First off, he's from the troll world, hidden behind a veil from mundane, but as ignorant as them of the dove maidens, or the centaurs, or the dragons -- fine, I can even give him a troll granddaddy in the best fairy tale style -- except that he's caught by dragons and turned into a dove.
And now he knows about dragons. And he's going to learn more.
And immediately he reveals to me that as a prince, he feels strongly about his people's safety. Very strongly. As in, does not see why the humans (and benign trolls) can't be protected from the man-eaters.
Going require more world-building. Because the bird maidens can interact with every world, and each of the magical worlds can interact with the mundane one except for the compulsions to keep their nature hidden -- but what will this demand? Splitting up the troll lands? Drawing the people into the bird maiden realm? But the last will require expelling those who can't be trusted; the people who come can interact with them, but not reveal things. . . .
I've always thought that the magical worlds divisions had been ad hoc, responses to danger and not philosophical divisions, but it looks even more ad hoc than before, and it's going to need more definition. I suspect it will show more signs of philosophy after the ending than at the beginning. . . .
And I'm sure someone's going to note that the dragons who kidnapped him were closer to the will-o-wisps and other tricksters than most dragons.
(I tried considering that he's not a prince, but he rejected that with haughty disdain. Just because the kingdom's the size of a postage stamp doesn't mean he's not a prince.)