Hoatzin

Hoatzin is the main food of young leaves of rainforest plants. Hoatzin has a special stomach which contains bacteria that help break down cellulose and digest food (digestive system is similar to a cow). Digestion takes many hours, and since that accumulate and ferment food in their stomach for a long time, they become unpleasant odor, and that's why they are often called Stink Bird.

Because gastric particularly large and heavy (up to a quarter the weight of birds), causing the bird is difficult to fly. Hoatzin can not fly high, deep, and long. They were only able to fly a maximum of about 100 meters from a tree then fell on another tree.

As a child, the child hoatzin has two claws on each wing which helps them to climb and cling on branches of trees. Children hoatzin also known good swimmer in the water. However, with age, the claws on their wings grew smaller and even disappear altogether, as well as with their swimming ability. Video kids hoatzin:

As the only bird that has claws on its wings, the hoatzin has a physical resemblance to Archaeopteryx, a primitive bird that lived 150 million years ago.