If you learn the recorder, it isn't long before you find yourself playing different sizes, like F alto, sopraninos or basses, and the recorder isn't a transposing instrument. You soon get the hang of multiple mappings between fingerings and pitches. It's not so hard playing by ear.

What I do for most instruments is to use two notes as anchors: (1) the pitch you get with three left hand fingerholes covered, and (2) the one you get with those and three right-hand fingerholes covered. The rest is interpolation. So for instruments I play

                   (1)    (2)
  "D" instrument    G      D
  "A" instrument    D      A
  "G" instrument    C      G
  "F" instrument    Bb     F

This scheme doesn't correspond to the usual pitch names for wind instruments.

"D" instruments include: D whistle, C descant recorder, C concert flute, C melody sax, C Italian ocarina, G clarinet in the low register, C clarinet in the high register.

"A" instruments include: A whistle, Highland pipes at notated pitch, G alto recorder, G sopranino recorder, G alto flute, G Italian ocarina, and G clarinet in its high register.

"G" instruments are the G whistle, F alto recorder, F sopranino recorder, and C clarinet in its low register.

"F" instruments include the Bb clarinet in its low register (in its high register it's a "C" instrument).

I have a few other pitches, like a C# clarinet and a C# Italian ocarina - exercise left to the reader. Highland pipes at sounding pitch are a "Bb" instrument, which is the way Breton pipe music is notated.

Keep that scheme in your head and you can sight-read pretty near anything for any instrument in any key and any transposition.