The hoatzin (WHAT-seen) is a bird of tropical South America. It builds its nest directly over streams and other bodies of water. when a hoatzin chick is threatened in its nest by another animal, such as a monkey. it dives into the water and swims away. It often makes its escape by swimming underwater. To get back home, the chick uses something that few other birds have: wing claws. Digging in with the two claws it has on each wing-along with its bill and its feet-the chick climbs a tree. It usually diesn't return it. When the hoatzin chick is about 10-15 weeks old, it begins to learn to fly. Once flies it loses its wing claws.