisy efforts to move away when alarmed. These are quite vocal birds that communicate with a variety of hoarse calls, including groans, croaks, hisses, and grunts. Their calls are often associated with body movements, such as wing spreading.
Hoatzins are monogamous which means that males will mate with only one female and females will mate with only one male. They breed during the rainy season and nest in small colonies. Females lay 2 or 3 eggs in a stick nest in a tree hanging over water in seasonally flooded forests. The eggs are incubated around 32 days by both parents. The chicks usually remain in the nest for 2 or 3 weeks after hatching and are fed by both parents for up to 2 months. The begin tp fly at 55-65 days and reach reproductive maturity when they are 1 year old.
Hoatzins remain fairly common in a large part of their range and are not considered endangered. However, these birds suffer from habitat loss and in some regions, their preferred habitats, mangrove, and riverine forest are disappearing quickly. In Brazil, indigenous peoples sometimes collect their eggs for food, and the adult birds are occasionally hunted.
The IUCN Red List and other sources don’t provide the number of the hoatzin population size. Currently, this species is classified as Least Concern (LC) on the IUCN Red List but its numbers today are decreasing.