I'll take a stab at the second duck. It looks like a green and aventurine piece by Archimede Seguso. The colors are like the ones pictured on page 149 of Pina's Archimede Seguso book. It doesn't have the design, but I believe I have seen your design attributed to A. Seguso.
I don't know who did the first duck. It looks Seguso-ish, but I haven't seen these types of eyes before on Seguso. Ideas, anybody?