Hoatzin

The hoatzin is a tropical bird that lives in the swampy forests and mangroves of South America's Amazon and Orinoco river basins. It's so unusual that scientists still argue about which bird family it truly belongs to.

• It's the only living species in its unique family Opisthocomidae.
• Hoatzins live near water in tangled forests and flooded mangroves.
• Scientists debate where this odd bird fits in the avian family tree.