how do dragons fly? (Spoilers all books to end DH)

['thul]

Big animal does not equal heavy... you must not forget that, assasin... Also, while dragons in RotE are fairly large, their wings are also proportionally larger. giving them hollow bones (like birds) makes their main weakness reduced. RotE dragons keep their wings folded up to almost nothing when not in use, but fold them out to be much larger than even the largest sails on the largest ships when in use... Had their ability for flight been magical in nature, it would not have been necessary for the dragon "heeby" to practice continually on flapping to gain flight... such exercise is only natural when the ability it concerns is naturally possible...

your words appear quite correct to this one, Farseer...