Or maybe he flew off to the secret location where (a certain person) really is, in hiding.
Fawkes is an interesting character. Besides his healing tears, he also has the power to apparate within the bounds of Hogwarts -- and to take someone with him if they grab his tailfeathers.
Just out of curiosity, I really don't recall the answer to this, has it ever been mentioned just what phoenix shed the two tail feathers that are in the wands of Harry and Voldemort? Could it have been Fawkes?
And speaking of wands, how the heck had Voldemort's wand all those years? Seems like something somebody should've been looking for.
TS
It was Fawkes tail feathers. It was told to Harry by Dumbledore in the Goblet of Fire. He told him that was why Voldemort couldn't use his wand against him while dueling. :) I guess Voldemort had his wand or possibly wormtail. I reread the books every once in awhile to see if I have found any new clues. :)