The Rito are a race of bird-like people that live on Dragon Roost Island in The Great Sea which is the only known location of the Ritos. They have a tribal elder which serves as their king, in fact his son is called Prince Komali. None of the Ritos are born with their wings they must approach Valoo and retrieve one of his scales which will enable them to grow their wings, Ritos without wings are known as Fledglings.
According to Medli the Rito were once without wings, and had to use grappling hooks to climb Dragon Roost Island. It was through the sky spirit Valoo that they were allowed to use his magic scales to grow wings and fly. Using their wings the Rito became known throughout the great sea as mail carriers delivering mail to people across the scattered island without fear of the monsters that lurked in the waters below.
Many people believe they are descended from the Zora race as they make numerous refrences to the Zora people and Medli the current Earth sage shares the same blood line as Laruto the former eart sage and a Zora. They use the Zora's Sapphire as their royal symbol which was also the Zora's royal symbol. It is possible that the Zora's evolved into the Ritos because the gods did not want them to find Old Hyrule which was submerged underneath the sea.
Another possible theory is that the Ritos are the Sheikah's evolved form. They both have red eyes which was the distinguishing feature of the Sheikah and the Sheikah would have needed to evolve to survive the great flood. It is also believed that Dragon Roost Island is Death Mountain so it is possible that the Sheikah would have travelled up from Kakariko village.