For those with a bird cage that used rubber bellows, there is another
solution to the problem of no replacements.  I also repair birds in
cages as well as bird boxes and carved whistlers.  An associate of
mine with woodworking equipment will make a conventional bellows using
the whistle and air chamber from the failed bellows and cover it with
Zephyr skin.

With the greater air volume available, the sound is at least as loud
as the original.  Also, for those whose repairs might need replacement
parts, I do have some old and new ones in stock.

Moe Goldy