vintage Japan ceramic figurines, trio of ducks, mid-century mod decor

Trio of vintage ducks, about 3 1/4" tall, all marked Japan, all in very good condition. These have great MCM style and subtle coloring, a restrained retro look.

I see these Japan made ducks with the black heads and necks all the time, but I don't know what kind of duck, or duck breed they are, sorry! Google is no help.

I raised ducks and geese for eggs years ago, and am a lifelong duck and goose fancier. I'd love to know more about these birds, so if you know, please email me.