vintage wild game bird duck call or maybe squirrel call, works!

I've tried this and I'm sure I don't know how to work it correctly - THINK it's probably a duck call, but the weird honks I made don't sound like any bird I'm familiar with, though they're really loud!

All I can say for certain is that the rubber looks good and works fine. This came out of an estate here in central Wisconsin, so it's likely a game bird native to this part of the world.