Most of the action in the Zelda series takes place on land, which makes sense, but occasionally we get to visit other locations, like the sea and even the skies, each one with its own gameplay and story elements. Interestingly enough, unlike many other places which have a defined identity and an established history, the sky above Hyrule has yet to find its own mythos. Every time a place in the sky appears in a new Zelda game, it is depicted entirely different than the last time. Some time ago, we at Zelda Informer discussed the mysteries of the many people that have inhabited Hyrule skies and Dathen Boccabella gave us his thoughts on the subject. However, I see things slightly differently.
Throughout the series' history, we've visited the sky many times: first, in the Four Swords trilogy, in which Link travels to the Palace of Winds, known as the Palace of Vaati in Four Swords. But it wasn't until the final release in the trilogy, The Minish Cap, that we fully knew about the place. At the time, it was located on the Cloud Tops, populated by the Wind Tribe, who originated from the surface until they learned to control the wind and left Hyrule to live in the skies. However, by the time of Four Swords and Four Swords Adventures, they no longer dwell there and the clouds are deserted. What happened to them?
Then, in Twilight Princess we explored the City in the Sky, inhabited by the odd race known as the Oocca, who are known to be the closest beings to the Goddesses; they are closer to the deities than even the Hylians. Finally, in Skyward Sword, Link himself is a dweller of the sky; his hometown - being Skyloft, the village that was raised to the heavens by the Goddess Hylia after her battle against Demise - is separated from the rest of the world by a sea of clouds. Skyloft and the City in the Sky share some similarities - namely, both are settlements that lie above the clouds (while exploring the sky dungeon in Twilight Princess we see the clouds below the city) and are inhabited by the people supposedly closest to the Golden Goddesses. It has been repeatedly proposed that there might be some connections between them. It's suggested that the Oocca we meet in Twilight Princess descended (no pun intended) from the Loftwings, those awesome large birds that served as transportation for the people of Skyloft, the city in the sky during the Skyward Sword era. But what about the Skyloftian humans themselves? I for one, can't see the Oocca evolving from the Loftwings, especially when that raises the following question: what happened to Skyloftians then?
Now here is my personal view: some Skyloftians descended to the Surface to start the Kingdom of Hyrule (as it is implied by Skyward Sword's ending), while others stayed in Skyloft, developed advanced technology, transformed Skyloft from a village to a high tech city, and over time evolved themselves into birds, thus the Oocca.
At the time, Hylians and Skyloftians kept in contact directly, being basically the same race, until divergent evolution came and turned the sky humans into small birds, making it difficult to communicate with each other once they became separate races with different languages. Therefore, a messenger was needed to keep both realms in contact.
Ages later, some Hylians, missing the days of old, intended to go back to the skies, but since they couldn't fit with the Skyloftians anymore (because they were now the Oocca), they had to form a different civilization. Thus they settled on the clouds (between both cultures), hence the Wind Tribe.
Furthermore, while it is a mistranslation on NoA’s part, the line about Hylians being descended from the Oocca and that the Oocca are closer to the Goddesses than the Hylians themselves, makes sense this way: before Skyward Sword, humans were neither called Hylians nor descended from the Goddesses. It wasn't until Zelda from that game brought the blood of the Goddess to the race and properly started the Hylian bloodline that they eventually became a race on their own. So, basically, only post-Skyward Sword humans are true Hylians. Now, as they descend from a Skyloftian (basically a SS-era Oocca in my theory), saying that the Hylians descend from the Oocca is accurate, as is to say that the latter are even closer to the Goddesses, since Her Grace Hylia actually lived among them (albeit in Skyloftian form). Even disregarding said line, the original line in Japanese said that the sky beings (the Japanese term to refer to the Oocca) actually created Hyrule, an idea that can be interpreted in a non-divine way if we assume that they built Hyrule and founded the kingdom. Skyward Sword implies that Zelda and Link, and probably some of their peers, started the Kingdom of Hyrule, so in a way, the founders of Hyrule were sky beings that descended from the heavens just like the legends claimed in Twilight Princess.
Another important hint lies in the Temple of Time. In Twilight Princess, the Temple is where the Dominion Rod, an Oocca artifact, is hidden. Because of this, some believe that the Oocca might be the ones responsible for building said place, until Hyrule Historia revealed that it was Rauru who actually built it. Both ideas don’t have to be mutually exclusive though. It could be said that Rauru erected the temple with the help of his people, who in turn created the Dominion Rod. Rauru's name and appearance both hint at a close connection to Gaepora, a Skyloftian himself. Joining the dots, one can get the idea that the man who built the Temple of Time came from Skyloft and that his people would evolve into the Oocca while keeping their role as guardians of said temple, hence why Ooccoo is desperately looking for the Dominion Rod.
Finally, there’s the Clawshots. The only games they have appeared in are Twilight Princess and Skyward Sword; in the latter, they are one of the Goddess’ relics and are needed to fully traverse Skyloft, while in the former, one of the Clawshots is located in the City in the Sky itself. Coincidence? I don’t think so. Given that the Clawshots are divine objects, it is reasonable to believe that for the people of Hyrule and Skyloft they are sacred; thus one Clawshot was kept in the Sky while the other remained in the Surface. That way both races have a hold of the divine relic while it simultaneously symbolizes the alliance between the two cultures. It is also noteworthy that in order to gain access to the City in the Sky, one Clawshot is needed to reach and activate the cannon that makes such travel possible. This means that the Oocca were aware of a second Clawshot lying in the surface of Hyrule (otherwise the travel between both places would be impossible), an idea that is not difficult to conceive if we go by the theory that the Oocca are descended from the Skyloftians, the people whose Hero originally owned the two Clawshots.
It could even be said that Skyward Sword hinted at said evolution, what with the sky people bearing birdlike names, foreshadowing their future avian form.
As I said earlier, I’ve read and heard many times that people think that the Oocca evolved from the Loftwings, but the Oocca, with their human faces and mammary glands, seem more like birdlike humans than humanlike birds. Also, the City in the Sky looks like it was built for humans, not for birds, therefore I strongly believe that the Oocca were originally humans. That, or the Oocca evolved from breeding together both Skyloftian humans and Loftwings, but that's kinda gross... So I guess it’s easier to believe that the Oocca, as intelligent and advanced as they are, come from the humans, not from the birds.