There is another convention sometimes used for the F alto recorder of writing the music an octave lower than it sounds ("alto-up"). This never really took off outside Germany

Actually, Jack, that's not entirely true. Written music containing alto up parts is quite common. It's mostly renaissance music and it most commonly occurs when there are two treble parts.

Having said what I did earlier I think most recorder players have treated alto recorders as transposing instruments from time to time, but if you are going to play music for recorders you really don't do yourself any favours by starting off by treating the F recorder as a transposing instrument in spite of what Ebor Fiddler and Grishka are saying. I know one or two people who did that and they regretted it later as it took a lot longer to "convert" than it would have done if they had started off as most people do by learning to associate the fingerings with an alternative set of pitches.

Of course, if you intend to play purely by ear, it doesn't matter a damn.