Er ... about how many weeks, from birth, are elf owls fully fledged? Meaning, they have all their feathers grown in, and they can fly properly and stuff?
Also, if you could give me that exact same information with a maned owl as well, that'd be great.
You would have to do research on that subject-more than likely from a zoological source that studies ornithology most likely.
Both of those types of owls are not very common so more than likely you are going to have to do a bit of searching before you find the info you're looking for.