Hoatzin

The Hoatzin, known by various other names like the stinkbird, skunk bird, Canje pheasant, or reptile bird, is a species of pheasant-sized birds found deep in the tropical wilderness and swamps of South America. It is a large, stubby bird that smells foul and is known to produce chicks with large claws on two wing digits, a physical characteristic, which has led some ornithologists and scientists to relate this species with the fossil of bird-like dinosaur Archaeopteryx.

Physical Description and Appearance

Size: Its size is similar to that of pheasants, with a measurement of 26 in (65 cm) by total length.

Weight: The mass of a Hoatzin can vary between 1.78 and 2.2 lbs (0.8 and 1 kg).

Color: It is characterized by a blue face with bright red eyes, a reddish-brown rufous crest on its head, a long, sooty-brown tail, with the upper parts of wings being dark, sooty-brown and underparts being rich, rufous chestnut.

Body: It has a small head, short, stout bill, long neck, and a large body; the pair of wing claws is lost when a young bird develops into an adult.

Wings: Its wings are broad, rounded, and comparatively short.

Distribution

The Hoatzin is distributed across the riparian forests and swamps in the Amazon and the Orinoco basins. It is also observed along the coastal areas of the Atlantic through Guyana, French Guiana, and Suriname.

What Kind of Habitats do Hoatzins live in

Since the Hoatzin is a tropical bird species, its habitat includes freshwater marshes, swamps, banks of rivers, gallery forests, lakes, and streams.

Lifespan

In the wild, the Hoatzin’s average lifespan is about 14-15 years, but in captivity, it can survive for up to 29-30 years.

What is Their Diet

Being a folivore, it primarily eats leaves of more than fifty different plant species, including mangroves and arums. Its diet comprises about 82 percent leaves, 10 percent flowers, and 8 percent fruits. It can sometimes accidentally feed on animal matter or insects.

Behavioral Characteristics

• The Hoatzin lives in flocks and nests in colonies, but if ideal nesting locations are scarce, it becomes territorial. When a breeding pair builds the nest, both the female and male birds violently defend it. They display ritual copulations, assume aggressive postures, and emit loud noises to inform others of their territory.
• Since it has unusually large crops, the Hoatzin cannot effectively utilize its flight muscles and keel, making it a poor flyer.
• It is a noisy species, and it communicates using different types of hoarse calls, such as croaks, groans, grunts, and hisses. The vocalizations are associated with various body movements like wing spreading.
• It gathers in flocks and moves in trees to feed on leaves, usually foraging in the early morning and evening.
• An adult Hoatzin spends much of its time roosting and regurgitating or digesting its meal.

Adaptations

• The unique wing claws of young Hoatzins make them expert climbers.
• Young Hoatzins use flapping motion of their specialized wings along with alternating leg movements to swim under water.
• The Hoatzin is the only bird species to possess a specialized digestive system that allows it to eat leaves. It has an enlarged crop consisting of symbiotic bacteria, which help in breaking down and digesting the leaves, just like the rumen in cows and other ruminants.

Reproduction and Mating

The Hoatzin starts breeding after it attains sexual maturity at one year of age. As a seasonal breeder, it mates in the rainy season, the timing of which can vary across its territory. After mating, it builds nests on the branches of trees located 6-15 feet over the surface of water. It usually lays 2-3 eggs, which hatch after an incubation period of 32 days. The hatchlings remain in the nest for 14-21 days after they hatch.

Conservation

The Hoatzins, quite clearly spotted in the wild (because of their striking colors, weird shape, and poor flight), are not considered endangered. In some countries, like Brazil, their eggs are occasionally collected and the adult birds are hunted for food by the native people. However, this is quite rare because the Hoatzins leave a bad taste in the mouth. Even though the destruction of Hoatzin’s habitat is a growing threat in South America, the IUCN has listed this species as ‘Least Concern’.

Interesting Facts

• The Hoatzin has been named the ‘stinkbird’ derived from the foul odor caused by the break down and bacterial fermentation of food in its unique digestive system.
• Immediately after hatching, the Hoatzin chicks can use their wing claws and oversized feet to move on tree branches without losing their balance.
• When predators like snakes, hawks, and monkeys approach, the chicks use these claws to climb on the smaller branches of trees or hide among the thickets and escape the predators. They would also jump into the water if they cannot keep the predators away in the trees.
• The Hoatzin, called the Canje Pheasant in Guyana, is their national bird.